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05 February 2014 - M4.4 flare in NOAA 1967 - This movie was created from 15 images made with a hand-held GSM behind a 7.5 mm ocular and a PST on 2 February. Visually, the eruption was even more stunning. NOAA 1967 is one of the largest and most complex regions so far this solar cycle. It has produced numerous M-flares, but no X-class flares so far. More info on this active region's flaring activity in this week's STCE Newsletter.

25 October 2013 - NOAA 1882 produced 2 X-class solar flares today: An X1.7 peaking at 08:01UT, and an X2.1 at 15:03UT. The sunspot group is still close to the southeastern solar limb. It has a relatively simple configuration, however the main (trailing) spot has a mixed polarity ("delta-spot"). Coronagraph images from SOHO indicate that a fast (speeds between 1000-2000 km/s according to various sources) halo CME was associated to the second X-class flare. A glancing blow is expected on 27 October, which may create a small geomagnetic storm.

This high activity is following close on the last week's flaring activity from the impressive sunspots NOAA 11875 and 11877, with a M9 flare early on 24 October by NOAA 11877.

Further activity can be followed at the Space Weather Page.

25 July 2013 - Solar activity has not been particulary exciting the last few weeks. So here's a graph showing the evolution of the hemispheric sunspot number (taken from my Solar Cycle 24 Tracking page). Data include the preliminary SIDC results from June 2013. Though a maximum occurred late 2011 and activity has been pretty much decreasing ever since, most scientists expect that the true maximum is still to come. This may be a bit lower than the 2009 prediction of 90, and may even occur in 2014. See here for more information.

13-15 May 2013 - Wow!... - An as yet unnumbered sunspot region (probably going to be NOAA1748) that is currently rounding the east solar limb has produced 2 X-class flares over the last 16 hours: An X1.7 at 02:17UT, and an X2.8 peaking at 16:05UT. The very latest SDO-imagery show a complex and big sunspot region with mixed magnetic polarities. This means that it is prone to more strong solar flares of which the intensity can only be predicted as we get a better view on this region. According to STEREO-data, this sunspot group is not the reappearance of C-flare active NOAA1726, but developed on the solar backside over the last 2 weeks.

The X2.8 is the third strongest flare of this solar cycle (after X6.9 on 9 August 2011 and X5.4 on 7 March 2012). We have to go back already to 23 October last year for the previous X-class flare (X1.8 in NOAA1598, see this STCE-Newsitem for further details on SC24 X-class flares). The last time we had 2 X-flares on one day was 7 March 2012 (NOAA1429 and NOAA1430 - see further down this page), and the last time we had 2 X-flares by the same sunspot group was on 13 September 2005, when NOAA0808 produced 2 X1 flares. That region actually managed to produce 3 X-class flares on one day on 9 September 2005 (X1, X3 and X6), and it also produced the last X10+ flare (an X17 on 7 September 2005). See my Archives and to recall this very active episode from the previous solar cycle.

If this new region is going to be anything like NOAA0808, then we sure may brace ourselves for the next few days. Underneath I've put some imagery together to follow the new region, its (flare) activity, and its impact on Earth. Just hit the F5-button to have the latest updates.

UPDATE 14 May - 04:45UT: NOAA1748 produced another X-class flare, this time an X3.2 peaking at 01:11UT, making this now the third strongest of SC24. Preliminary analysis from coronagraphic images indicate that, again, the CME seems to be directed away from the Earth. Some proton enhancement has been noted starting prior to this flare. It is not sure whether this is due to the second X-eruption from NOAA1748 (most likely), or to an eruption on the west-side yesterday afternoon. The latest visual and magnetic imagery indicates sunspot region NOAA1748 is a small, but compact nest of opposite magnetic polarity sunspots. Thus, more (major) flares remain likely, with increased geo-effectiveness (from high energetic protons and from CME's).

UPDATE 15 May - 04:30UT: NOAA1748 produced its 4th X-class flare, this time an X1.2 peaking at 01:48UT. At the time of this writing, already enhanced proton flux seems on the rise again, maybe reaching event treshold in the course of the day. Preliminary analysis from coronagraphic images indicate that the CME seems to be directed away from the Earth, but more data are needed for a final conclusion. The latest visual and magnetic imagery indicates sunspot region NOAA1748 has loosened up a bit, but still contains at least 2 locations with opposite magnetic polarity sunspots close together. Thus, more (major) flares remain likely, with increased geo-effectiveness from high energetic protons and from CMEs as the region turns further onto the solar disk.

21 April 2013 - ATTENTION! - The magnetic configuration of NOAA 1726 is mixed up and very similar to NOAA 1263 which produced the strongest flare so far this solar cycle (X6 on 9 August 2011). Indeed, the trailing part of one active region is bumping into the leading opposite polarity part of another region. In this case, the latter consists only of small spots, so M-flares are favored over X-flares, but there's no doubt NOAA 1726 is about to produce a strong flare today or tomorrow (maybe even longer if the magnetic configuration continues to exist). The region is very bright in H-alpha (see GONG H-alpha network), and some very nice surges were seen following the series of C-flares since last night (GONG/Learmonth clip, and GONG/Udaipur image). Watch the evolution and flaring of this region during the next few days as it keeps transiting the solar disk.

12 April 2013 - Contrary to some announcements in the media here, here and here, there's NO chance that aurorae will be visible tomorrow from Belgium. The media conclusions are -once again- based on an overestimate of the potential impact of the full halo CME. The reason for this is that the associated flare (yesterday's M6.5 proton event in NOAA 1719) is not considered as strong enough for producing an extremely severe geomagnetic storm (Kp=9 on the Richter scale of geomagnetic disturbances), which is a requirement for polar lights visible from our country. Current predictions from the SIDC are major storm conditions (Kp=7), which means polar light obviously visible from Scandinavia, Ireland and Scotland, and possibly also from the northern part of The Netherlands, Germany and Poland (low above the northern horizon and with clear skies). See this NOAA chart.

Follow the progress of the geomagnetic disturbance with the real time maps underneath: ACE's coverage of the solar wind, POES' observation of the auroral ovals, and the geomagnetic Kp-index as measured by resp. NOAA (global) and Dourbes (Belgium).

10 March 2013 - NOAA 1692, which is old active region NOAA 1678, seems a lot less complex and inactive than expected while it is rounding the east solar limb and becoming better visible from Earth. In case this sunspot group has really run out of steam, there is still comet Pan-STARRS that can be followed as it is transiting through the field of view of STEREO-B's heliographic imager HI-1. In the next few days, this comet should become visible to observers of the northern hemisphere, and it is very likely to be a naked eye object.

09 March 2013 - I'm back!... - Old active region NOAA 1678, which developed quickly 2 weeks ago while approaching the solar west limb, is now making an encore performance as it rounds the east solar limb. During its backside transit, the region was very active producing numerous strong flares and halo CMEs, as imaged by the two STEREO-spacecraft and SOHO. See the STCE Newsletters of 1 March (Fast rise of NOAA 1678) and 7 March (10 Little Indians) for more information. SDO/HMI-images of early this morning show a massive sunspot at the east limb, while SDO/AIA-images show plenty of coronal activity over this region. Watch the evolution of this region during the next two weeks as it transits the solar disk.

23 January 2013 - The latest results of Hi-C, the High-resolution Coronal Imager, were announced today during a press conference. Material can be found at this NASA-website. Note Hi-C was a solar telescope that flew on 11 July 2012 onboard a sounding rocket and collected EUV-pictures for only 345 seconds. Its resolution (about 150 km) is the best ever, even 5 times better than SDO's already legendary AIA-instrument, thus raising the bar for any future solar telescopes. This improved resolution and the 5-seconds image cadence were crucial in the new discoveries. The most notable result is that twisting and braiding of the solar magnetic field (coronal loops), with subsequent relaxation and energy release, has been observed. This process could supply sufficient energy that, when dissipated, could heat the solar corona thus explaining the mystery of why the corona is so much hotter than the solar surface. Obviously to be confirmed by future solar missions.

05 January 2013 - The SC24 Tracking page has been updated. SC24-maximum still expected for 2013.

27 December 2012 - A movie was added showing some of the most interesting solar events in 2012. More details on each of these events can be found in the STCE-Newsletter's digest.

Best wishes for the New Year!

13 November 2012 - Great total solar eclipse in Australia. Screen shots from live broadcast in Port Douglas (top 2 images at 20:38UT and 20:39UT) and from Cairns/Palm Cove (bottom image at 20:41UT). Eclipse also seen by PROBA-2.

1 September 2012 - A movie was added showing the spectacular Hyder-flare that took place yesterday after the eruption of a long and solid filament. More details in the description box. The item was also discussed in the latest STCE-Newsletter.

31 August 2012 - The last issues of the STCE Newsletter covered the following topics:

31 August 2012 - I've updated the page that provides an overview of all satellites monitoring the solar-terrestrial relationships, as well as the page that provides an overview of all white light flares (WLF).

3 August 2012 - This week's issue of the STCE Newsletter has a special on the high speed CME unleashed by a powerful flare in NOAA 1520 on 23 July 2012.

26 July 2012 - This week's issue of the STCE Newsletter has a special on the 19 July M7-flare that liked to play hide-and-seek with the solar observers. Also some words on proton events and long duration events (LDE).

19 July 2012 - Some details on last week's X1.4-flare in NOAA 1520 and the long lasting geomagnetic storm 2 days later can be found in this week's STCE Newsletter. Emphasis on the location of the flare (movie at YouTube), the radio observations of the event, and the composition of the storm.

12 July 2012 - An X1,4-flare occurred in NOAA 1520 this afternoon (16:49UT). Movies of the event at GONG, at PROBA2, and at LMSAL (SDO). A particle cloud was ejected as can be deduced from Humain's radio-observations (16:28UT), and preliminary Stereo B(ehind) images. The latter indicate an Earth directed CME. Also, proton-levels have already risen above event threshold - See SWPC's updated (top) graph. It will also be worthwhile to watch any effects of the geomagnetic disturbance from this eruption on the other graphs.

11 July 2012 - A summary of the very active region NOAA 1515 can be found in this week's STCE Newsletter. Comments on the position of the 30 M-flares that were produced, comparison with previous solar cycles, images of the the splitting of the main spot, as well as a special on the M6.9 limb flare, are included.

30 June 2012 - This morning I photographed a nice C4,4-flare in NOAA 1514, peaking at 08:30UT. I used a simple handheld GSM-camera behind a 7,5mm Super-Plössl ocular. The PST was fixed on an azimuthal mount. The images also show NOAA 1515 to the upper right, as well as a big, active prominence. To the lower right, the main spot of NOAA 1513 can be seen (northern hemisphere). More movies of the event at LMSAL and the GONG H-alpha Network.

23 June 2012 - A beautiful prominence eruption occured earlier this morning at the northwestern solar limb. Movies of this event can be found at the websites of SDO, GONG H-alpha, and PROBA-2 Science Center. Great close-up movies are at LMSAL/Solarsoft.The extent of the eruption is very well visible in the PROBA-2 wide-field images, whereas the LMSAL close-ups and the GONG-movies show the untwisting of the erupting prominence in full detail.

Interestingly, the eruption in H-alpha was already completely over when the GOES-15 x-ray flux reached its C2,7-maximum at 07:50UT. However, the PROBA-2 and SDO-images clearly show maximum brightness after the GOES-15 x-ray peak (estimated at around 08:20UT). This can be seen in the collage underneath, with horizontally the time in UT, and vertically the GOES-15 x-ray flux (1-8A; red curve).The series of 6 images are coming from (top-to-bottom) the GONG H-alpha network (Learmonth), PROBA-2/SWAP 174, and SDO/AIA094, and are taken at 06:20UT, 06:50UT, 07:15UT, 07:50UT, 08:20UT and 08:50UT. All this is a consequence of the configuration and position of the eruption, and of the differences in wavelength in which the flare was observed.

09 June 2012 - I added a list of satellites (past and still operational) involved in the research on solar-terrestrial relationships on my Solar Cycle Page.

20 May 2012 - A movie was added showing the changing appearance of NOAA 1471's main spot. More details in the description box.

26 April 2012 - Dipole or quadrupole? Much ado about nothing - A perfectly innocent press release on the solar magnetic configuration by Japanese scientists working with the Hinode satellite ended up on several blogs worldwide after a Japanese journal published a climate-hyped article on its website.

As clearly indicated by the Japanese scientists, this magnetic field reversal on the solar poles happens near the maximum of the sun's sunspot cycle, and it takes time. In fact, it is quite slow (1-2 years) and can vary in periods of months. The timing during which this reversal takes place, can differ from one pole to the other. Hence, at times, this may result in the sun having two poles with the same magnetic polarity. This is nothing extraordinary and has happened for example also during the previous solar cycle in 2000-2001 (see also this Science-at-Nasa article, a highly recommended reading).

As the prominent scientist Leif Svalgaard explains on the WUWT-website (his comments on 21 Apr 10:42, 11:18 en 11:32), it then can happen that the normal dipole field connects to large patches of opposite magnetic polairy located near the solar equator, if coincidentally present at that time. Hence, the magnetic sun can ***temporarily*** look like a magnetic quadrupole. This has happened in the past (e.g. 1980), and this may occur again in the coming months as the sun happens to have a similar magnetic configuration. Compare e.g. the magnetograms of February 1980 with this one of April 2012. For 2012, the reversal at the solar's northern pole has to persist and permanently retain the new magnetic polarity. As one can see from the WSO-magnetograms, this is not yet (entirely) the case.

I would like to emphasize that the magnetic fields in the equatorial areas are no solar "poles". It's not like the solar poles change every so many months from magnetic polarity or even from location or so. From the MSFC's magnetic butterfly diagram, one can easily see that at each pole one magnetic polarity is ***gradually*** neutralised (hence the “0” in the WSO-graph) and replaced by the new (reversed) polarity elements which are nothing more than the magnetic remnants of the trailing sunspots of groups from the new solar cycle: nothing more than the solar dynamo in action! This is briefed in every elementary course on the solar dynamo (e.g. slides 10-14 from the presentation I gave in november last year).

So, is this the end of the world? Of course not. Do we need to attach all kind of doom scenarioes (e.g. little ice age, a new Maunder minimum) to it? Idem dito. In my opinion, the Japanese scientists only wanted to point out the detail with which the Hinode satellite observes the magnetic fields at the solar poles, and how it can contribute to a better understanding of the solar dynamo and the creation of magnetic fields. Nothing wrong with that.

Update : "TBar1984" made a great and inspiring YouTube-movie on this topic. Congrats!

17 April 2012 - A movie was added showing the spectacular explosion (M1-flare) that took place yesterday at the Sun's east limb. More details in the description box.

02 April 2012 - The preliminary average sunspotnumber (SSN) for March is 64,2. Looking at SIDC's daily numbers, at first glance one might get the impression that March was a relatively stable month, with most days having sunspotnumbers between 50 and 80. Not so when looking at the sunspot area (from NOAA's Weekly; right axis), which clearly shows March's bipolar face: NOAA 1429 dominating the first half of the month both in sunspots as in sunspot area and flare activity (C, M, X-flares), while the last two weeks were dominated by multiple, but small and flare-inactive sunspot groups.
Though former region 1429 is now (nearly) spotless region NOAA 1451, H-alpha imagery shows important group filaments in this area. These may give rise to M-flares if the underlying magnetic fields become unstable, similar to the 7 June 2011 eruption.

UPDATE 13 April 12: I added a movie showing the chromospheric activity over the last weeks with the final eruption of the filament in NOAA1451 on 7 April. Though spectacular, the flare itself was only a modest C2.

24 March 2012 - While I was observing the Sun in H-alpha this morning, NOAA 1445 produced a very nice solar eruption. The quick-and-dirty drawings underneath show the look through the eyepiece (33x) of a modest PST, and are compared to the corresponding H-alpha images (cut-outs from the large pictures) from the GONG H-alpha Network. Despite the small diameter of this telescope (4 cm), and the impressive dynamics during the eruption, details of the eruption as well as of the post-flare loops were well observable.
Initially, the strength of the flare was unclear, as GOES-15 data were missing. However, SIDC has extrapolated the PROBA-2 data and concluded this was a M1-flare, which seems to be in proportion to the brightness and area of the flare as seen in H-alpha. Update: NOAA has this flare now as a C7,2.
I've made a small movie of this event, combining a AIA171-clip, a AIA304-clip, a Combo AIA304/1700-clip, and a H-alpha clip. The result is this YouTube-movie. Timespan is 3 hours for each subclip (08:30-11:30UT). The AIA171 clip shows the origin of the event: a reconnection in the corona over the active region (in the initial images, a void can be seen billowing away from the blast side). The Combo-clip shows very well the position and evolution of the flare relative to the sunspots of NOAA 1445. The AIA304 and H-alpha clips show more details of the flare itself and the coronal loops (notice the diffuse region on top of the initial coronal loops).
In the next few days, more flares can be expected from this region.

Bottom images courtesy of the GONG H-alpha Network

07 March 2012 - Clips of today's X5,4-flare by NOAA 1429 were put together in this YouTube-movie. More details in the description box. The sunspotgroup has become even bigger (1458 MH) as measured early this morning on Kanzelhöhe drawings. NOAA 1429 still has all the potential to produce further strong M- and X-class solar flares, which may be even more geo-effective.

The images to the left and in the middle show the latest SDO intensitygram (20:15UT) and magnetogram (19:45UT) of NOAA 1429. Notice the shear in the penumbra and the elongation of the sunspots along the inversion line. Also, notice most northern polarity is on top (white, magnetic field coming out), and southern to the bottom (black, magnetic field returning to the solar surface). This may indicate a magnetic field of the CME parallel to the geomagnetic field (southward oriented), hence a good magnetic connection and thus strong geomagnetic disturbance can be expected (we'll see how it goes...). The H-alpha image (GONG/Learmonth) to the right shows the region at 03:00UT this morning. Clearly, one can see the post-flare coronal loops as very fine dark lines hovering above the group's magnetic inversion line. This kind of features can be observed even with very small H-alpha telescopes like a PST (see these drawings of the 30 July 2005 X-class event).

Courtesy of SDO (NASA) and the AIA consortium, and of the GONG H-alpha Network

06 March 2012 - I added a YouTube-movie showing the visual evolution of NOAA 1429 over the last few days. The group is really big: 1299 MH (about 8 times the surface area of the earth) as measured early this morning on Kanzelhöhe drawings. It's also an easy naked eye object (see diagram). However, please use a safe welding or solar filter, or best of all: those eclipse glasses!
The sunspotgroup seems to be falling apart a little bit, but there's still plenty of magnetic mixture to produce more M- and X-class solar flares.

05 March 2012 - I added a YouTube-movie on the recent solar flare activity in big sunspotgroup NOAA 1429 during the last couple of days. As usual, more details on this event can be found in the description box. The X1-flare from early this morning might deliver a glancing blow to the earth's magnetic field (see SIDC-press release). The proton enhancement, starting about 12 hours after the M2-eruption, has not reached the level required to be catalogued as a proton flare. The region is capable of more strong flares in the days ahead, of which radiation and CME's will be more earth directed.

NOAA 1429 (left) and its interaction with NOAA 1430 after the M2,0-flare on 04 March 12.
Courtesy of SDO (NASA) and the AIA consortium

26 February 2012 - I added a YouTube-movie on the spectacular filament eruption that took place early 24 February. More details on this event can be found in the description box. SIDC and GSWL predict Earth could receive a glancing blow of the CME late today or tomorrow. The proton enhancement, starting about 20 hours after the eruption, did not reach the level required to be catalogued as a proton flare.

18 February 2012 - Hemispheric asymmetry during SC24 - Regular solar observers have already noticed that the northern solar hemisphere is dominating this cycle's activity for quite some time now. This is by no means an exceptional occurrence (see this chart with the evolution of the hemispheric sunspot area since 1874). The two charts aside the SDO's 01 August 2011 solar image underneath depict some details of the ongoing asymmetry. The top graph shows per hemisphere the smoothed average latitude of the sunspot groups, while the bleached curves show the smoothed number of new groups that appeared each month. The bottom graph shows the hemispheric evolution of the sunspot area (SA; right axis) and of the number of M- and X-flares (left axis).

Some conclusions that can be drawn:

31 January 2012 - Flare Forecast Evaluation - On a daily basis, NOAA/SWPC and SIDC predict the likelihood on solar flares. A crude evaluation of the confidence one can have in these predictions, is to bin the probabilities in "< 50%" and "> 50%" and compare them with the actual (non)-occurence of these flares for that particular day (0 or 1). Based on NOAA's RSGA and SIDC's Daily Bulletins, a comparison was made for 2011. The results for M-flare prediction are shown underneath.

As can be noted, SIDC performs a few % better than NOAA (87% vs. 83%; green columns), but it must be taken into account that SIDC makes its prediction at noon, and NOAA 12 hours earlier. A fair comparison would thus require for SIDC to regroup the flare occurrence from noon till noon of the next day. Both organizations have the same error rate (about 8-9%; red column), error meaning here not having predicted days with at least 1 M-flare. Note these M-flares include filament eruptions like on 7 June 11, or beyond/near the limb events like on 28 January. Nonetheless, SIDC really seems to be better when it comes to avoiding false calls (no eruption when one is predicted; orange column): When SIDC has a > 50% probability on M-flares, they are correct in almost two thirds of the cases. For NOAA, this is only fifty-fifty.

Obviously, the study can also be performed for C-flares, but NOAA has no probabilities for this class and thus no reliable comparison is possible. It's interesting to note that neither NOAA nor SIDC had a day with > 50% probability on X-class flares, meaning all of the 8 X-flares in 2011 were missed. If one assumes this is a difficulty in estimating the strength of the potential flare, and thus allowing that a > 50% probability on M-flares includes also the X-class, then SIDC outperforms NOAA 7 to 5.

28 January 2012 - Yesterday, NOAA 1402 sent us a departing shot (movie from galaxy387 and Solarwatcher) while rounding the western solar limb: An X1,7-flare peaking at 18:37UT. That NOAA 1402 produced another flare was not such a surprise: the group seemed to be decaying, and the restructuring magnetic fields then sometimes produce flares. What was not anticipated (NOAA, SIDC), was that this flare made it all the way into the highest X-ray class. Except for the x-ray radiation and the proton event (about 800 pfu (S2) at the moment), Earth will not be influenced by this event. Indeed, the spectacular CME seems to be directed completely away from us. The STEREO-satellites now have the best view on the further evolution of this "bad boy".

23 January 2012 - Early this morning, NOAA 1402 produced an M8,7-flare. The eruption occured in the same area (i.e. along the same inversion line; see before and during the flare) as the M3-flare from 19 January (GONG H-alpha).
The flare has sent a complex, fast-moving CME (STEREO Behind) towards the Earth that could produce a geomagnetic disturbance on 24 January.
There is also a strong proton-event (S3-radiation storm; see NOAA-scales for risk) in progress. Its level is actually topping 3000 pfu, which makes it the strongest event so far in SC24 and the strongest since May 2005 (see NOAA/SWPC list). The protons are visible in SOHO's LASCO-images (also at Spaceweather).

The website of the SIDC has a great overview of the recent events on the Sun and near Earth, as well as a nice SDO-movie. Some great YouTube movies also by, VIDEOVAX, this one, and another containing a GOES-15's SXI-clip. The latest SXI-images show the development of a new cusp, and the latest GONG-movies show there's still some filamentary structure present...

20 January 2012 - A beautiful long-duration M3-flare erupted yesterday along the magnetic inversion line near region 1402. An inversion line separates regions of opposite magnetic polarity and was in this case clearly defined by a fine, right-angled filament "left" from the main spot (see GONG H-alpha images underneath, taken at resp. 11:00UT, 15:15UT and 19:00UT).
As the filament was ejected, hot regions came into existence in the area where magnetic field lines reconnected (visible at the top of the coronal loops in these YouTube-movies AIA171 and AIA304) and on the solar surface where some material rained down (GONG-images underneath). This gave a complex evolution of the hot parts of this flare, at times making it look like a candle flame (upper right image; SDO at 16:00UT).
This shape makes one think of cusps (image lower right; Yohkoh-image from 07 June 2000). UPDATE: Initially I thought this was not a cusp, because today's structure seemed to be built up of several fine coronal loops, whereas a cusp is really a solid shape filled with plasma from the eruption (more on cusps at Yohkoh's "Science nuggets" via "Hot Topics"/LMSAL). However, the x-ray-images (just like Yohkoh's, not EUV like SDO's) of GOES-15's SXI show much better the cusp-like features of this post flare structure. See for example this SXI-image made 20 January at 23:56UT.
Also impressive are the highly helical dynamics of the ejected filament material, as can be seen in this multicolor movie made by SDO (Solarsoft). Initial analysis (SIDC, NOAA) indicates Earth may be hit by the CME late on 21 January. The flare also enhanced proton levels, but the treshold has not been reached. (updated at 21 January at 13:00UT).
The southern part of the region's filament was not ejected. Moreover, the rest of the filament seems to be reshaping itself (see latest GONG-images). Hence, more energetic flares may be produced in the coming days and these may again be Earth directed as NOAA 1402 transits the central solar meridian.

UPDATE: I added another movie on YouTube, this time combining SDO-images in the wavelengths of 4500Å (photosphere; 6000K), 171Å (upper transition region; 650000K) and 335Å (lower corona; 2,5 million K). This clip shows well the position of the eruption and the post coronal loops relative to NOAA 1402's main spot. Note how one end of these loops seems to be anchored above the region's main (big) spot. The movie is best viewed in half-screen or at the website of Helioviewer (link in description box).

04 January 2012 - I've uploaded 2 more movies on YouTube:

Additional details are in the movie's description box.

25 December 2011 - There has been quite some solar activity over the last 48 hours, in particular some really great prominence and filament eruptions. Based on images from the SDO-satellite and the GONG H-alpha Network, I've created 2 YouTube-movies showing the events in the red 304A and in H-alpha. Comments were added to the videos. The H-alpha movie does not cover the third event (24 December prominence eruption at the NW-solar edge) due to a rare gap in the H-alpha series, but its evolution was nicely captured by Guido Gubbels from the Belgian Solar Section. Update: Beautiful movie of the same event by Rogerio Marcon.

03 December 2011 - The provisional SIDC SSN for November is 96,7. This continues the positive trend in solar activity that started this summer. As can be seen from an earlier statistical prediction, these values are within line for a moderate maximum SSN of 83. Because this maximum is expected to be still a few months out (second half of 2012 at the earliest), it is expected the maximum will rather be in the upper half of the uncertainty band (so between 83 and 101). This is also in line with earlier predictions by the NASA/NOAA WG (90 +/- 20). Certainly no Dalton-minimum is in the offing.

Graph underneath also shows the increase in medium (M) and strong (X) solar flares. So far, there have been 126 M- and 8 X-flares for SC24, with the majority produced over the last few months. The table shows the most flare-prone sunspot groups, ranked according to the total fluence (power of the flares). For a predicted SC24-maximum of 83, over 700 M-flares and about 100 X-flares can be expected. There have also been 8 small proton flares so far. The last one was produced on 26 November and had a geometry very similar to another (non-proton) event on 30 November. See the GONG-website for H-alpha movies of these events (resp. Udaipur, Big Bear).

The increased solar activity also brought us the first 2 supergroups of SC24 (see my 2004-research for more info on big, super and giant sunspot groups). Some characteristics and images of these groups and the 3 big groups can be found in table underneath. No giant groups so far, but even for this moderate cycle a few can be expected.

More on sunspot generation, sunspot activity prediction, and the current state-of-affairs in SC24 can be found in the presentation I gave last week om MIRA Public Observatory. Please allow some time for upload, as the presentation is about 30MB, and the accompanying zip-file with all the movies is 533MB. Thanks to Philippe Mollet for hosting these files on his website.

15 October 2011 - Applying the McIntosh-classification on sunspotgroups - There were quite a few sunspotgroups visible today. Using the McIntosh-classification, one might get an idea of the flare-production in the next 24 or 48 hours. Experienced organizations like NOAA or STAR provide on a daily basis the classification of the visible sunspotgroups, thus giving an idea to the solar and spaceweather community on the imminent solar activity for that day. However, for many years now, NOAA is known to make blatant errors in their classification. STAR provided a welcome check on the NOAA reports, until they started using the very big SDO-images (4096 and 2048). Not only the classifications are indicating too much activity, groups which are too small (actually pores) are also counted into the sunspotnumber.

As an example, NOAA and STAR-classifications (both made about 8 hours before my own) were put together unto one map with my visual observations (Celestron 8", 68x, Thousand Oaks ObF, blue OcF). The map used is the 512 SDO-image just a few minutes before my own observation, and represents very well what I saw with reasonable seeing (see image with the classifications above). 3 small groups that were only seen by STAR (2 near NOAA 1319 and one near NOAA 1309) were not indicated on the map, to avoid overflow.

As one can see, major differences exist in NOAA 1312, 1313, 1316 and 1319.

Because of this overestimation of the sunspot-classification, this also gives a wrong idea of the possible solar flare acivity. Table underneath gives for today and for NOAA, STAR and myself the number of groups, the sunspotnumber (SSN), the Classification Value (Malde) and the expected number of M- and X-flares according to Kildahl (Bornmann and Shaw). So, I predict for today just a few C-flares from the main regions, with only a remote chance on an M-flare. NOAA expects for today 1 M-flare (with a remote chance on zero or two M-flares), and STAR expects between 1 and 3 M-flares.

ObsgroupsSSNCV (Malde)MX (Kildahl)
NOAA101572311,05 +/-0,87
STAR142682112,26 +/-0,87
JanJ91211460,48 +/-0,80

01 October 2011 - Between 08:00 and 10:00UT this morning, some interesting solar activity could be observed in Ha. The first hour, a few prominence eruptions and surges took place at the northwestern limb near NOAA 1301. This sunspotgroup was either spotless (bright faculae field) or located behind the limb, and the activity did not leave much of an X-ray signature. Meanwhile, some restructuring was taking place in the northern filament portion of NOAA 1302. This resulted at around 09:00UT in a dark filament eruption and surge, followed by a C2,7-flare (maximum at 09:10UT). The expulsed material could be seen flying over the sun's limb starting around 09:25UT, with the brightest parts remaining visible in Ha until 09:46UT at an est. 140000 km above the solar limb. This CME came after some material ejected by another surge in NOAA 1301 at 09:20UT. They could be distinguished from each other by the slightly different ejection angle, and NOAA 1302's was a little wider. Meanwhile, an eruption was already taking place in the northern part of NOAA 1305, peaking at 09:39UT (C5.9). It was followed by an M1,2-eruption (1B) in the southern part of this sunspot region peaking at 11:59UT. The maximum brightness in H-alpha was reached well in advance of this maximum X-ray brightness (11 minutes). In the movie from the GONG Ha-Network, a Moreton wave can be seen heading southward. It seems the wave originated during the transition from the northern to the southern flare-phase.

The image underneath shows the solar surface and surroundings at 09:29UT as could be observed in 30.4 nm (SDO) and in Ha (GONG/El Teide). It shows the

The X-ray-evolution of these events can be seen in the GOES15-X-ray-image underneath. As could be expected, NOAA considered the three eruptions as 1 event, which probably is OK for the two eruptions in NOAA 1305, but certainly not for the preceding event in NOAA 1302.

245 September 2011 - In view of this month's flurry of high-energetic solar flares, table underneath summarizes the Top-10 11 12 13 of the most powerful flares during Solar Cycle 24 so far. The flares are ranked according to their peak X-ray strength. The list was compiled from SIDC-reports, the daily SWPC-summaries and NOAA's "The Weekly". Please consult these documents for further information on the parameters used. Images and movies can be found on, GONG H-alpha Network, SDO and SOHO.

NOAA 1302 is visible with the naked eye and the biggest sunspotgroup of SC24 so far. With its mixed magnetic polarities in the middle portion, it continues to be a potential source of high-energetic flares. As NOAA 1302 rotates further on to the solar disk, its eruptions may become more geo-effective.

TimingX-rayProton (pfu)Radio (sfu)HaLocationNOAAMcIntoshArea (MH)CMESpeed (km/s)Transitap/kp
09/08:05 Aug 11 X6,9 26 710 2B N17W69 1263 Ekc 450 Yes 1000 - -
15/01:56 Feb 11 X2,2 Enhanced 1300 - S--W-- 1158 Ekc 450 Yes - 71h40m 48/5
06/22:20 Sep 11 X2,1 Enhanced 740 2B N14W18 1283 Eai 200 Halo 800 62h23m 67/6
24/09:40 Sep 11 X1,9 TBD 660 2B N12E60 1302 Ekc 840 Yes 400 TBD TBD
07/22:38 Sep 11 X1,8 - 1300 3B N14W28 1283 Dai 230 Halo 541 38h12m 67/6
09/23:23 Mar 11 X1,5 - - 2B N08W09 1166 Ekc 630 No - - -
22/11:01 Sep 11 X1,4 TBD 970 2N N13E78 1302 Eki 480 Yes 1392 TBD TBD
04/03:57 Aug 11 M9,3 96 720 2B N19W36 1261 Dki 300 Halo 1500 41h58m 179/8
30/02:09 Jul 11 M9,3 - 180 SF N--E-- 1261 Dai 300 No - - -
12/11:26 Feb 10 M8,3 - 350 SN N26E11 1046 Eac 190 Partial 550 79h06m 32/4
25/04:50 Sep 11 M7,4 TBD 150 2N N11E47 1302 Fkc 1300 Yes - TBD TBD
24/13:20 Sep 11 M7,1 TBD 12000 - N--E-- 1302 Ekc 840 Partial 1050 TBD TBD
08/15:46 Sep 11 M6,7 - 91 1N N14W40 1283 Cao 200 No - - -

23 September 2011 - Some results of research in the domains of solar physics and geomagnetism: Ultrafast substorms explained, The secret lives of solar flares (also at Sky&Telescope), New method detects sunspotgroups before they are visible (also at PhysOrg_com), Wave power can drive sun's intense heat.

10 September 2011 - The Solar Cycle 24 Tracking Page and the page with the most energetic flares since 1976 have been updated.

08 September 2011 - From 19 to 23 September 2011, a very important meeting on the calibration of the sunspotnumber will take place at Sunspot, New Mexico, USA. Today's heavyweights in the observation and determining of the sunspotnumber will discuss a variety of topics in order to get numbers that are truly and reliably comparable on the timescale of several hundreds of years. The issue was summarized very well by Leif Svalgaard in his 06 July talk in Melbourne, Australia. Aside Leif, the workshop will also be attended by Ken Schatten, Frederic Clette, Peter Foukal, Thomas Friedli, David Hathaway and Bill Livingston, amongst prominent others. The program can be found here. A follow-up workshop is planned in Europe next year. Needless to say a lot of work is going to be involved in this, but the potential outcome might have far-reaching consequences in all areas related to the observing of sunspots and the determining of the sunspotnumber. To be continued!...

07 September 2011 - Yesterday morning at 01:50UT, NOAA 1283 produced a high-energetic M5,3-flare (H-alpha class 1B). At 22:20UT, it produced an even more powerful X2,1-flare (2B). Both flares resulted in a proton enhancement, but the event treshold was not reached. NOAA 1283 is not a big group, but it does have opposite magnetic polarity spots close to each other. At this moment, this configuration is still there, but the spots are more separated from each other. Major flares remain possible. SIDC reported each flare was associated with a halo CME. However, since they are both directed north of the ecliptic plane, only a glancing blow is expected and not before midday of 09 September. Movies of the events can be found at Solarsoft and GONG H-alpha Network (Mauna Loa "Mh"; see image underneath).

05 September 2011 - The Spotless Days Page was updated. There have been 817 spotless days so far, with 14 August 2011 the most recent one (preliminary SIDC-report for August). This is not an unusual occurence at this stage of a moderate to low-amplitude solar cycle.

Lately, there has been some interesting activity from NOAA 1280 at the northwestern solar limb. The region developed quickly since saturday (SDO, Solar Monitor), and a Mount Wilson drawing (03 Sep 11) showed opposite magnetic polarity spots in close proximity of each other (mind foreshortening effect!). Several M-flares were the result as the group started its backside transit. Fortunately, we have STEREO to follow its activity. A case of "What goes around, comes around..."?

Courtesy of the SDO(NASA) and the HMI Consortium, and the Kanzelhöhe Solar Observatory (CESAR).
Delicate coronal loops can be seen hovering over the flaring region in AIA171 (left) and H-alpha (right) at 07:08UT.

19 August 2011 - Stereo-A tracks December 2008 Coronal Mass Ejection from Sun all the way to the Earth - Some very nice movies on how a CME evolves on its way from the Sun to the Earth are provided by Stereo-A. This satellite was about 45° ahead of the Earth and thus had a really good view of the Sun-Earth line at that time. An explaining clip by GSFC can be found underneath and more movies describe the details of the entire happening (WUWT, Science-at-Nasa, Universe Today). Though it is certainly not the first time the Stereo-satellites tracked CME's from the Sun to the Earth (see Stereo panorama, CME has croissant shape and RAS), it's the new image processing technique that provides unprecedented views of the evolving CME on its route to Earth.

Courtesy of NASA/GSFC

09 August 2011 - X6,9-flare in NOAA 1263 - Earlier this morning, the strongest solar flare so far in SC24 took place in NOAA 1263. The explosion occurred at 08:05UT near the "middle" portion of this complex group, where negative magnetic polarity from a new region met the positive polarity of the trailing spots of the original NOAA 1263. This location caught the immediate attention already 2 days ago, when the two fluxes bumped into each other. Initially, black polarity was to the north of the trailing spot, and did not give rise to much flare activity as the spots remained a bit separated from each other. Yesterday, black polarity also engulfed the southern portion of the trailing spot, producing an M3,5-flare (with proton-enhancement) at 18:10UT yesterday evening and a M2,5-flare at 03:54UT earlier this morning. Both events occurred on the southside of the "middle" spot and got H-alpha class 1B. The X6,9-flare covered the entire area (H-alpha class "3B" from my own observations; 2B according to NOAA), so both north and south of the trailing spot (see images underneath from SDO (visual and magnetograms) and the GONG H-alpha Network). The event is also a proton-flare and still in progress. The most recent SDO-movies show the opposite polarity spots are still very close to each other. Further energetic events remain possible.

Courtesy of the SDO(NASA) and the HMI Consortium, and the NSO/GONG H-alpha Network Monitor

07 August 2011 - There exists a real possibility on a major eruption in NOAA 1263 as the leading portion (negative "black" magnetic polarity) of a newly developing region is bumping into the trailing portion (positive "white" polarity) of the original NOAA 1263. If the spots come within less than 2,5° of each other (and are strong enough), an M- or even low X-flare could be produced in the next 24 hours. There is no reason to classify these regions (NOAA 1263 and the "new" region) separately, as they are within less than 10 degrees in longitude of each other. It's good to know though what's going on, so that the possibility on a major eruption can well be estimated. Movies at and SDO (magnetogram).

06 August 2011 - Update on geomagnetic storm - The geomagnetic storm seems to be gradually subsiding. Maximum Kp of 8 was reached yesterday during the 18:00-21:00UT interval. Per subsequent 3-hour-interval, Kp then went down by 1 point. The latest geophysical alert message from NOAA/SWPC states the storm reached G3-levels (NOAA-scales). According to, aurorae were seen in Europe as far south as England, nothern Germany, Poland and the Netherlands, and for the United States Colorado and Nebraska. NOAA's latest Report of Solar-Geophysical Activity merits close reading (my comments are highlighted):

...IIA. Geophysical Activity Summary 04/2100Z to 05/2100Z: ... From 1800-2100Z, minor to severe storm levels dominated. Solar wind data from ACE showed a shock-like feature passing ACE at 04/2105Z which was followed by a 20 nT sudden impulse at 04/2155Z. ... An additional shock passage was seen at ACE at 1722Z followed by a noticeable increase in solar wind density, velocity and magnetic field. An additional enhancement in the solar wind parameters was observed at 1834Z which include Bz fluctuation to -20 nT. Although the interpretation is not yet certain, timing analysis and model simulation suggest that the 1722Z & 1834Z enhancements are the first two of the three expected CME passages. (So, the 04 August disturbance seems unrelated to the 02 August CME, and the third CME might still be underway). GOES 15 observed magnetopause crossings between 1900Z-1915Z and 2000Z-2030Z. GOES 13 also observed magnetopause crossings between 2000Z-2030Z. (see plot below!)

The last similar geomagnetic storms date already back from 05 April 2010 (Combination of NOAA 1059 and coronal hole; Kp "only" 7) and then already from 14-15 December 2006 (NOAA 0930; Kp-index of 8 for 9 hours!). A Kp-index of 9 dates already back from 11 September 2005 (NOAA 0808). With its geomagnetic latitude of 45°, this is in principle the Kp-value needed for aurorae being visible from Belgium.

05 August 2011 - Major geomagnetic storm in progress - The second CME passed ACE at around 17:00UT this afternoon, and started to influence the geomagnetic environment shortly before 18:00UT. Solar wind speed jumped from 400 to 600 km/s. Similar to the first CME (which arrived yesterday evening around 22:00UT), this is a considerable slow-down compared to its solar lift-off speed of over 1100 km/s. However, this time the impact is much more pronounced as Bz (the vertical component of the interplanetary magnetic field) turned strongly southward. With currently sustained levels of -20 nT, this is indeed twice yesterday's value. The Kp-index for the period 18:00-21:00UT was 8, which corresponds to a severe storm (G2 or possibly G3: see geomagnetic NOAA-scale for effects). Auroral activity, as measured by POES, continues to increase as Bz has remained strongly negative over the last two hours. Over the last hour (21:00-22:00UT), the auroral activity level jumped from 6 to 10. Weather permitting and if Bz remains southwardly oriented, aurorae could be visible down to northern England. also reports that the CME has pushed the magnetopause close to geosynchronous orbits, thus exposing satellites at these heights directly to the solar wind.

Earth's space environment can be monitored on ACE and at SWPC.

As modellers from the GSFC Space Weather Lab have been calculating, it is very likely this CME is the combination of the CME's from 03 and 04 August. Solar wind data will provide the answer in the next couple of hours.

04 August 2011 - In view of the ongoing solar activity, table underneath summarizes for each of the 3 big groups per day their McIntosh-classification, the number of C- and M-flares and the strength of the strongest flare produced (See this presentation for the different types of solar flares). The McIntosh-classification was determined using HMI-Intensitygrams (1024-resolution) taken by SDO, usually at around 05:50UT that day. The flare-data are from NOAA/SWPC's "Event reports". Today's flare numbers are still preliminary.

As the SIDC pointed out in their latest Presto Alert, the energy of the NOAA 1261 eruptions seems to be increasing. This is not only visible in the flare strength (M1, M6 and M9 on resp. 2, 3 and 4 August), but also in the speed of the CME's (resp. about 800, 1100 and 1200 km/s) and the increase in proton level (after 2 proton "enhancements", the M9-flare produced a proton event, probably also because the region is now more westward). In view of today's simplified structure of the group, even more energetic events are not expected.

The CME's are expected to reach Earth late 04 or early 05 August. In view of the speed differences, it is not unlikely that the CME of the latest M9-flare will catch up with the CME's of the earlier two CME's before they reach Earth, which might lead to a complex and -pending the north-south magnetic orientation of the CME- severe geomagnetic disturbance. Because in each of the three flares, north (white; "coming out") was on top of south (black; "going in") polarity spots, it is not unlikely that this orientation is also embedded in the CME's, thus favoring a north-south ("negative") orientation, hence severe geomagnetic disturbances. Earth's space environment can be monitored on ACE and at SWPC.

Finally, as the three regions approach the western solar limb, and if they continue to show flaring activity, it is very well possible to get some really spectacular prominence eruptions in the next few days.

DayNOAA 1260NOAA 1261NOAA 1263Day
25 Jul 11Bxo00---------25 Jul 11
26 Jul 11Dao20C 3Hhx00-----26 Jul 11
27 Jul 11Esi71M 1Dko00-----27 Jul 11
28 Jul 11Eai90C 5Dko10C 1Dho00-28 Jul 11
29 Jul 11Esi20C 4Dki100C 6Dhi10C 129 Jul 11
30 Jul 11Dho00-Dki01M 9Dhi00-30 Jul 11
31 Jul 11Dho00-Dai20C 3Dho40C 131 Jul 11
01 Aug 11Dho00-Dkc40C 4Dho10C 201 Aug 11
02 Aug 11Dho00-Dkc21M 1Dko20C 202 Aug 11
03 Aug 11Cho00-Dkc 142M 6Dkc11M 103 Aug 11
04 Aug 11Hhx00-Dao41M 9 2Dhc00-04 Aug 11
1: Dko? Clearly transforming from "compact" (02 Aug 11) to "open" (04 Aug)
2: Proton-flare

01 August 2011 - With the preliminary SIDC-sunspotnumbers and the improved Bendel-Staps SSN25-formula, one can calculate a new value for the SC24-amplitude. The preliminary smoothed sunspotnumber (SSN) for January 2011 being 30,27, a SC24-maximum of 83 +/- 18 is predicted. This is slightly up from an earlier prediction (78 +/- 20) based on the rate of increase 19-20 months after solar cycle minimum (see Headline of 05 March 11).

Figure underneath shows the monthly sunspotnumbers (SIDC) and the predicted values based on Rmax = 83, and an uncertainty of 18. The curves were calculated using Hathaway's method. The obtained values again seem to exclude Dalton-like or average amplitudes. Rather, they seem to hint to a maximum similar to those in the late 19th - early 20th century (SC12, 13). The maximum is expected in May 2013, with an uncertainty of 10 months.

A word of caution: This is a statistical approach, meaning that uncertainties both in amplitude and in timing can deviate significantly from the predicted values, even at this stage of the cycle!

The next key-moment in this statistical follow-up of the evolution of SC24 will be when the smoothed SSN reaches 50. According to the Waldmeier laws, this happens about 23 months (+/- 8 months) before the SC reaches its maximum. In view of the monthly sunspotnumbers we had lately, this could be happening right now... More early next year, when the smoothed numbers will come in.

01 August 2011 - Triumvirate of major sunspotgroups rules the (northern) solar surface, as can be seen in the images underneath. The visual image and magnetogram were taken by SDO at 06:40UT this morning, the H-alpha image is from the Learmonth Observatory, Australia taken only 20 minutes later. Most flaring activity comes from NOAA 1261 (middle). That's certainly not the biggest group, but over the last few days, it has developed some magnetic intermixing with opposite magnetic polarity spots close to each other. This is not the case for big group 1263 (opposite fields with almost no such closely spaced spots) and quiet NOAA 1260 (right), which is just an open group without any magnetic intermixing at all. This difference can also be seen in H-alpha: NOAA 1261 is a lot brighter than NOAA 1263, whereas NOAA 1260 is not bright at all. Based on these observations, small M-flares from NOAA 1261 remain possible. NOAA 1263 has an outside chance in producing an M-flare, and NOAA 1260 has the potential for C-flares only. Using eclipse glasses, both NOAA 1261 and 1263 were naked eye objects this morning.

27 July 2011 - At last... some solar activity! Around 16:00UT this evening, NOAA 1260 has produced an M1-flare. Though consisting of only small spots, it has some magnetic polarity mixing which may herald further flare activity. NOAA 1261, despite being larger, has no such mixing and is -at this moment- very quiet. Live evolution of the flare activity can be followed at GONG (H-alpha), SWPC (X-ray) and SDO (visible and other wavelengths).

16 June 2011 - Significant findings in solar research - Over the last couple of weeks, some interesting scientific results in the domain of solar research have been announced. An overview.

07 June 2011 - At around 6 o'clock this morning, magnetic fields in NOAA 1226 became unstable and resulted in a medium M2,5-flare accompanied bij a spectacular CME and a still ongoing protonstorm. As usual, the event was captured in its entirety by SDO (See Spaceweather and SolarSoft for some stunning movies). Certainly watch the "difference-movies" showing how the CME is actually perforating the magnetic bubble around the blast side! It is clear, also from SOHO's Lasco-movies, that (the central) part of the CME is ejected. However, another part of the CME is falling back over an unusually wide area along the magnetic field lines to the solar surface as in a round fountain (dark material in the AIA-movies), and in some places causes a modest brightening (see Science-at-Nasa for more peculiarities on plasma rain).

The Sun Today made some very useful commentaries to what there actually can be seen (see movie underneath).

The spectacular event was also observed by Proba2 (SWAP) in EUV, and also by the GONG-network that caught the entire event... in H-alpha. In particular today's Udaipur-H-alpha movie is really fascinating! Also Cesar had a good look on the flare.

The SIDC's assessment indicates a CME-speed of 1000 km/s, and expects -in view of the large spatial extent- a geomagnetic disturbance on June, 9th. The severity of the impact will depend on the north-south-orientation of the arriving particle cloud.

Finally, it is to be noted that today's blast originated in the same area as the June, 1st C4-flare. That event was also accompanied by a CME that -together with a similar event in NOAA 1227 on June, 2nd- caused geomagnetic disturbances on 04-05 June with aurorae visible in Canada and northern US.

UPDATE - Some magnificent movies of this event were uploaded at NASA's Multimedia Videogallery (movies from 01 and 11 July 2011).

Courtesy of The Sun Today

02 June 2011 - The filament complex currently showing in the northern hemisphere looks a lot like the one late july 2010 that caused an impressive "global" eruption on the sun. It's actually not too far from the same location too (only about 40-60° more to the east). Interesting to see what's going to happen this time.

Meanwhile, the filament in between NOAA 1227 and 1226 that disappeared after today's spectacular eruption (C3-flare with H-alpha class 2N!), is starting to reestablish itself. Magnetograms show NOAA 1227 is not a bipolar group, but 2 separate groups. Of course, visual observations prevail! NOAA 1226 is currently a loose pile of sunspots. At the moment, it seems to have gained some more sunspots and area coverage. Also curious here to see how that one is going to evolve: 1 complex group or 2 separate groups (or maybe both...)?

29 April 2011 - In view of the sudden increase in sunspotnumber as observed during the month of March 2011, I added an article to the Solar Cycle Page entitled "Extreme changes and quiet spells in monthly sunspotnumbers". As can already be seen in the graph underneath, the March-increase was important, but -for the same sunspotnumber- more important increases have been seen in the past.

21 March 2011 - There's currently a proton enhancement ongoing, without any noticeable flare of filament eruption preceding it. It also got nothing to do with the impressive prominence that was visible at the southwestern solar limb last saturday. From today's SIDC-bulletin:

The proton flux measured by GOES13 increased this morning. The storm threshold is not reached. We don't expect the threshold to be passed. A back sided plasma cloud came into view of STEREO B COR2 at 02:54UT, March 21, 2011. This CME is probably associated with the increased proton levels. The Earth is magnetically connected with the source site behind the Sun. The Parker spiral has bended magnetic field lines that guide the electrically charged protons. The Earth is near such field lines along which these protons travel. This is a rare event.
UPDATE: A long duration C-flare took place on March 21. The source region is located in the west: Cat 35/AR 1176. A CME was ejected. The CME is not earth directed. We expect more flaring activity from this group. This event probably pushed the >=10 MeV proton flux to a higher level, the curve passed slightly and for only a short time the storm threshold. The flux level is at the moment still elevated.

The Stereo A-movie (04:00UT) seems to show coronal loops forming above NOAA-region 1169, which was also at the origin of a mild proton enhanced event last week, followed by the flare/CME as can be seen in the Stereo B-movie. Really amazing how a region at the sun's backside can still significantly affect earth's spaceweather. For the Stereo B-event to have any influence on the proton flux, it would require a very special Parker spiral shape though.

Meanwhile, old active regions 1164 (N) and 1165 (S) are about to cross the eastern limb for a "rerun". GOES- and SDO-imagery seem to indicate that these regions are still bright and active, showing large coronal loops. They merit close monitoring.

17 March 2011 - Very nice movies of yesterday's long duration (5h32m!) C3-flare in NOAA1169, which produced an impressive CME and mild proton enhancement, can be found at Spaceweather, Solarsoft, (1, 2), NSO, or you can create your own movies at SDO (time frame suggestion from yesterday noon till today noon) or at SOHO's Movie Theater. A slight coronal disturbance, probably due to magnetic restructuring above NOAA1169, can be seen just before the flare and beautiful coronal loops set in.

10 March 2011 - The sun strikes again! - Only a few weeks after having unleashed the first X-class flare of SC24, the Sun produced an impulsive (short-lived) X1,5-flare on 09 March peaking at 23:23UT. Originating in complex region NOAA 1166, movies of the event clearly show the eruption was preceded by a disappearing filament near region 1169. This disappearance was probably the consequence of the C9,4-flare about an hour earlier in the trailing part of NOAA 1166.

Cut-outs underneath (running difference from AIA304Å movie) show the action in and around NOAA1166 and 1169. The first and second image show the plasma moving back in a very fine tube (indicated by parallel arrow) towards NOAA 1166. The crashing into the trailing part of NOAA 1166 may have caused additional magnetic instability and subsequent eruption in the middle portion of the group. The 3rd image show the beginning of the disappearing filament near NOAA 1169, while the 4th image adds the flare in region 1166. The last image shows the remainder of the erupted filament drifting by north-east of the fading blast site. has stated that the SOHO's C2-images show no signs of a bright CME (my emphasis).

Screen-shots from the SDO/AIA 304Å-movie (running difference) of the event in and around NOAA regions 1166 and 1169.
Courtesy of SDO (NASA) and the AIA consortium

To really appreciate the complexity of the events, one has to take into account the must-see H-alpha movies made by Thomas Ashcraft.

One can also consult the H-alpha movies made at NSO or BBSO. The combination of these truly impressive movies and animations do justice to the complexity of this remarkable chain of events.

07 March 2011 - UPDATE: Eruption of NOAA 1164's canopy - Around 20:00UT this evening, the arches hovering over NOAA 1164 have become instable and erupted. This resulted in a M3,7-flare (20:12UT) as can be seen in this SDO/AIA304Å-movie, showing plasma raining down on the much denser inner solar atmosphere. See the LMSAL Solarsoft website for movies of the entire event. The stunning images underneath are screenshots from these movies (notice 3 different events, to show today's changes in the canopy), and the overall solar image comes from the SDO-website (AIA304Å, 19:59UT). This event is entirely different from today's M2-CME-event in NOAA 1166.

Update: A proton event is still in progress. The CME had the impressive speed of 2200 km/s (, NRL). As predicted by SIDC, the cloud hit STEREO-A in the late evening of March 9th, and delivered a few hours later what -at first sight- seems to be a glancing blow to Earth. The ongoing magnetic storm can be monitored via ACE-instruments and via the SWPC-site.

Screen-shots of three different eruptive events over NOAA 1164, showing today's evolution of the canopy from a pretty solid "ceiling" via a more ragged and bulged structure to an unstable and erupting prominence.
Courtesy of SDO (NASA) and the AIA consortium

Cut-out of SDO/AIA 304Å-image (19:59UT), showing the towering eruptive prominence above NOAA 1164. Estimated height at the time is over 400.000 km, that is 10 times earth's circumference.
Courtesy of SDO (NASA) and the AIA consortium

07 March 2011 - Solar flares hidden in the X-ray background - During this morning's observation session (09:15 - 10:55UT) with a modest PST, no less than 6 flares were observed in H-alpha. However, comparing with today's SWPC event listing, only 2 events seemed to have occured during that timeframe. What's going on?

Picture underneath shows the X-ray evolution as measured by GOES-15. The M1,8-flare at 09:20UT and C4,9-flare at 10:21 can clearly be distinguished. SWPC correctly attributed these flares to NOAA 1164. In my opinion, Solarsoft mistakingly attributed the M1,8-flare to NOAA 1165, hence the corresponding movies show the wrong region. The observed eruptions are indicated on the Kanzelhöhe cut-out in yellow and green, and were labelled resp. 1 and 4.

The events 3 and 6 (blue numbering) occurred in NOAA 1165, at the same location as the M1,5-flare earlier that morning (see complete Kanzelhöhe image taken during the flare). Events 2 and 5 are indicated by resp. pink and red and were located north of the filament. These 4 events either had the bad luck to occur in the descending phase of a much more powerful flare (event 2: slight "shoulder" in X-ray flux), or too short lived (events 5 and 6; see SWPC's User Guide page 5), or both (event 3).

An overview of the observed eruptions (timings are those of maximum brightness):

Finally, there are a couple of very nice movies of today's M1,2-flare in NOAA 1164 at LMSAL's Solarsoft. AIA171 and especially AIA304 show some great dynamics in the canopy overarching the sunspot region. More energetic flares in the regions 1164, 1165 and 1166 can be expected.

05 March 2011 - With the preliminary SIDC-sunspotnumbers and the improved Bendel-Staps v20-formula, one can calculate a value for the SC24-amplitude. The rise of the smoothed sunspotnumber between July and August 2010 being 1,07, a SC24-maximum of 78 +/- 20 is predicted. The R25-formula can not yet be used (early August this year), but current estimates result in a maximum in the low 70's, with a slightly smaller uncertainty.

Figure underneath shows the monthly sunspotnumbers (SIDC) and the predicted values based on Rmax=75, and an uncertainty of 20. The curves were calculated using Hathaway's method, time-adjusted to better fit the Waldmeier law (page 2), and finally Meeus smoothed. The obtained values seem to exclude Dalton-like or average amplitudes. Rather, they seem to hint to a maximum similar to those in the late 19th - early 20th century. The maximum is expected in August 2014, with an uncertainty of 16 months.

A word of caution: This is a statistical approach, meaning that uncertainties both in amplitude and in timing can deviate significantly from the predicted values, even at this stage of the cycle!

02 March 2011 - There was an interesting teleconference today on the most recent solar cycle minimum and the missing sunspots. Supporting material is at NASA's Sunearth website, a more general article is at NASA's Science News. Nandy et al. have developed a model, building on 4 other models (see slide cut-out underneath), that can recreate the past solar cycle minimum which was unusually deep and long. They found that the poleward meridional circulation was fast in the first half of SC23, and slow in the second half. The fast movement causes a weak polar field and prevents magnetic field strengthening in the solar interior, whereas the subsequent slow movement delays the onset of the new cycle (and thus a lot of spotless days). Thus, by studying the internal motion of the meridional circulation, one could predict deep and long minima, and thus the related terrestrial spaceweather impacts. Particulary impressive was that their model showed very well the detail observed in the evolution in the surface magnetic field during the solar cycle (see bottom right of slide cut-out). Only the graininess of the local sunspot magnetic fields is missing.

In the Q&A session afterwards, a journalist asked if their observations are not contradictory to the work of other solar scientists. Nandy responded that their work is supported by observational evidence such as Howe and Hill (2009). Differences with work by other researchers such as Hathaway (2010) may be explained by the fact that the new model also takes into account the movement of magnetic field elements due to magnetic scattering, not only the meridional circulation. They showed, in my opinion, a healthy scientific spirit by not claiming that theirs was the overall truth, but by looking forward to further discussions with fellow scientists to refine the models.

There was no mentioning of the Livingston-Penn effect or Schatten's percolation theory (Hinode movie), and no prediction was made for the maximum of ongoing SC24. Also no reason/cause was given for the variability of the meridional circulation. Discussion is ongoing on the WUWT-site (here and here). David Hathaway also responded directly tot the author's article at the Nature website. Clearly, the last word on the missing sunspots hasn't been said yet!

24 February 2011 - Peaking at 0735 UT this morning, a region still behind the NE solar limb produced a M3,5 flare. There's a nice SDO/AIA picture of the subsequent CME at Spaceweather, but also a truly impressive movie made by the Proba2-satellite. Notice the magnetic restructuring in the coronal loops after the flare and CME took place. The CME is directed away from Earth and should have no impact. Of course, the active region merits full attention once it gets around the limb.

Update: More great (and detailed) movies of this event are at Spaceweather, YouTube, and LMSAL's Solarsoft. This are all movies made by SDO's instruments. In particular the running difference movies are quite stunning (like this AIA 211 movie). The event was also SOHO's Pick of the Week. The M3,5-flare really seems to be caused by relatively tiny region NOAA 1163.

The CME from last week's X2-flare did not produce a big geomagnetic storm, because its strong magnetic field was oriented north (positive, opposite to earth's magnetic field). It did cause a moderate Forbush-decrease though, as can be seen in this picture made by the Oulu neutron monitor.

15 February 2011 - First X-class flare of SC24 - At 01:56UT this morning, NOAA 1158 produced the first X-class flare of the ongoing solar cycle. According to the SIDC, this X2,2-flare was accompanied by a CME (movie at Spaceweather) which is expected to reach Earth by 17 Feb 11. There is also a mild proton enhancement ongoing, but it does not seem to reach the event treshold. SDO-movies of the event are at LMSAL's Solarsoft. There is also a very impressive movie of an EUVI-wave expanding from the blast site (see screenshot underneath). NOAA 1158 may further produce high energetic flares.

Table underneath shows the 10 longest periods (since 1976) without an X-flare. With today's X2,2-flare, a new record was set. Indeed, there were 1524 days since the previous flare on 14 Dec 06, making it almost a half year longer than the previous record period. The current solar cycle transit also holds the records for longest period without C- or M-class flare (see table). The last more powerful flare than today's dates back from 13 Dec 06, also produced by NOAA 0930 (X3,4).

Update (22 April 2011) - Rotating sunspots spin up a super solar flare.

Screenshot from the SDO 304Å-movie only 3 minutes prior to maximum showing the parallel ribbon flare along the magnetic inversion line
Courtesy of SDO (NASA) and the AIA consortium

Screenshot from the SDO EUVI-wave difference movie
Movies courtesy Nariaki Nitta, Lockheed-Martin

1.14 Dec 06X1,5093015 Feb 11X2,211581524
2.03 Nov 92X9,0732109 Jul 96X2,679781344
3.06 Feb 86X1,7471102 Jan 88X1,48801695
4.30 Apr 76X2,0070007 Sep 77X2,00889495
5.09 Jul 96X2,6797804 Nov 97X2,18100482
6.15 Sep 05X1,1080805 Dec 06X9,00930446
7.24 Apr 85X1,9464704 Feb 86X3,04711286
8.06 Jun 83X1,4420117 Feb 84X2,34421256
9.28 Nov 98X3,3UNK 02 Aug 99X1,48647247
10.21 May 84X2,7449221 Jan 85X4,74617245

14 February 2011 - NOAA 1158 is displaying some very nice activity. The mixed polarity resulted in a M6,6 flare yesterday and a M2,2 just minutes ago. There are some great SDO-movies at LMSAL's Solarsoft page. Notice how the flare follows the magnetic inversion line. SIDC forecasts geomagnetic influence from the M6,6 flare's CME for 16 Feb 10.

So far, SC24 has produced only 4 High Energetic Flares (M5 or higher), the highest a M8,3-flare produced by NOAA 1046 on 12 Feb 10. With its current magnetic complexity and McIntosh-classification (Eac), there's a 14% chance on additional M-flares and (only) 2% chance on X-flares (if it doesn't become bigger or even more complex of course...).

Courtesy of SDO (NASA) and the AIA consortium

02 February 2011 - Over the last couple of weeks, I've been working to update the general solar cycle page. Amongst other, it features:

I also added a few words on the Gnevyshev-Ohl rule, which was apparently broken by SC23. The last time this happened was during the Dalton minimum about 200 years ago.

10 January 2011 - New insights into sun's photosphere reported - BBSO's 1,6 m solar telescope reveals "... that the Sun can generate magnetic fields not only as previously known in the convective zone but also on the near-surface layer". "We believe small-scale turbulent flows of less than 500 km to be the catalyst," said NJIT Research Professor Valentyna Abramenko at BBSO.

07 January 2011 - Plasma jets are prime suspect in solar mystery - New high-resolution images made by SDO and Hinode point to type II spicules as the most likely source of the hot solar corona. These 100 km/s rising jets deposit hot plasma into the corona before rapidly disappearing. The biggest challenge now is to understand what drives and heats the material in these spicules. So, the mystery is not solved yet, but the solar detectives gained one important clue! The lead author of the Science paper is the Belgian Dr. Bart De Pontieu at the Lockheed Martin Solar and Astrophysics Laboratory. Quick-time movies are available at Science/AAAS, containing additional information.

Screen shot from the S8-movie at Science/AAAS

14 December 2010 - 4 years without an X-flare! Today it is exactly 4 years since the Sun unleashed its last X-flare. Indeed, it was on 14 December 2006 that NOAA 0930 produced the last of its series of 4 powerful X-flares. The period of 1461 days beats the previous record of 1344 days that occured during the descending phase of SC22 (1992-1996). This table provides a comparison with other periods. Graph underneath depicts months with powerful flare activity.

12 November 2010 - Sun's magnetic building blocks revealed by Sunrise (Physorg). Some impressive movies of the Sunrise-launch and ending can be found at their website. Sunrise is a 1m-telescope with a 0,05" (100 km) resolution in visual, UV and magnetic at a working (balloon) altitude of 36 km taking high-cadence pictures for a couple of days uninterruptedly (8-14 June 2009).

06 November 2010 - NOAA 1112 is back as region 1121 and has produced already a few M-flares (e.g. M5,4 at 15:36UT; Solarsoft's SDO-movies). The region is not impressive from the sunspot point of view (in fact, the smallness of the sunspots is quite misleading), but the magnetograms clearly show intermixing in the trailing part of the region. Looking closely at the magnetogram, it almost looks as if the trailing part of one region is interacting with the preceding part of another region. Again, these reflections can only be based on the magnetograms, as neither in visual nor in the other wavelengths, there are indications for this. As long as this mixed polarity area exists, further M-flaring can be expected.

16 October 2010 - This animation shows NOAA 1112 and surroundings (southern solar hemisphere) in visual (SDO/HMI Intensity), H-alpha (Kanzelhöhe) and 193Å (SDO/AIA 193). The bright areas in H-alpha and 193Å correspond to NOAA 1112 sunspot region, while the filament is situated more southerly. Such long filaments may become unstable and result in a CME. Stunningly detailed movies of this area can be found at LMSAL/Solarsoft. The sunspot regions NOAA 1113 and 1115 are well visible in visual and H-alpha, but not in 193Å. Notice also the different outlook between the coronal hole and the filaments, and some of the H-alpha prominences are visible in 193Å. The images were made on 15 October between 12:15 and 12:45UT.

Update 17 October 10 - The mixed magnetic polarities in the small sunspots of NOAA 1112 have resulted in an impulsive M2,9 flare yesterday peaking at 19:12UT. The filament just south of this region was unaffected by this explosion, and seems to have grown in length.

26 September 2010 - Sunspotgroup or pore? - During the last 72 hours, some activity is going in a region about 15° west of NOAA 1109. There has been some discussion on whether or not this has to be classified as a sunspot group.

Certainly yesterday, it concerned only pores, as underneath cut-out of the highest-resolution intensity-image by SDO (08:11UT) clearly shows. Some observers didn't even see the pores with appreciable telescopes.

The difference between a pore and a spot has been explained in slides 32-34 in this SIDC-presentation.

The area does merit interest, because both on September, 24th as on today's SDO-images, a small speck can be seen. However, the big observatoria did not report a sunspot on the 24th, and it is unlikely that they will today, unless some new additional magnetic flux boosts those pores to real spots. The 06:00UT SDO-image shows again only a pore in this area. For the latest developments and images, see the SDO website.

Courtesy of SDO (NASA) and the HMI consortium

19 September 2010 - NOAA 1106 and the McIntosh-classification - Recently, solar observers have had a hard time in classifying NOAA 1106: Does this region concern 1 or 2 sunspot groups? If one considers this as 1 sunspotgroup, a very unusual sunspot classification emerges: Fsi (or Fso). Many observers choose the latter (and right) classification, because there were some very small sunspots between the two main spots that seems to be linking them, but it still remains a weird view. So, how unusual is this type of classification (Fso, Fsi, Fao, Fai)?

From my earlier study on the McIntosh-classification (The Big CV-project), an F-group on its own is already something quite rare: Of the 36530 McIntosh-classifications made between 1944 and 2009, only 737 (2%) were considered an F-group. Most of these were complex ("c") or had a big main spot ("h" or "k"). In total, only 84 classifications (0,2%!) were considered to be of the Fso-Fsi-Fao-Fai-type. Rare indeed! Underneath a few SOHO-images of SC23-groups with this type of classification (Fso, Fsi, Fao, Fai). Note that in both case, magnetic observations confirmed this was one sunspotgroup.

15 September 2010 - Livingston-Penn and the possibility of a new Little Ice Age - I was interviewed today by our national broadcast radio on the Livingston-Penn effect, and the possibility of a New Maunder-minimum and Little Ice Age. I avoided sensationalism, and used a lot of "if"'s. The audio is still available at the Radio-1 website (in Dutch).

16 August 2010 - Synoptic maps are updated - The page with synoptic maps (yearly) and contourmaps (over SC) has been updated.

Synoptic maps give an idea on how the activity is spread over the solar surface. This can be done by dividing the solar surface in areas of 10° longitude by 10° latitude. Then, over the course of a year, the total number of groups that appeared in each of these sectors is determined. As from 1996 onwards, they provide a yearly overview of the activity-spread concerning the number of groups, the activity areas (according to Waldmeier-classification), the sunspotarea, the number of M- and X-flares, and the flare-fluence.

14 August 2010 - First proton event of SC24 - Earlier today, NOAA 1093 released a modest C4-flare (Max at 10:05UT) which was accompanied by a CME and a proton event. This proton event is small, but it is the first of the new solar cycle (see NOAA/SWPC list).

The flare took place alongside the filament which can be seen on today's (07:03UT) Kanzelhöhe H-alpha image (at left). This filament stretches itself between NOAA 1093 and the quickly developing NOAA 1099. SDO's AIA304 image of 09:45UT (at right) shows the CME already departing (lower righthand corner; not the prominence at right!). SIDC (RWC Belgium) expects a small geomagnetic effect around 17 August. More SDO-movies of this event can be found at LMSAL's Solarsoft.

The proton event is still ongoing. Peak proton flux (+/- 12 pfu) seems to have been reached about 3,5 hours after the flare reached its maximum X-ray brightness (see diagrams; proton flux at right). This is consistent with a not very energetic event.

02 August 2010 - NOAA 1092 and disappearing filaments - Yesterday morning, the northern part of a filament twin erupted. The spectacular and complex event was recorded by SDO and Stereo. Stunning movies can be found at the websites of Spaceweather and LMSAL's Solarsoft (SDO, Stereo). Based on SOHO EIT 304-images and a Holloman report (SWPC), the southern part disappeared between 16:55 and 21:00UT. No movies are available (yet) of this event.

Some sites (Spaceweather, IPS) state a coincident C3-flare in NOAA 1092 was at the origin of the filament eruption, while others (SIDC, SWPC) merely noted the coincidence. From the SDO movies, in particular the AIA 304, it does seem that the filament is already erupting at around 07:15UT, more than 30' before the onset of the C3-flare (simply use the pause and play buttons). A shock wave does seem to ripple through the solar atmosphere after the C3-flare, but it arrives at the (northern) filament site well after the eruption's onset.

Interestingly enough, the C3-flare was preceded by a small B3-flare with maximum at around 06:55UT. It is unclear whether this flare originated in NOAA 1092, and if it was the cause of the filament eruption.

Due to the complexity and timing of the various filament eruptions and flaring events, the SIDC expects geomagnetic disturbances possible between late 02 Aug and 04 Aug. (Source: SIDC)

Meanwhile, NOAA 1092 is now a naked eye object, but it needs well trained eyes to see the barely visible speck. Also, in contrast to some classifications (SWPC, STAR), this really seems to be a "h" type group rather than a "k" type (according to the McIntosh-classification). The small irregularities in the umbra and penumbra of the main spot do not justify it to be classified as an asymmetric spot.

First analysis of this global solar event at Science at Nasa and additional movie at Universe Today (15 December 2010).

12 June 2010 - Active region NOAA 1081 - Earlier today, from a loose heap of small sunspots a.k.a. NOAA 1081 originated quite unexpectedly an M2-flare (00:57UT) and a C6,1-flare (09:17UT). Impressive movies of these events can be found at the SDO-website and especially at LMSAL's Solarsoft (M2, C6). According to the NOAA/SWPC, the M2-flare caused some proton-enhancement without reaching the treshold-level. The C6-flare was followed some 10 minutes later by an impressive mass ejection. Picture underneath is a screenshot from SDO's AIA 304 movie.

05 May 2010 - Proba-2 data now in near realtime online! - As announced by the SIDC yesterday, PROBA-2 data and images are now online. These images are indeed near realtime, but unfortunately, they are in fits-format. No problem though: the images can be viewed and toyed around with by simply downloading and installing SAOImageDS9, available for almost every operating system.

The results are quite impressive, as demonstrated by the image underneath, showing today's C8,8-flare in NOAA1069 at its maximum at 11:52UT. This region, at its high latitude of 42° has grown considerably over the last 24 hours and still has a mixed polarity. Hardly an hour ago, it not-surprizingly produced an M1,2-flare. And it seems more can be expected...

Update: Based on the Proba2-images, I've added a small movie of today's M1-flare. Images span from 17:07UT till 17:37UT, in lapses of about 2 to 5 minutes. Graininess and "moving around" of the image is courtesy of my clumsy moviemaking. Nonetheless, it can be seen that the magnetic field (arch) over NOAA1069 disappears during the flare (images 6 and 7), then gradually restructures and re-establishes itself in the course of about 15 minutes. The flare starts at 17:13UT (3rd image), reaches maximum at 17:19UT (5th image), and ends at 17:22UT (6th image).

04 May 2010 - 5 sunspotgroups today... - ...but they are all very small. According to one of today's SOHO-images, Sunspotnumber could be as high as 59 (5 groups, 9 spots). It remains to be seen if all these groups will be counted as sunspotgroups, due to the smallness of some. The final ISN for this day will probably be significantly lower (est. 25-40). A better index is the Classification Value (Malde, 1981), based on the McIntosh-Classification. With a value of 9 (2 Axx, 2 Bxo and 1 Bxi), this gives a much better idea of the true solar activity (= low!!).

The still to be numbered region on the high northern latitude is at an estimated +41°. This is the highest latitude for a SC24-region so far. It also produced a C3-flare this evening. Latitude nor flare-production are unusual for such a region. At the moment, it is the most prominent region on the solar surface, developping quickly and having some mixed polarity. Only NOAA1067 is also well visible, the other groups are fading or have faded away.

23 Apr 2010 - SDO's first light images and movies - Truly impressive clips at SDO's website, with explanations at the renewed Science-at-Nasa-website, and discussions at WUWT.

13 Apr 2010 - Prominence-whopper! - A large prominence erupted earlier today into a spectacular CME. Movies can be made at the SOHO Movie Theatre (simply click C2 or C3 and fill in today's date, i.e. 2010-04-13) or seen at Spaceweather.

Based on early H-alpha observations by André Gabriel, a renowned Belgian solar observer, and combining with C2- and C3-images from SOHO's coronographs (LASCO), the evolution in (radial) speed of the CME could be calculated. As can be seen, the speed of the CME is accelerating from about 20 km/s until it reaches a final speed of about 400-500 km/s, close to the solar wind speed. There's probably a spread of 50-100 km/s on the last couple of data points (2 of C2 and all of C3), due to resp. CME features becoming less bright and much smaller resolution in the C3-images. The data-points were based on a bright whisplike feature on the top of the inner CME-structure (notice the faint outlines of the outer CME in the above image). At around 08:45UT, the height of the CME in H-alpha was about 300000 km above the solar surface, but around 15:00UT, its distance had already increased to over 7 million km!

12 Apr 2010 - On solar flares... - Some interesting articles on solar flares appeared recently on the

05 Apr 2010 - Predicting SC24-maximum from early SC24-sunspotnumbers - Article

14 Mar 2010 - Solar Conveyor Belt - From Science at Nasa: Solar "Current of Fire" speeds up. The article also confirms 2006-reports of a very slow moving bottom of the conveyor belt (See Hathaway (2006)). Compare to:

Further comments and discussions at Anthony Watts' blog.

09 Feb 2010 - Disappearing filament - To the east of the active region NOAA 1045, part of a filament disappeared between 07 and 08 February. As can be seen in Kanzelhöhe's H-alpha images underneath, the filament snaked itself between regions of opposite magnetic polarity, but the southern part had disappeared by 08 February. It is interesting to note that this region is still visible in the SOHO's EIT and GOES14 SXI images as a dark river meandering between the regions of opposite polarity. Moreover, a spectacular loop developed itself above the northern part as can be seen in the EIT and SXI images. No conclusive material yet on the timing of the disapperance and whether the filament dissolved or erupted.

07 Feb 2010 - Fire in the hall!! NOAA 1045 has produced 3 M-flares overnight, one of which was a high-energetic M6. It was the first high-energetic flare (M5 or higher) since June 2007 (NOAA0960). More medium flares can be expected as long as there exists a mixed polarity in the sunspot group (see magnetogram underneath). The group seems to have grown into a McIntosh-class Eac. The chance on an X-class flare seems to be very small though (2%). Movies of the flares can be found at Solarsoft.

25 Jan 2010 - Interesting presentations on "Aspects and consequences of an unusually deep and long solar minimum" during the AGU Fall meeting (Dec 2009). (Source: Bad Astronomy and Universe Today Forum)

19 Jan 2010 - M2,3-flare in old region NOAA 1039 - It was the first M-flare since 25 March 2008, that's 665 days ago - an absolute record since measurements began in 1976 (see Archives). Movies at Solarsoft. The S25E88-position seems somewhat off the mark, as the region still has to round the solar limb.

Update: NOAA 1040 produced in a very short timeframe 6 M-flares (source: SEC), after which it remained quiet.

2 November 09 - Timelapse between solar flares - Table underneath depicts for the 3 flare-classes (C, M and X) the longest time (days) that has elapsed between the occurence of 2 such flares. Cut-offs were 60 days for C-flares, 150 days for M-flares, and 240 days for X-flares. As can readily be seen, most of the "records" occured during this solar cycle transit, and really shattered the previous ones in the C- and M-class. Just to be clear: Data do cover the period starting 1976...

1.03 Apr 08C1,2UNK 03 Nov 08C1,6UNK 214
2.11 Dec 08C1,4100905 Jul 09C2,71024206
3.24 Aug 07C2,0096913 Dec 07C4,50978111
4.28 Aug 96C1,3UNK 23 Nov 96C1,0799987
4.07 Jan 08C1,4098003 Apr 08C1,2UNK 87
5.06 Jul 09C1,0102425 Sep 09C2,0102681
6.05 Jan 96C1,3793823 Mar 96C1,5795378
7.19 Feb 07C1,1094324 Apr 07C2,8095364
8.08 Sep 84C2,2UNK 10 Nov 84C1,8459263
9.19 Jan 76C1,0067620 Mar 76C3,0068861
1.25 Mar 08M1,7098931 Oct 09* * 585
2.09 Jun 07M1,0096025 Mar 08M1,70989290
3.20 Oct 95M1,5791222 Apr 96M3,67958185
4.07 Dec 06M2,0093001 Jun 07M1,00960176
5.22 Apr 95M1,2UNK 12 Oct 95M1,57912173
6.04 May 86M1,2472719 Oct 86M4,74750168
6.19 Oct 86M4,7475005 Apr 87M1,14787168
7.06 Jul 06M2,5089805 Dec 06M1,80930152
1.03 Nov 92X9,0732109 Jul 96X2,679781344
2.14 Dec 06X1,5093031 Oct 09* * 1052
3.06 Feb 86X1,7471102 Jan 88X1,48801695
4.30 Apr 76X2,0070007 Sep 77X2,00889495
5.09 Jul 96X2,6797804 Nov 97X2,18100482
6.15 Sep 05X1,1080805 Dec 06X9,00930446
7.24 Apr 85X1,9464704 Feb 86X3,04711286
8.06 Jun 83X1,4420117 Feb 84X2,34421256
9.28 Nov 98X3,3UNK 02 Aug 99X1,48647247
10.21 May 84X2,7449221 Jan 85X4,74617245

22 August 2009 - The solar activity has been very low over the last few weeks and no sunspots have been observed. Interestingly, even if the sunspotnumber would be 0 (zero) for the month of August, then the Meeus smoothed sunspotnumber would still increase (1,78). In fact, 1 group similar to NOAA 1024 in September or 3 such groups in October would be sufficient to keep the smoothed SSN increasing. All this is possible because of the relatively high sunspotnumbers recorded from May till July this year (see SIDC). Obviously, if solar activity continues to be as low as it was during this month, then the smoothed SSN eventually will decrease again and most likely will herald an even deeper minimum than that of December 2008.

Meanwhile, and according to preliminary SIDC-numbers, 30 July 09 marks the last day sunspots have been observed. The longest spotless stretch so far during this solar cycle transit (see my "spotless page") was from 21 July till 20 August last year (31 days). So, if no sunspots appear by the last day of August, a new record for this cycle transit will be set. Nonetheless, regardless of whether this record will be broken or not, it will not change the fact that we are experiencing a deep and very long cycle minimum as shown in figure underneath (SC24-values subject to change: 48 months is a conservative value).

1 August 2009 - Cycle minimum in December 2008? - Based on preliminary sunspotnumbers of the SIDC, the (Meeus) smoothed sunspotnumber seems to have reached a minimum of 1,72 in december 2008. The smoothed values for the months of November 2008 and January 2009 are respectively 1,78 and 1,75. If this minimum is confirmed by a continuing, (slowly) increasing solar activity in the coming months, then SC23 will have last 151 months. This makes it, after SC04 (169 months) and SC06 (153 months), the longest solar cycle since the beginning of the official series in 1749.

5 July 2009 - Biggest sunspotgroup of SC24 so far - NOAA 1024 appeared late last friday and quickly developped into a prominent group on the solar surface. According to NOAA, it has a McIntosh-class Dsi and a sunspot area of 100 MH. However, my own observations tend to confirm earlier conclusions made by Jan Alvestad: type Dai (iregular umbrae that are not symmetric to the penumbra, which itself is also not entirely symmetric).

Since its appearance, this group produced mainly B-flares, a consequence of its mixed magnetic polarities (see figure underneath). Though the latest SOHO-magnetograms show some simplification in the magnetic structure, Dai-groups have 65% chance to produce a C-flare within 24 hours, and there's even a (small) 10% on a M-flare (see tables for flare-predictions). To be watched!

1 July 2009 - The first 20 groups of SC24 - With NOAA 1023, the 20th numbered group of SC24 has appeared. A SOHO image-overview can be found at, lacking only NOAA 1003, 1006, 1020 and 1021. Time for a comparison with SC12 to 14, and with SC21 to 23.

Latitude distribution

SC24-groups show a latitude distribution similar to SC21-23, and appear a little bit farther away from the solar equator than those of SC12-14. However, no groups with high latitude (more than 35°) have been seen so far.

Sunspot Area

Assuming correct area determination by NOAA, it seems about as many groups appeared with areas up to 30 MH than during the two other cycle series. To be clear: These are all very small groups! Not present so far in SC24 are the somewhat bigger groups (100 MH or more), of which 2 to 5 normally should have been seen.


Big groups usually last longer than small ones. In SC24, the lack of big groups is translated into a relatively short lifetime of groups observed so far. There are no groups that have been continuously observed for more than 8 days.


For the last 15 groups of each cycle, the time between the consecutive appearances was determined (months). A group appearing in the same month as its predecessor, was given the value 0. There seems to be not much difference between this cycle and SC12, 13 and 23. In SC22, groups appeared a bit faster, whereas SC14 and SC21 were somewhat slower. No conclusions about the coming SC24-amplitude can be drawn.


As far as records go back (none for SC12 to 14, and only for half of the 20 groups in SC21), it was determined if flares occured in these groups. SC24 ressembles very well SC21 and SC23, whereas SC22 might have been a true outlier (4 flare-producing groups!).


Except for the fact that SC24 produces somewhat smaller and thus short-lived sunspot groups, it looks like the beginning of the new solar cycle is taking off quite normally. Hence, the long inactive period we are experiencing seems to be more a consequence of the very late start of SC24, in combination with a at that time completely finished SC23. To be continued!

14 June 2009 - Guido Gubbels, keen solar observer of the Belgian Solar Section, alerted me on the fact that Catania considered NOAA 1020 on 8 and 9 June as 2 different groups (resp. nr. 109 and 110). What was going on here?

Figure underneath (cut-outs of SOHO-images) surely shows the spots are not the same. Magnetograms clearly show how the white and black spot of the 8-June-group vanish, and how a few degrees higher a new white and black spot develop out of which grows the 9-June-sunspotgroup. However, following the evolution in this area, it becomes also clear that the most eastern spots are located in an area of "white" magnetic polarity, and the western spots in a "black" area. So this concerns indeed different spots (groups), but in the same magnetic area. Moreover, the new spots are located less than 5° of the old ones, and so -at least in theory- they can be considered as being in the same group. NOAA and most other observers were right to consider this one and the same sunspotgroup.

In view of the short lifetime of these very small spots, one can of course ask if these dots are not simply pores in a not so active area. This is -once again- the same question that many observers have been asking themselves quite a lot over the last year...

7 June 2009 - Sunspot Area of NOAA 1019 - Based on drawings by the Kanzelhöhe Observatory from 31 May till 05 June, I calculated the daily sunspot area for NOAA 1019 and compared it with SWPC/NOAA's values. Figure underneath shows the daily results, as well as the best-fitting polynomial (3rd degree). As can be seen, maximum area of the group for both data series occurs in the morning hours of 2 June. However, there is a clear difference in the maximum value of the area, with the calculated value (110 MH) about 40-50% higher than NOAA's (75 MH). This deviation is consistent with Greenwich/MSFC correction-factor. The NOAA-values for 3 and 4 June (end-of-day) seem to be in error.

22 March 2009 - New SC24-group has reversed polarity... - The new sunspotgroup that is visible in today's SOHO-images, has -according to the corresponding magnetogram- a reversed polarity (SC23/25). Though on itself this is not so peculiar (every solar cycle has about hundred such groups, or about 3% of the total), it is already the second SC24-group showing this "aberration": NOAA 1003, visible for just one day (04 October 2008) on the southern hemisphere (-23°), had a polarity equal to that of a unpair solar cycle too (see slide 4 of my presentation). That makes 2 out of 13 (15%), if this group gets a NOAA-number.

14 December 2008 - The polar filament that had announced itself earlier this month with a beautiful prominence at the northeastern solar limb (see e.g. on 5 and 6 December movies and images at Spaceweather and NSO/Sacramento Peak), and that was making a impressive solar transit (see movies of 10 and 11 December at NSO/Sacramento Peak), suddenly disappeared on 12 December (see movie of 12 December at NSO/Sacramento Peak). Apparently, a A3,8-flare at 3:03UT and another flare around 6:00 UT (simultaneously with a flare in NOAA 1009) in a not so nearby and spotless region southeast of the filament initiated a disturbance that would cause the filament to disappear just a few hours later. Movies and images on the websites of LMSAL and SOHO(EIT195). This is called a "Disparition brusque" (sudden disappearance, no flare), it is not a Hyder flare (sudden disappearance with flare at the location of the filament).

3 December 2008 - During the annual gathering of the Belgian Solar Section on November 8th, the SIDC gave a presentation on sunspots and the sunspotindex. With kind permission of Dr. Petra Vanlommel, the pdf-version of the presentation can be found here. Most of the slides are in Dutch, but a few crucial slides are in English. I personally liked very much the slides on the 3-phased calculation of the Definitive International Sunspot Number, as well as the three slides explaining the difference between a sunspot and a pore (slides 32-34).

2 November 2008 - Figure underneath shows some interesting developments in the magnetic region of NOAA 1007. Actually, there is a new group trying to develop just in front (to the west of) the remnants of the original NOAA 1007 group! In the course of 31 October and 1 November, a small negative (black) magnetic area has split off of the leading spot of NOAA 1007. Between these two regions of the same negative polarity, an area of positive polarity has developed last night. So, it now looks on the magnetogram as if there are 2 SC24-areas very close to each other! Visually, it looks as if NOAA 1007 has strengthened again, but actually the leading spot is the newly developped sunspot, while the follower is the old main spot of NOAA 1007. Visually, of the follower of NOAA 1007 there is only a small pore visible (as confirmed during my observation earlier this morning).

In principle, areas with opposite magnetic polarities being so close together, give rise to solar flares. But in this case, the fields seem not strong enough to do so.

4 October 2008 - There is a new sunspotgroup visible on the southern solar hemisphere (as already reported yesterday by Pete Lawrence on the Spaceweather-website). Belgian solar observers saw earlier this morning at least one sunpot clearly in this region.

Interestingly, Locarno (07:15 UT ; Q=2) and SIDC/Ukkel (07:45 UT ; Q=2?) did not report anything just a few hours earlier... Kanzelhöhe (09:03UT) did notice a bipolar group.

My own observations (C8, 68x) do not show "clearly" a B-group: a clear Axx for sure, but if there's still something there, it rather looks like a small photospheric region imbedded in somewhat brighter faculae fields... A greyish pore at most (at least around 8:30UT, with Q=3 and some cirrus). The region is also very nice in H-alpha: 3 closely packed and relatively bright small areas, with some dark fibrils in the neighbourhood.

GONG-images also show the group. NSO-magnetograms clearly reflect an overnight enhancement of the magnetic fields in this region. The polarity is that of a SC23-group... at a latitude of at least -20°... This can possibly still be a high latitude SC23-group. Late June 1997, NOAA 8056 -with SC22-polarity- appeared with a latitude of +17°. See SOHO for magnetogram, and Kanzelhöhe for a drawing. The nearby group is NOAA 8055, a SC23-group (= new cycle) at +15°! And this happened more than a year after cycle minimum and the start of SC23. I have no magnetograms of earlier SC-transits to evaluate how exceptionnal or common all this is. At least this is a new element for discussion!

This group was later labelled NOAA 1003.

10 September 2008 - On Anthony Watts's website, some comments from the SIDC were published today concerning the small sunspotgroup of 21-22 August. It is very likely that SIDC will indeed consider the small specks as a sunspotgroup and that the Wolfnumber will be on full account of the northern solar hemisphere. I fully agree with SIDC that there has been too much discussion on whether or not a sunspotgroup was visible. THE conclusion is that solar activity of the last couple of months has been the lowest of the current solar cycle transition so far.

22 August 2008 - Since yesterday, there is finally a new sunspotgroup visible (Cesar). Based on magnetograms, it is quite simple to determine if a group has SC23 or SC24-polarity. See this excellent link to Spaceweather. Fot those who still have doubts: this new group has indeed SC24-polarity (following/leading sunspot = white/black). See GONG for magnetograms of this area. On the southern hemisphere, the polarity of a SC24-group is of course reversed (follower/leader = black/white).

The group itself has a solar latitude of only +15° (according to Catania). However, examining the latitudes of the first 20 groups during the last three solar cycles, it becomes clear such a low latitude for a new cycle group is certainly possible. Moreover, this group behaves well according to "Joy's law" (the leading main spot is closer to the solar equator than the following sunspot), indicating this is most probably not a "lost" SC23-group from the southern solar hemisphere.

So, it really looks this group can be considered as a SC24-group, but of course it still needs a NOAA-number. Quite a lot of solar observers have not seen this group (not yesterday, not today). It's really a small group, just like the three SC24-groups before it.

6 August 2008 - My presentation (in Dutch) on "Solar Observations in H-alpha" that I gave today at MIRA Public Observatory.

22 July 2008 - Hereby provided is an update (preliminary data) of the graph with the number of spotless days and of the graph showing the evolution of the number of sunspot groups from the old and the new solar cycle. According to these statistical methods, the minimum should take place respectively in July 2009 or November 2008. Both methods have an uncertainty of 6 months (see previous Solaemon's).

Recently, the NOAA/NASA/ISES SC24 panel has confirmed its earlier prediction of a solar cycle minimum in March 2008 (+/- 6 months) on its website. Also, there is still a split on the amplitude of SC24. A very interesting briefing by Mr. D. Biesecker was added to the panel's website.

13 July 2008 - Graph underneath shows the Meeus-smoothed evolution of the monthly sunspot area (1874-present) split up per solar hemisphere. The white area is where both hemispheres are contributing equally. Added to this is the extra activity from the dominating solar hemisphere: blue for the northern, and red for the southern. The last couple of years are especially dominated by the southern hemisphere. Data come from MSFC's Greenwich webpage, and the 1,4 correction-factor was applied on all data after 1976.

24 May 2008 - There has been a lot to do lately on the "Tiny Tims": the smallness of the first sunspotgroups of the new solar cycle 24. These appeared in January (NOAA 0981), April (NOAA 0990) and May (NOAA 0993) of this year, and had respective areas of only 20, 10 and 20 MH (millionths of a solar hemisphere; 1 MH = 3,04 million km2).

So, for the solar cycles used in previous Solaemon reports (see entries for 05 and 19 April), the average maximum corrected area of the first 20 groups of the new cycle were calculated. Also the average for series of 5 groups was calculated, so that this average becomes statistically more comparable to that of the first 3 SC24-groups. These averages and corresponding standard deviations (between brackets) can be found in table underneath. Data used come from MSFC's Greenwich webpage, and the 1,4 correction-factor was applied to all NOAA-groups after 1976.

Cycle    Group 1-5      Group 6-10      Group 11-15     Group 16-20       All groups 1-20
SC 12   68,2 (92,0)    128,8 (101,5)   166,0 (167,7)   116,4 (171,1)       119,9 (135,2)
SC 13  167,6 (208,2)    95,2 (109,5)   119,0 (152,9)    75,6 (137,9)       120,3 (149,4)   
SC 14   48,0 (52,0)    266,6 (476,5)    43,4 (71,0)     12,2 (4,4)          92,6 (245,5)
SC 21    3,0 (1,4)      32,2 (32,5)     44,0 (60,9)     37,2 (49,4)         29,1 (42,1)  
SC 22  268,8 (354,5)    92,4 (66,1)     33,6 (23,4)     36,4 (35,1)        107,8 (193,5)  
SC 23    8,4 (7,7)      14,0 (14,0)     58,8 (108,6)    30,8 (34,9)         28,0 (56,6) 
SC 24   23,4 (8,1)

It may be clear that the first groups of SC24 are not big, but also not particulary small compared to previous cycles. Interesting is that from the very beginning, quite big groups can form. For example, Greenwich group 496800 (+25°) attained a maximum sunspot area of 1113 MH, but appeared only 6 months after solar cycle minimum (September 1901). Because of the occasional appearance of rather big groups, the standard deviation on the averages is very big. It also means most groups of the early cycle are very small. Many groups have an area of only a few MH, and during SC23, 8 of the first 20 new cycle groups got even 0 MH!

10 May 2008 - The SIDC-smoothed Wolfnumbers show that a minimum was reached in September 2007 (5,9 - see graph underneath). The reason this is not frontpage news, is that 5 of the 7 subsequent monthly Wolfnumbers were lower than the smoothed September value. It is thus more likely that the smoothed Wolfnumber will decrease again in the coming months. How long depends on this summer's solar activity and thus the monthly Wolfnumbers. Some simulations for the months from May through August 2008 have shown that if the monthly R-values are between 5 and 10, a minimum around January 2008 will be reached. If the solar activity stays low and the monthly R-values vary between 0 and 5, the smoothed Wolfnumber will continue to decrease. How long will then depend on the further evolution of the solar activity. Last year's prediction by the NOAA/NASA panel of a March 2008 solar cycle minimum (+/- 6 months) seems currently still quite solid.

As solar cycle 23 lasts longer and longer, it is good to compare it with other long lasting cycles (Meeus smoothed values; see table underneath). SC23 started in May 1996 and, including the preliminary smoothed value of October 2007, has already 137 months. That's more than 14 other solar cycles. If the minimum falls in January 2008, it will be the longest cycle in a century. Any minimum in March or later would put it in the top 5 of longest lasting cycles since the official series in 1755 began. SC23 would then be the longest in 150 years. That would be a great experience!

Solar Cycle     Length (months)     Minimum SC23
SC 4                 169            June 2010
SC 6                 153            February 2009
SC 9                 150            November 2008
SC 5                 146            July 2008
SC 14                141            February 2008
SC 11                140            January 2008 
SC 13, 20            139            December 2007
***SC23***           137            October 2007
SC 1, 10             135            August 2007

19 April 2008 - Solar cycle minimum at the earliest in second half of 2008? - Part 2 - Building on the results of Solaemon 05 April 08, for the 6 concerned cycles the difference was calculated between the true cycle minimum and the month for which the number of groups of the new cycle became bigger than that of the old cycle. Smoothed minimum then happens 2 months prior to this break-even-point, with a rather large uncertainty of 4 months.

Then, the standard deviation (sigma) was calculated for the "new" cycle of "Avg SC12-14". 0,5 and 1 sigma were added to the values of "New Avg 12-14". This results in 3 possible curves for SC24, i.e. "New Avg 12-14" with no, 0,5 and 1 sigma added. Also, the values of "New Avg 21-23" were moved 21 months. This means that as from month 21 (smoothed number of groups in October 2007), there are 4 possible evolutions. These increasing curves intersect the decreasing curves of the "old" cycle averages of respectively SC12-14 (blue curve) and SC21-23 (red curve). This results in 8 intersection points as shown in the figure underneath, and thus 8 possible timings for the solar cycle minimum.

If simply the average would be taken of the aforementioned timings, then the minimum would fall in September 2008. However, the uncertainty for this result is 8 months, meaning that the minimum can actually fall between January 2008 and May 2009. That's not vey precise! Finetuning can be done by assuming that it is quite improbable that SC23 will decrease according to the "Old Avg 21-23", in view of recent (March 2008) activity. If then simply the average is taken of the intersection point with "Old Avg 12-14" (the blue curve), minimum could fall in November 2008 +/- 6 months.

05 April 08 - Solar cycle minimum at the earliest in second half of 2008? - Part 1 - In this statistical research, transits to cycles 12, 13 and 14 were considered, as well as transits to cycles 21, 22 and 23. The current transition towards SC24 was compared with foregoing evolutions. As a timereference T0, always that month was taken for which the smoothed Wolfnumber Rs was below 20 for the first time. Raw data from SIDC and MSFC, and without making distinction between NOAA and Greenwich.

Figure 1 represents the smoothed Wolfnumbers of the concerned solar cycles, always with T0 as the timereference. The Wolfnumber of the ongoing solar cycle is already 20 months below 20. All recent cycles had already attained their minimum by then (16 +/- 5 months after T0) and showed a fast increase (see reddish curves). The older cycles clearly were still in their descending branch, and only attained 37 +/- 6 months after T0 their respective minimum. The current solar activity clearly still shows a descending evolution. If the Wolfnumber continues to mimick the evolution of the older cycles, then a minimum can be expected in February 2009, with an uncertainty of 6 months.

Figure 2 provides the smoothed number of sunspotgroups belonging respectively to the ongoing solar cycle and the upcoming one. To avoid too many curves on the same graph, the average of the 3 most recent cycles (red/orange) and of the 3 older cycles (bluish) were used. If groups had a high latitude (over +/-30°), they were considered belonging to the new solar cycle. Obviously, as the new cycle proceeded, lower latitudes were allowed. With the more recent cycles, it can be seen that 19 months after T0, the groups of the new cycle become more numerous than that of the old cycle. This happens only after 38 months with the older cycles. At the moment, the current activity of SC23 (darkgreen) is following very well that of the most recent cycles, but SC24 (lightgreen) parallels much better the evolution of the older generation of solar cycles (new groups). If the number of SC23-groups continues to decrease with the same speed, and SC24 suddenly starts to produce many high latitude groups, the cycle minimum can take place in July 2008 +/- 5 months. However, in view of the March 2008 activity, it seems more probable that the SC23-decrease slows down, and that the number of SC24-groups only increases on a moderate pace. The minimum would then only occur in March 2009 +/- 6 months.

Thus, the start of SC24 is not to be expected prior to July 2008, and in all likelihood might even take place only in the first half of 2009. This conclusion matches perfectly the results one can make from evolution of the number of spotless days. Nonetheless, SC23 would be one of the longest in over 100 years, possibly even in over 160 years.

26 March 2008 - With the apparition of NOAA 0987, 0988 and 0989, there are again 3 sunspotgroups visible at the same time. The last time that happened dates already back to June 2007. With a M1,7 flare, NOAA 0989 also brought us some fireworks. Again, also this dates back to June last year, when NOAA 0960 produced on 9 June the last M-flare. The 290 days in between mark also the longest period without M-flares since satellite measurements began in 1976. The record for the C-flares was broken last year, when between 24 August and 13 December 2007 not a single C-flare was produced (= 111 days!). See Solaemon of 17 March 2006.

It's not that remarkable that there are days with 3 or more sunspotgroups during the period of solar cycle minimum. Table underneath gives per cycle the month of smoothed minimum, the dates before and after the minimum for which there were resp. last and again that kind of days, and finally if the groups appeared at high or low latitude (= whether or not they belonged to the new cycle). The "*" indicates that during the month of the minimum also such days with 3 or more groups were present.

SC23  May 1996*  21 Jun 1996     1-2
                 08 Jan 1996     0-3

SC22  Sep 1986   30 Oct 1986     4-2
                 23 Aug 1986     1-2

SC21  Mar 1976*  21 Apr 1976     0-4
                 11 Nov 1975     0-4

SC20  Aug 1964   29 Dec 1964     2-2
                 20 Jun 1964     2-2

....  ... ....   .. ... ....     ...

SC13  Feb 1890   20 May 1890     2-1
                 10 Aug 1889     1-2
                 08 Sep 1888     0-3

SC12  Dec 1878   07 Nov 1879     4-0
                 11 Jan 1877     0-3

So for SC24, in late March 2008 and early June 2007 we had days with 3 groups or more. It always concerned "old" cycle groups. The table shows that, during the last 4 cycles, this kind of days around cycle minimum was not uncommon. It may be clear however that at that time there was already quite some activity at higher latitudes (SC21 seems to contradict, but there were quite a few groups of the new cycle present, before and after the minimum). In contrast, we have SC12 and 13, where that kind of days was quite unusual. For SC13, there were only 3 such periods in the 21 months around solar cycle minimum, and for SC12 there were only 2... in 33 months!! Thus, the situation for SC24 is not (yet?) as bad as it was for SC12 and SC13, but with only 1 new-cycle-group thus far, SC24 seems really to deviate from its more recent predecessors. To be continued this summer, as the smoothed Wolfnumbers for early this year will be in!

07 March 2008 - Scientists identify the origin of hiss in the upper atmosphere.

02 March 2008 - Last night, some spectacular auroras were visible above Norway. Yet, no solar eruptions were recorded over the last couple of days. Scientists think these "substorms" are caused by magnetic ropes that temporarily connect the earth's upper atmosphere with the sun. The phenomenon is being investigated since 2007 by the Themis-satellite.

05 February 2008 - A few weeks ago, SOHO's quick pick of the week commented on the activity generated by the first SC24-group NOAA 0981. I decided to check on the flare activity one can expect for sunspotgroups with a solar latitude of 25° or more.

Graph underneath shows all such groups since the start of the satellite measurements (GOES). Th black symbols denote groups that have not produced an X-ray flares, the brown have generated at least 1 C-flare, the orange at least 1 M-flare, and the yellow at least 1 X-flare. On the average, 1 out of every 3 groups produces a flare: For SC21, 22, 23 resp. 34%, 39% and 30%. An active group (so one that produces at least one flare) generates on the average about 5 C-flares and 1 M-flare; Above 35°, only about 3 C-flares and almost no M-flares are produced. The northern hemisphere seems to be a bit more active than the southern, but this is probably due to lack of data (only available for 3 solar cycles). Especially during SC22, there were quite a few groups producing high-energetic X-flares (19!), in contrast to the 6 and 3 in resp. SC21 and 23. The most flare-active group since the start of the measurements, NOAA 6659, appeared in June 1991 at a latitude of +31° and produced 27 M-flares and 6 X-flares!

High activity at high solar latitudes may be rare, but is certainly not impossible!

05 January 08 - Now that the first group of the new cycle has finally appeared (NOAA 0981), the graph underneath can give some ideas on how things can evolve. This graph shows for the previous solar cycle transition the smoothed groupnumber g, split up in the part from SC22 and in the part from SC23. In turn, the latter has also been split up per solar hemisphere. It clearly shows that the cycle minimum occured at the same time there was a clear rise in the number of groups of the new cycle (unusual: normally, there is a 10-20 month delay), and that the activity on both hemispheres has been changing significantly. Within a few months, the situation for the current cycle transition will be much clearer.

04 January 08 - First SC24-group has appeared... Finally! - The SIDC Presto announced earlier today: Several observatories have reported the presence of a high latitude sunspot group Catania, Kanzelhöhe. MDI images show a bipolar structure. This bipole is the first of the new solar cycle which actually develops into a visible sunspot group. Solar cycle 24 has arrived!. A nice comparison image can also be found at Spaceweather

The real cycle minimum can happen this month, but it is also possible we could have to wait till mid-2009. This is because there is still (too) much activity of the old cycle on the southern solar hemisphere. See also Solaemon of 12 December 2007 and 03 July 2007.

12 December 2007 - Possibly first SC24-group has appeared - Earlier this morning, Belgian solar observers saw some small spots in a faculae field at latitude +27° on the solar east limb. Also the SIDC and observers on other sites (Cloudy Nights, SolarCycle24) mention possible sunspots in this area. The current SOHO-images do not show any sunspots anymore, but the magnetic polarity of the leading area is "south" (black), as is to be expected from a SC24-group. Even if there are no sunspots in this area and/or the group does not get a NOAA-number, it's certainly rewarding to continue observing this region for the coming days as (small) sunspots may develop at any time.

The appearance of this group does not mean cycle minimum is now behind us. In the past, this minimum usually occured 10 to 20 months after the appearance of the first high latitude group. SC23 was in this respect kind of an exception, because the groups at really high latitude appeared in the same month cycle minimum took place (May 1996). The only groups with SC23-polarity appeared about 10 months prior to that, however on a very moderate latitude (+/-18°). If today's tiny area is/becomes indeed a SC24-sunspotgroup, then cycle minimum can be expected between now and mid-2009. In any case, SC24 really seems to be on our doorstep now!

See also Solaemon of 31 July 2006.

3 November 2007 - According to the SIDC, the provisional Wolfnumber for October 2007 is 0,9. That is as low as in October 1996, but to have an even lower monthly R-value, one has to go back already to 1954. The month with the lowest monthly Wolfnumber occurs often within 5 months of the real (smoothed) minimum. As a consequence, the NOAA-prediction that the cycle minimum will take place in March 2008 (+/- 6 months) is still perfectly possible. There were also 28 spotless days in October. Since 9 October, not a single spot was visible on the solar surface, making the current period already longer than the one from 6 till 27 September. So we are certainly heading for the minimum, but the signal that that minimum is really there, will most likely be given by the appearance of sunspotgroups at high latitudes (>25°). All excitement is in the waiting...

13 October 2007 - Last week, Spaceweather mentioned that the 2 main spots in NOAA 0972 were drifting apart quite fast. However, they did not provide any details. Analysis of SOHO-observations showed that the expansion was due primarily to the fast westward movement of the leading spot. The second graph shows that after one day, the spots drifted much more smowly apart. The maximum expansion speed during the first day was about 1700 km/h (normally 300 to 500 km/h).

6 October 2007 - CME hits Encke: Beautiful images made by STEREO.

19 September 2007 - Hinode is giving us a new view on how sunspots form. No longer are we talking about sunspots as magnetic flux ropes pushing through the solar surface, but as self-assembling magnetic structures. An interesting theory of this complex phenomenon (percolation) was published earlier this year by Kenneth Schatten

2 September 2007 - According to preliminary results from the SIDC, there were 8 spotless days in August 2007 bringing the total amount since January 2004 (month with first spotless day) to 153. This is quite a bit less than during previous solar cycles. As a matter of fact, the last 8 cycles all had already reached their minimum by now. The current evolution of the number of spotless days thus mimics much better that of SC10-15. Also during this cycle transition, there have been only 2 periods with more than 10 consecutive days without sunspots (11 and 13 days). Since SC10, all cycles have had at least 1 period with more than 15 such days. These are all indications that the next minimum is not going to be for tomorrow.

25 August 2007 - The synoptic maps have been updated (2006).

5 August 2007 - Graph underneath shows the 27-day averages (1 solar rotation) of the 10,7 cm Radioflux, the Wolfnumber and the "solar constant" (Total Solar Irradiance, TSI; Watt/m2) during the course of the 23rd solar cycle. Simply said, the Wolfnumber is a measure for the number of sunspots, the Radioflux for the activity they produce in the Corona, and the solar constant for the change in solar radiation (more hot faculae fields means more radiation). In contrast to the Wolfnumber peaking in 2000, the Radioflux and TSI reach their maximum late 2001 with the second sunspotpeak. Noteworthy is also the dip in solar radiation produced by the "Halloween"-groups in October 2003. The active sunspotgroups were so big they more than annulated the extra radiation from the hot faculae fields. Interesting too is that right now, the solar radiation has reached its lowest level since the start of the satellite measurements. As shown in the second graph, TSI already is 0,3 W/m2 under the minimum of the last three cycles. In view of the NOAA predictions (minimum in 2008), it is not excluded that the 27-day TSI-average will fall under 1365 W/m2.

3 July 2007 - For the month of June, the SIDC also mentioned that not a single spot appeared on the northern solar hemisphere. Graph underneath shows the 27-day average Wolfnumber (1 solar rotation) for both hemispheres since 1 January 2005. It is clear that since February 2006, the northern hemisphere has been almost completely inactive, and that the southern hemisphere has determined the overall solar activity during the last few years.

2 July 2007 - According to the SIDC, the preliminary monthly Wolfnumber for June was 12,0. There were also 11 spotless days. The smoothed Wolfnumber for December 2006 is now at 12,8. It is interesting to note that the minimum for SC20-21 and SC21-22 bottomed at respectively 12,4 and 12,8!

Graph underneath shows the evolution of SC23 against the average of the SC9 till 14. Cycles were aligned on their respective minimum, and the month for which the smoothed Wolfnumber decreased under 15, was chosen as the key-month. If SC23-24 shows some similarities with this group, then -in view of the current smoothed Wolfnumber- the minimum can be expected within 18 months (June 2008). However, the uncertainty is rather large: the timing can be 6 months earlier (this is within the NOAA-prediction), but also more than a year later (mid-2009)!

9 June 07 - Tables for the prediction of flares and of the evolution of sunspotgroups were added.

3 June 07 - An overview of the M-flares that NOAA 0960 has produced so far. The logaritmic X-ray plots (GOES 11) always cover the period from 2 hours before till 4 hours after the eruption (10-5 corresponds to the M-level). The sixth eruption actually contains 2 M-flares. Thus, NOAA 0960 has produced in only 60 hours 8 M-flares! A surge occured during the C5-flare earlier this morning. Also a drawing from the 4,5-flare (H-alpha).

2 June 07 - NOAA 0960 is now (08:00 UT) visible as a Ekc-group very near the eastern solar limb. This morning, an eruptive prominence was visible due to a M2,5-flare in this region (close to the following main spot). Compare my H-alpha drawings with those at
This seems to be a nice case of a homologuous flare, this is a flare which repeats itself with similar strength in regular intervals.
NOAA 0960 seems to produce every 8 hours a M2-flare:

01 Jun 07 - 06:51UT - M1,0
01 Jun 07 - 14:59UT - M2,8
01 Jun 07 - 21:52UT - M2,1
02 Jun 07 - 06:11UT - M2,5 
If the most recent flare did not disturb too much the magnetic configuration of NOAA 0960, the next M-flare could be produced around 14:00UT +/-2h. Curious to see what will happen! - Update (02 Jun 07, 20:00UT): Too bad, but no further flares in this series have been produced.

26 May 07 - The prediction of radiation storms (Science at Nasa).

24 April 07 - 3D-images and movies from the sun by Stereo.

4 April 07 - On 29 March, a relatively bright polar facula appeared that was also well visible in H-alpha. Images underneath from Kanzelhöhe and SOHO provide a good comparison. The calculated positions agree to within half a degree: N53E26 (latitude: +53°, longitude: 3°). Technically, it is not a real polar facula (because its latitude < 55°).

28 March 2007 - A study on the differential rotation and inherent motion of NOAA 0918 (0930) and NOAA 0933 was added.

23 March 2007 - Once again, Hinode has made some impressive solar movies. There is one on the X3-flare of 13 December 2006 in NOAA 0930, and a couple of very detailed animations of granules and the reconnection of magnetic fields. See the NASA and NAOJ websites for further explanations.

26 February 2007 - NOAA 0944 is the third appearance of NOAA 0933, and NOAA 0945 is the sixth appearance of NOAA 0918. Table underneath gives for each group the NOAA-number and the evolution in solar latitude and longitude, as derived from NOAA's The Weekly.

	0918 (S04, 359)
	0923 (S05, 004)
	0930 (S06, 009)
	0935 (S07, 008)          0933 (S04, 033)
	0941 (S07, 007)          0940 (S05, 043)
	0945 (S06, 007)          0944 (S07, 044)

NOAA 0918 made its appearance on 23 October 2006, which means this group will exist today for 127 days. However, NOAA 0945 seems to have weakened considerably, and it is doubtful if it can become the third longest living group of SC23 (See Headlines of 16 June 2006 for an overview).

21 February 2007 - A few months ago, Ulysses started its third passage over the solar poles. Surprisingly, at very high southern latitudes, it was bombarded by energetic particles from the NOAA 0930 eruptions in December. Then today, the science team announced that the magnetic solar poles might have a different temperature. See the Ulysses website, as well as their archives for more information about this polar passage.

17 February 2007 - THEMIS, a NASA-project consisting of 5 identical satellites to do research on auroral substorms, is ready to be launched. In particular, THEMIS will investigate what the cause is of this phenomenon: the current disruption model or the magnetic reconnection model. It will be the first time that NASA will launch 5 satellites at the same time. The mission will only last 2 years.

Evolution of NOAA 0918 & 0933

29 January 2007 - NOAA 0940 is the reappearance of NOAA 0933, and NOAA 0941 is the reappearance of NOAA 0935. The respective longitude and latitude of these groups are:

0940: L=040, B=-6                    0941: L=009, B=-10
0933: L=036, B=-5                    0935: L=008, B=-8

The position of NOAA 0941 is my own (rudimentary) calculation; NOAA still has to number this group. This would be the fifth transit over the solar disk of this active region (after NOAA 0918, 0923, 0930 and 0935), giving it a lifetime of already 99 days at this very moment. The group also seems to be slowly moving away from the solar equator.

It certainly is not NOAA 0937, which was 2 weeks ago at position L=349, B=-14°. Moreover, this group rounded the western solar limb without spots.

To get a comparison with how things were one solar rotation ago, one can surf to SWB, Solar Monitor, Spaceweather,... and just go back 27 days (2 January). The view is very comparable to today's, yet one can clearly see how NOAA 0933 has been changed since.

An overview of longliving sunspotgroups during SC23 was given on this site on 16 June 2006 (please scroll down this page).

08 January 2007 - Jan Alvestad announced earlier today that southeast of NOAA 0935, another sunspot group was developing with a reversed magnetic polarity. Thus, this group may belong to the new solar cycle. "May", because just as the small group of July last year, it is at the low latitude of -13°, so still in an area where there is doubt: below 10° it's possibly still a SC23-group, above 20° it is very likely a SC24-group. This group also has not gotten any number by NOAA yet (the small group of July 2006 did not get any at all). Its location is now close to the central meridian. Pictures can be found at NASA's Solar Monitor.

So far, there hasn't been any sunspot group (with or without NOAA-number) with reversed polarity and a latitude of more than 13°.

01 January 2007 - The old sunspot group NOAA 0930 disappeared on 18 December behind the west limb, but is now, a half solar rotation later, rounding the sun's east limb. So, NOAA 0933 is not the reincarnation of NOAA 0930 as claimed a few days ago by for example the Spaceweather-website. Together with NOAA 0934, these are new sunspot groups that were already visible on the farside of the sun from 21 to 23 December (Ref. Spaceweather of 23 December). This explains also some puzzling characteristics of NOAA 0933, like having a different magnetic polarity than NOAA 0930, as well as having a bipolar character and a different longitude (33° in stead of 9°).

8 December 2006 - Magnetic whirlpools feed the earth's magnetosphere. (ESA)

7 December 2006 - NOAA 0930 starts showing some bipolar features, as is apparent from this Catania-drawing. A Dko, with the follower as main spot, seems an acceptable classification.

The X6,5-flare was classified in H-alpha as a 3B-type (large and brilliant). On the website of the National Solar Observatory in Sacramento Peak (OSPAN, USA), some really impressive H-alpha movies of this flare are shown. In the 6-December-clip, one can very clearly see a fast Moretonwave. A few minutes after the explosion, this wave passes over a filament at the southern solar pole. The filament disappears ar first, then reappears after the passage of the wave. A Moretonwave is a kind of solar tsunami propagating through the chromosphere at speeds of about 1000km/s. It has nothing to do with a CME (coronal mass ejection), though the latter was present with this flare. To this testify the type II, III en IV radio-bursts that have been observed by several American stations. Thomas Ashcroft (New Mexico, USA) produced a sound clip of these radio-bursts.

The >=10 MeV protonflux has continued to increase today, probably under the influence of the X6,5-flare. The more energetic protonfluxes have stayed status quo since a couple of hours. Probably, the flux will reach maximum overnight. It is by the way still unclear if the problems with the GOES-13 SXI are due to the 05 december eruption or to some coincident technical problem.

So, NOAA 0930 is still very active and will become even more centrally localized on the solar disk in the days to come. This is bad news for the Discovery-crew that is ready to leave for the ISS tonight (weather permitting). A major flare like the one on 5 or 6 december constitutes a real danger to the astronauts. Groundstations will certainly keep an eye on this early Santa gift!

6 December 2006 - Update X9- en X6,5-flare in NOAA 0930 - At about 16:00 UT, the protonflux reached the proton-event treshold. It is the first such proton-event in 2006. Great pictures of NOAA 0930 and probably H-alpha post-flare loops can be seen at Spaceweather. After yesterday's major eruption, NOAA 0930 has produced also a M1- and a M6-flare. By the way, the X9-flare is "only" ranked number 28 on the list of most powerful eruptions in the last 30 years (source: Spaceweather). The most recent magnetogram clearly shows a mixed polarity, so further moderate to major flares remain possible. A new and powerful eruption occured at 18:47UT: X6,5 in NOAA 0930.

Meanwhile, some major anomalies have occured with GOES-13 SXI, but it is as yet unclear if this is a consequence of the flare or rather because of a coincident technical problem. NOAA and NASA are investigating the problem. For the time being, images from the GOES-12 SXI are used, but this system suffers itself from problems with the light filtering system for many months now, resulting in inferior image quality.

There seems also to be some confusion on the classification of the group. NOAA/SEC classifies it as type Dko, according to Jan Alvestad it's a Dkc, Catania and Kanzelhohe prefer a D-group, while the Royal Observatory Belgium labelled it type H. The classification of sunspotgroups is done always on a visual base, not by using magnetograms. With the white light images I've seen, there seems to be no reason -at this time- to classify this group as D, also because it rounded the western limb two weeks ago as a Hhx-group. Of course, the current activity is quite unusual for what should be a quiet, dying Hkx-sunspotgroup...

05 December 2006 - Powerful X9-flare in NOAA 0930 -Totally unexpected, the Sun has produced a X9,0-flare at 10:35UT today. Images can be found at the SXI-site, a movie is shown at the LMSAL-site. The flare originated from region NOAA 0930 (not the spotless NOAA 0929 to the north) which is rounding the eastern solar limb at this very moment. The group is currently visible as a Hkx-type. As NOAA 0930 will cross the solar surface in the coming days, its complexity will become clearer. Chances on another major eruption are not to be excluded.

In view of the time the flare took place, observers in Europe and Asia were best placed to follow its progress. San Vito (Italy) reported an eruptive H-alpha flare with maximum brightness at 10:38UT (Imp. 2N). On the CloudyNights-website, a H-alpha picture (taken through haze) shows a prominence near NOAA 0930. It is unclear whether this concerns post flare loops, or just a prominence happening to stand in the same direction as the flare. In any case, it is clear that an enormous amount of matter has been ejected, because San Vito observed radio-bursts type II, IV and III. The last type is indicative for highenergetic particles above an active region. Learmonth Observatory in Australia registered the activity in the radio-area. Meanwhile, the protonflux here on earth has started to increase since about noon today. It is however not very likely this flare was powerful enough to reach proton event treshold, in view of its location at the eastern limb. So far, no observers have reported a white light flare or white light prominence.

Today's eruption classifies as number 26 on the list of most powerful flares since satellite measurements began (GOES 1976). It shares this ranking with the 6 November 1980 X9,0-flare in NOAA 2779. The last X-flare already dates back from 15 September 2005 (X1,1; NOAA 0808), and for an even more powerful flare, we only have to go back a few more days: On 7 September 2005, the same group produced an X17. The most powerful flare ever (again, in the last 30 years) reached X28 and took place on 4 November 2003 in NOAA 0486. Powerful eruptions so late in the solar cycle and so close to the solar cycle minimum may seem extraordinary, but perhaps they are less unusual than one might think. For example, there was the big X9,4-flare on 6 November 1997 in NOAA 8100, hardly 18 months after the beginning of SC23. And also in mid-1984, 2 groups produced a X10 and a X13-flare, only 2 years before the beginning of SC22.

2 December 2006 - The SIDC announced that the provisional Wolfnumber for November 2006: 21,5. This is the highest monthly value since May this year. Most of the activity was produced in the southern hemisphere, and there were also only 3 spotless days.

Graph underneath shows the evolution of the daily Wolfnumber per hemisphere. It is clear that the activity on the northern solar hemisphere has been almost non-existent for many months now.

2 December 2006 - Method for determining the location of solar flares - Due to a similar event as described on 28 November, a method is given underneath in order to determine the region in which a solar flare takes place based on SXI-imagery.

  1. Determine the time of the flare through the websites of LMSAL and/or NOAA/SEC. Example: The so-called N45E40 flare started 30 Nov 06 at 00:55 UT and reached its peak at 01:03UT.
  2. Go to the SXI-website.
  3. Click on "Browse".
  4. Leave the "Image width"as is.
  5. The number of images that can be displayed simultaneously is restricted to 36: 6 rows and 6 colums. Because the search is limited to the period around the maximum of the flare, and because there is about 1 image every minute, this is largely sufficient. Example: Choose for this case the value "3" for rows, and the value "4" for columns.
  6. Leave "interval" at "minimum". That way, you get all the images made by the SXI-sensors.
  7. Choose GOES-13 for "Sat". The GOES-12 SXI is not operational at the moment.
  8. Leave "Product" as is.
  9. In "Image Type / All types", choose "Flares".
  10. Undo "Latest". Choose in the boxes "Y", "M", "D", "H", "M", resp. the year, month, day, hour and minute at which the flare peaked. In this example: 2006, 11, 30, 01, 03.
  11. Click on "execute". Occasionally, it happens that the website jumps back to GOES-12. In that case, just repeat steps g. tot k.
  12. There are now 12 images visible in 3 different "soft x-ray" wavelengths (color). One can now, for the same wavelength (color), compare an image around the maximum of the flare with an image prior to the onset of the flare. Example: Comparing the orange-yellow image of 01:02:35 UT (the :35 are the seconds) with that of 00:46:35 UT, a brightening is well visible in NOAA 0927. At N45E40 there is no brightening or change. Hence, the B1,8 flare of 01:03 UT did occur in NOAA 0927.

28 November 2006 - The B1-flare of 27 November (00:37 UT) did occur in NOAA 0926 (SEC), and not in an area at high northern latitude close to the eastern solar limb as mentionned by LMSAL. The difference in location between the two organisations may be due to image processing software used by LMSAL. Visually though, there is no doubt at all.

27 November 2006 - First results of the Hinode. Spectacular images with a resolution of only 0,2"!

26 November 2006 - Graph underneath shows the sunspotarea (NOAA/SEC) per 10° heliographic longitude for Carrington-rotations 2046 to the still ongoing 2050. Almost all activity is produced by the southern hemisphere. It is clear that the past few month's solar activity occured in 2 regions of about 80° that are diametrically opposed. It concerns the regions with longitude 120-190° and 290-010°. Just as coronal holes, this kind of information helps in predicting the spaceweather.

02 November 2006 - NOAA 0921 is a fast growing, but still inactive sunspotgroup on the southern solar hemisphere. However, the group can soon become active, because nearby an unnumbered group has emerged. If the magnetically negative leader of this group and the positive follower of NOAA 0921 move sufficiently close together, then M-flares can not be excluded in the days to come. Nonetheless, a lot will depend on the strength of the local magnetic fields: At the moment they are not big (small spots), which reduces the chance on a big flare.

26 October 2006 - Stereo was successfully launched last night. For videos of the launch: NASA-TV. The scientific mission begins only within a couple of months, after the two spacecraft have arrived at their correct place. If everything goes well, Stereo will make the first 3-dimensional images of CME's (coronal mass ejections).

28 September 2006 - Solar-B (Hinode) was launched on 23 September JT (22 September UT). Videos of the launch cab be found at Jaxa-TV. Websites on Solar-B at MSFC and NAO.

Solar-B is generally considered as the successor of the legendary Yohkoh-satellite (Solar-A; YPOP), that observed the Sun in X-rays throughout almost a complete solar cycle in the nineties. Solar-B does have a resolution three times better though! The satellite will also perform observations in the visual range (especially magnetic fields, with a resolution of 0,2"!!) and in EUV (10 times as sensitive as SOHO!).

"First light" for the telescopes is scheduled for the end of October, and the scientific mission should normally start late November.

22 August 2006 - New group NOAA 0905 has a reversed polarity. To call this immediately a SC24-group is probably a bit premature. Though the group's leading spot is inclined towards the solar equator, it has a very low latitude of only 8 degrees! Without a magnetogram, nobody would call this a new cycle sunspot group. However, in the diagram of 4 August, I did use all reversed polarity groups down to 7 degrees latitude. The biggest "SC23"-group prior to the real start of SC23 was NOAA 7912 (430 MH) at -10° that appeared in October 1995.

Solar Monitor

15 August 2006 - It does not happen very often that SpaceWeather provides incorrect information, but today is the exception. In an attempt to explain the quietness of NOAA 0904, Spaceweather mentions this could be because the considerable distance between the main spots. Flares often occur in areas with sunspots of opposite magnetic polarities. Thus, SpaceWeather ignores here the fact that every bipolar sunspotgroup consists of two main spots with opposite magnetic polarity! If Spaceweather's reasoning would be followed, then even simple B- and C-groups could produce powerful flares! For all clarity: Flares are not produced by the interaction between the two main spots. Flares can be produced when close to one of the main spots, one or more smaller spots develop with a magnetic polarity opposite to that of the main spot. The bigger these spots and the closer they are to the main spot, the higher the chance on a powerful eruption. This certainly is not the case with NOAA 0904

Diagram underneath depicts the birth of a quiet sunspotgroup. A magnetic flux tube breaks through the photosphere and creates the main spots. Where the magnetic field lines come out of the surface, the magnetograms show a white spot; where they return to the solar interior there is a black spot. Often, the leading sunspot is the biggest of the two. Because of the emerging flux, the distance between the two main spots increases! The end of a sunspotgroup is heralded by the weakening and gradual disappearance of the small main spot (mostly the follower).

12 August 2006 - NOAA 0904 seems not to bring all the action that was expected after it rounded the eastern limb a couple of days ago. The number of spots has decreased significantly, and its magnetic field has considerably simplified. See NASA's Solar Monitor. However, the group has the potential to become a naked-eye-object. NOAA 0903 is spotless, at least according to the SOHO-images.

4 August 2006 - Update on the SC24-sunspotgroup - So far, the group in question has been observed only by SOHO, Franky Dubois, and Specola Observatory. It was not seen by other professional observatories as Kanzelhöhe or Catania. Also, preliminary reports by the NOAA and the SIDC do not mention this group. So, whether or not the observed spot was a real (small) sunspot or a pore with a rather long life, remains a topic of discussion.

The graph underneath shows the evolution of the number of groups g during the previous cycle transit from SC22 to SC23. Data were obtained from the magnetograms taken at Mount Wilson, Huairou and by SOHO, and they were applied on NOAA's sunspot data. "g" reaches its minimum in May 1996, just as the Wolfnumber. It was not until 1997 that groups of the new solar cycle became more frequent than those of the old cycle. Groups of SC22 kept on appearing until 1998.

31 July 2006 - SC24-sunspotgroup at low southern latitude - Earlier this morning, observers of the Belgian Solar section saw a small sunspotgroup west of NOAA 0902. It was classified as Axx-2. The position was determined to be longitude 24°, latitude -13°. Specola also observed this group today, but classified it as a pore. SOHO-images showed it already since yesterday evening. Jan Alvestad labelled the group temporarily S669 and classified it Hrx-1. Verification of the magnetograms quickly showed this group having SC24-polarity (see Solaemon of 23 July).

However, the question is of this group really belongs to SC24. The situation is identical to the previous transit from SC22 to SC23. In May 1995, the first potential SC23-group (NOAA 7872) appeared at the same (northern) latitude (13°). The problem was well described at the time by Richard Thompson: This kind of magnetic groups appearing at less than 10° from the solar equator almost certainly still belongs to the old solar cycle ("lost" or "stray" groups from the other solar hemisphere), while at more than 20° from the solar equator, it almost certainly concern groups of the new solar cycle. However, between 10° and 20° from the solar equator, it is a grey zone. Just as for NOAA 7872, the main axis of the sunspotgroup appears to be directed away from the solar equator, hinting this group might be a sunspotgroup from the other solar hemisphere gone astray.

Nonetheless, during the previous solar cycle, NOAA 7872 might have belonged to SC23, because the cycle minimum took place exactly 12 months later in May 1996. This was in line with previous cycles, where the cycle minimum took place 12 to 20 months after the first group of the new cycle had appeared. For this solar cycle transit, this means that the upcoming minimum might take place November 2007 +/- 4 months, pending this group belongs to SC24 or not.

Coming back one more time on SC23: The subsequent new groups of this cycle appeared a few months later in July and August 1995 at slightly higher latitudes (18 to 20 degrees) and with the axis properly directed towards the solar equator. However, it was only at the month of the minimum itself (so May 1996!) before the first group at really high latitude appeared: NOAA 7963 topped +25°, and NOAA 7965 reached -38°. It remains to be seen if the Sun will put up the same show for SC24!

23 July 2006 - SC24-dipole at high southern latitude - Since yesterday, a magnetic dipole with SC24 polarity is visible at -32°. This dipole is well visible on this SOHO-magnetogram: it's located right on the central meridian and has the same magnetic polarity as NOAA 0901 (situated in the northern hemisphere). Just as with the previous SC24-dipoles in August and September last year, no sunspots have been observed (so far) in these magnetic areas.

21 July 2006 - Yesterday afternoon, LASCO (SOHO) detected a large, earth-directed CME. This CME likely originated during the disappearance of a long (+/- 400.000 km!) and fine filament in the southeastern quadrant well visible in the Kanzelhöhe-H-alpha image of 20 July (see Solarmonitor). This filament was not visible anymore during my solar observation earlier this morning.The SOHO EIT195-image of 20 July at 19:13UT shows a very nice arcade in the area. The disapperance of the filament did not cause any flare: the röntgen-flux remained at the A-level all the time (see NOAA GOES). The SIDC expects the particle cloud to reach earth by monday.

15 July 2006 - Any chance NOAA 11000 will appear during SC23? - This question was recently asked on the, with the appearance of NOAA 10900. During the previous 8 cycle transits, the last series of 100 groups started 15 +/-2 months prior to the cycle minimum. Hence, if SC23 wants to produce NOAA 11000, the upcoming minimum should not arrive before October 2007 (+/- 2 months). However, if SC23 mimicks cycle transits 12 to 15, then 29 +/-3 months are needed for the appearance of the last 100 groups. Hence, the upcoming solar minimum should not arrive prior to December 2008 +/- 3 months (to get to NOAA 11000). In view of the low number of spotless days so far (see Solaemon of 7 July), this seems very improbable. Moreover, SC23 would then have lasted 12,5 years, bringing us back a century and a half to find a solar cycle with comparable duration!

13 July 06 - Images of GOES 13 Solar X-Ray Imager (SXI) are now available online. (source: Yahoo-forum)

7 July 2006 - Spotless days - According to the SIDC, the provisional Wolfnumber for June was 13,9. Also, last month only saw 5 spotless days, bringing the total to 52. As already mentionned during previous Solaemons, the number of spotless days is and stays very low. This is reflected in graph underneath, showing the number of spotless days 29 months after the month with the first spotless day (for the transition to upcoming SC24, this was January 2004). We have to go back to SC15 (more than 90 years ago!) to find even less spotless days at this stage of the solar cycle. In fact, in the most recent past 2 solar cycles had already reached their minimum (marked with a green starlet). During the last 8 cycles (Gleissberg??), the period between the month with the first spotless day and the month of cycle minimum was quite stable at 33 +/- 5 months. This stability existed also in the 6 prior cycles, only the period was double as long: 66 +/- 4 months. It is very unlikely we have to wait till 2009 for next solar minimum, but this parameter seems to indicate that the new solar cycle is not near yet. One final remark: There exists no relationship between the number of spotless days and the subsequent cycle maximum (r2=43%)

2 July 2006 - Flares in NOAA 0898 - During my observations this morning (07:00UT till 08:30UT), some solar eruptions were observed in NOAA 0898. It always concerned small eruptions of the SF-type, outside and around the impressive main spot. The B9,3 flare actually consisted of 2 eruptions in 2 locations, as indicated on the accompanying pictures (© Rik Blondeel).

16 June 2006 - Longliving sunspotgroups during solar cycle 23 - The longest living sunspotgroup ever observed firstly appeared on 26 May 1948 and disappeared after 170 days on 11 November 1948. However, according to the IPS, only about 10% of all sunspotgroups have a lifetime of more than 11 days! How does SC23 compare to these statistics?

Based on NOAA-reports for the period January 1996 - April 2006, there appeared 2939 groups, of which 248 reached an area of 400 MH or more. For these last series of groups, it was determined if they were visible during previous or subsequent solar rotations. For 77 groups (31%), this was not the case. This is quite remarkable, because the series contains quite some supergroups, like NOAA 8323 (max. area 1460 MH!) and NOAA 9682 (1210 MH).

The remaining groups were good for 66 double performances, 36 triple appearances, 17 groups held on for 4 solar rotations, 7 groups got 5 and 3 groups got 6 consecutive appearances. This means that 6% of the groups lived at least for a half solar rotation (from the disappearance behind the west limb till the reappearance at the east limb), or at least 14 days. This is perfectly in agreement with the IPS-statistics.

Table underneath gives for the 3 longest living groups of SC23 some additionnal details. It concerns NOAA 8771 (146 days), NOAA 9628 (138 days) and NOAA 0069 (149 days). It is interesting to see that not the biggest groups are living the longest. For example, NOAA 0484 (with an area of 2610 MH the biggest of SC23) "only" achieved 4 solar rotations. Also the number of energetic flares (M/X-flares) per rotation is not really high. As a comparison: In September 2005, NOAA 0808 produced during its rotation alone already 20 M-flares and 10 X-flares! Finally, all 3 groups belong to the southern solar hemisphere. However, this is just a coincidence: 6 of the 7 groups which lived for 5 solar rotations, belonged to the northern hemisphere.

NOAA 8771
NOAABeginEndHel.Lat.Hel.Long.Max.AreaM / X
873920 Oct 991 Nov 99-12°167°8002 / 0
877117 Nov 9928 Nov 99-15°173°82011 / 1
879813 Dec 9925 Dec 99-13°171°5500 / 0
88249 Jan 0020 Jan 00-13°175°4303 / 0
88679 Feb 0018 Feb 00-16°168°1100 / 0
89078 Mar 0013 Mar 00-17°173°400 / 0
NOAA 9628
NOAABeginEndHel.Lat.Hel.Long.Max.AreaM / X
95306 Jul 0110 Jul 01-19°294°400 / 0
955726 Jul 018 Aug 01-20°287°6003 / 0
959121 Aug 014 Sep 01-19°294°7409 / 1
962818 Sep 011 Oct 01-18°291°8806 / 0
967016 Oct 0128 Oct 01-18°289°5300 / 0
971120 Nov 0121 Nov 01-14°284°200 / 0
NOAA 10069
NOAABeginEndHel.Lat.Hel.Long.Max.AreaM / X
1000818 Jun 0230 Jun 02-10°292°5400 / 0
1003615 Jul 0227 Jul 02-7°295°10700 / 0
1006911 Aug 0224 Aug 02-6°299°199017 / 2
101057 Sep 0220 Sep 02-8°300°15205 / 0
101404 Oct 0217 Oct 02-8°303°2300 / 0
101801 Nov 0213 Nov 02-10°306°6305 / 0

9 June 2006 - Quite some sunspot activity, mainly due to NOAA 0892. A nice movie made by Pete Lawrence can be found at Spaceweather. Nonetheless, both NOAA 0892 and 0893 are little magnetically complex, hence the chance for (intensive) eruptions remains very small. The prominence number is at quite elevated levels.

3 June 2006 - According to the preliminary results of the SIDC, last month contained 4 spotless days, bringing the total number on 47. This is not much, considering already 28 months have elapsed since the first spotless day (27 January 2004). As a comparison, table underneath contains the number of spotless periods (consecutive days with R=0) for the previous cycle transit (April 1994 till August 1996) and the current one. The differences are significant. Going to SC23, we already got 4 periods of 11 and 1 of 12 consecutive spotless days, for a total of 171. This time, there has been only 1 period of 7 and 1 of 8, and the total is only 47. Clearly, the Sun is taking her time!


22 May 2006 - The electron diffusion region. See also ESA-portal. The solar wind probably came from a coronal hole, not from NOAA0720 that had fired a couple of solar flares to the Earth just days before.

12 May 2006 - Long range predicition of the solar activity: According to NASA's David Hathaway, SC25 could be the weakest in centuries. See also predictions for solar cycle 24.

05 May 2006 - Beware of the NOAA-classification of sunspot groups! The last couple of weeks, these are often completely off the mark. For example, yesterday there was no C/D/H h x/o/i present on the solar surface! My own classification of the visible groups was Hax, Dro, Hsx, Hsx and Axx. Using Jan Alvestad's website is warmly recommended as a supplementary control on NOAA's Region Summaries!

28 April 2006 - Yesterday, NOAA 0875 produced a highenergetic M-flare (M7,9). The subsequent radiodisturbances were monitored by Thomas Ashcroft (visual and sound).

In April 1995, NOAA 7863 produced the last highenergetic flare prior to the smoothed cycle minimum (M7), which occured 13 months later. In February 1986, NOAA 4713 did the same thing, however this time only 7 months before the onset of solar cycle 23 (M6).

18 April 2006 - Earlier this month, there were a couple of days during which 4 to 5 sunspot groups appeared on the solar surface. Some of these were quite complex, and one was even visible to the naked eye. The (provisional) daily Wolfnumber (SIDC) got well above 60. Gary Palmer even published an overview for the last 6 years how the Sun was looking on the 8th of April (Coronado chat site). Once again, the question was asked how long before next solar minimum.

Table underneath shows the following for all solar cycles since 1850:

  1. Cycle: Number of the upcoming solar cycle.
  2. R>60: Last month prior to the SC-minimum for which the daily Wolfnumber got above 60.
  3. R: Maximum Wolfnumber for that month.
  4. Time Rmin: Time when SC reached its minimum (smoothed).
  5. Delta60: time between b. and d.
  6. #R0: Number of spotless days occured prior to that month (column b.).
  7. R>50: Last month in which the daily Wolfnumber got above 50.
  8. Delta50: time between g. and d.
CycleR>60RTime RminDelta60#R0R>50Delta50
10Nov 185465Jan 185614274May 18558
11Feb 1866118Apr 18671498Mar 186613
12Mar 187674Dec 187833183Jan 187723
13Aug 188669Feb 18904229Aug 188730
14Apr 190068Sep 190117220--
15Oct 191098Jun 19132849--
16Mar 1922127Apr 19231467--
17Feb 193367Sep 19337166--
18Feb 194363Apr 19441433Aug 19438
19Aug 195377Apr 1954891--
20Sep 196385Aug 19641126Feb 19646
21Aug 1975104Mar 19767107--
22Dec 198566Sep 1986989Apr 19865
23Mar 199565May 19961433Okt 19957
24Apr 2006?65?Sep 2007?17?43??

So, on the average 17 months can there be between smoothed SC-minimum and the last month for which the daily Wolfnumber can be above 60. At that time, we already had 105 spotless days. Pointing out again that, except for Rd, there is quite some spread on the averages, even when distinction is being made between SC10-15 and SC16-23. With these averages, upcoming minimum should be in the second half of 2007. A daily Wolfnumber over 50 remains possible.

06 April 2006 - NOAA 0865 produced today the first M-flare on the sun since 02 December 2005, that's 125 days ago (See Solaemon of 17 March). A clip of the eruption can be found on the SXI-website.

31 March 2006 - Oscillations in the Earth's magnetic tail. Clip (ESA Portal)

21 March 2006 - Today, NOAA 862 produced the first C-flares since 24 January, 56 days ago. According to the SIDC, chances on an M-flare are not entirely to be excluded. NOAA/SEC classified the group as Dac, with a beta-gamma configuration. See User's Guide pag. 8 and 9.

17 March 2006 - Since 52 days, the sun has not produced a single C-flare! It was indeed on 24 January that the most recent C-flare erupted in NOAA 0848. In over 30 years of satellite observations, only 5 even longer stretches can be found:

Also M- and X-flares are no longer produced by the sun. In fact, the last M-flare erupted in NOAA 0826 on 02 december 2005 (M2,0 105 days ago). This is still well beneath the 184 days record from the foregoing solar cycle, i.e. from 20 October 1995 (M1,5 NOAA 7912) till 22 April 1996 (M3,6 NOAA 7958).

The most recent X-flare dates already back from 15 September 2005 (X1,1 NOAA 0808), but also this period of 183 days falls far short of the 1314 days established in solar cycle 22 between 02 November 1992 (X9,0 NOAA 7321) and 09 July 1996 (X2,6 NOAA 7978).

17 February 2006 - With the ongoing very low sunspot activity of the last few weeks, one could ask if we are still far from the next cycle minimum, and if there is still any chance we might see a big sunspotgroup.

Table underneath summarizes for the solar cycles 12 to 24:

  1. Cycle: Number of the upcoming solar cycle.
  2. R < 10: First month (after the SC-maximum) for which the monthly Wolfnumber dives under 10.
  3. R: Value of the Wolfnumber for that month.
  4. Time Rmin: Month in which SC reached its minimum (smoothed).
  5. Delta: time between b. and d.
  6. #B: Number of big groups that still appeared. A big group has an area between 1000 and 1500 MH. These are Greenwich-values, the NOAA-values (720-1080 MH) were adapted (factor 1,4*).
  7. #S: Number of supergroups that still appeared. A supergroup has an area between 1500 and 2500 MH (NOAA between 1080 and 1790 MH).
  8. Time: Time between the appearance of the last big/supergroup and the occurence of cycle minimum (column d.).
CycleR < 10RTime RminDelta#B#STime
12Sep 18752,4Dec 18783900-
13Oct 18868,6Feb 1890401026
14Nov 18978,4Sep 1901463235
15Apr 19108,4Jun 1913381033
16May 19228,0Apr 192311104
17Jul 19329,6Sep 193314117
18Jun 19437,6Apr 194410107
19Feb 19533,9Apr 1954141012
20Apr 19648,6Aug 1964400-
21Apr 19755,1Mar 197611107
22Sep 19853,9Sep 19861200-
23Nov 19959,0May 1996600-
24Oct 20058,5--10-

From the data, the significant differences between SC16-23 and the older SC's become clear again. If SC24 is comparable to the most recent solar cycles, then -according to this method- the next solar minimum will likely take place this very year. With NOAA0822 (maximum area 810MH on 15 Nov 2005), we've also (statistically) bagged our big group. Chances for another bog group are very small (+/- 1 out of 10). If the coming solar cycle compares more to the old SC's, then we are at least another 2 years from sunspotminimum. However, chances of seeing one more big group are only slightly higher (+/- 1 out of 6).

4 February 2006 - On the Yahoo-forum (daystarfilters), the following question popped up this week: How long did the last solar minimum last?

As there exist no specific "rules" to define such periods, I took 2 approaches to this problem. On the one hand, the period can be considered for which the smoothed Wolfnumber stays below 20. This value corresponds with a maximum of 1 rather small group of 10 sunspots at most. On the other hand, the period can be considered lasting from the month with the first spotless day till the month with the last spotless day. This period is on the average longer than the one from the first method, and allows an occasional active group to occur.

Table underneath shows all the details for solar cycles 10 to 23. According to the first method, solar minimum lasts 35 months on the average, according to the second method 77 months. One notes immediately there is a big difference between SC 10-15 and 16-23. According to the Wolfmethod, solar minimum lasts resp. 46 and 27 months, according to the "spotless" method resp. 106 and 55 months. This means cycles 10-15 feature relatively low Wolfnumbers with spotless days occuring during almost the entire solar cycle. These are conditions we have not known for at least 80 years!

For the coming cycle minimum, it appears that the minimum period will start in January 2006 (prediction SIDC*). According to the "spotless" method, we have started the solar minimum in January 2004, and we experienced already 25 months and 19 spotless days (including January 2006). Results of Lund indicate the coming solar cycle might be similar to cycles 10-15. Certainly to be continued!

CyclePeriod R<20#MonthsPeriod Rd=0#Months
10Sep 1854 - May 185733Apr 1850 - Apr 185897
11Apr 1866 - Jan 186822Oct 1861 - Jul 186994
12May 1875 - Feb 188058May 1873 - Sep 1883125
13Sep 1886 - Jan 189153Jan 1885 - Dec 189184
14Jan 1899 - May 190353Nov 1895 - Oct 1906132
15Jun 1910 - Nov 191454Mar 1908 - Oct 1916104
16Mar 1922 - Jul 192429Apr 1920 - Jul 192676
17Jul 1931 - Feb 193544Sep 1930 - Jul 193558
18Apr 1943 - Dec 194421Nov 1941 - Sep 194547
19Mar 1953 - Mar 195525Dec 1950 - Oct 195559
20Jan 1964 - Oct 196522Nov 1961 - Aug 196658
21Feb 1975 - Mar 197726Jul 1973 - Jul 197749
22Dec 1984 - Feb 198727Nov 1983 - Jul 198745
23May 1995 - Jun 199726Apr 1994 - Jan 199846
24Jan 2006 (SIDC*)0*Jan 2004 - 25

2 February 2006 - Since 30 January, the sun has been spotless. Table underneath provides an overview on the number of consecutive spotless days and when they occured for the last time. During the last cycle transit, there were no periods of 9, 13, 14 or 15 consecutive days with R=0.

Number of daysBeginEnd
524 Oct 0528 Oct 05
621 Mar 9726 Mar 97
75 Apr 9611 Apr 96
826 Feb 975 Mar 97
91 Feb 879 Feb 87
1025 Dec 963 Jan 97
1121 May 9631 May 96
1228 Oct 968 Nov 96
1331 Jan 7612 Feb 76
1411 Jun 8624 Jun 86
1531 Oct 7614 Nov 76
4213 Sep 9624 Oct 96

22 January 2006 - A spectacular eruptive prominence was photographed on 19 January by German solar observers: Bernd Gährken and Martin Dietzel, including animations!

21 January 2006 - Natural particle accelerator near the Earth (Universe today)

31 December 2005 - Chandra looks at Earth's Aurorae (Source: Universe Today, 29 December)

31 December 2005 - The source of the Killer Electrons. (Source: Universe Today, 22 December)

6 December 2005 - Decease of Marijke van Denneheuvel (79), passionate solar photographer from Castricum, The Netherlands. Some of her pictures were even published on the website of Spaceweather (e.g. 15 June 2003). Her pictures, her endless curiosity and her "Dag allemaal, Bonjour tous,..." will be deeply missed.

5 December 2005 - New views of spaceweather cold fronts (Source: Universe Today)

2 December 2005 - NOAA 0826 is a fastgrowing sunspotgroup that has produced earlier today 2 highenergetic flares. Because this group has a complex magnetic field, more such flares (even X- and protonflares) can be expected. A potential coronal mass-ejection (CME) can be directed towards earth and thus result in severe geomagnetic disturbances.

2 December 2005 - Exactly 10 years ago, the SOHO-satellite was launched from Cape Canaveral. This satellite has become one of the most succesfull solar satellites and its daily images and data can not be missed in the interpretation and prediction of solar activity and spaceweather. Reports on the websites of ESA, SOHO, and PPARC.

12 November 2005 - Earlier this week, the SIDC made mention of the quite constant value of the 10,7 cm solar flux during the past month of October. Preliminary values indicate the solar flux varied between 83 and 72 sfu (solar flux units), that is a variation of 11 sfu or 14% over the average.

This is NOT an unusual situation. For example, the solar flux varied earlier this year for 37 days (20 March till 25 April) between 89,1 and 76,5: a variation of 15%. And from 21 September till 18 October 2004, the flux varied between 95,6 and 86,6 sfu, a variation less than 10%! This kind of variation-poor periods of the solarflux is typical for solarcycle minima, being characterized by even more days with even smaller variations. E.g. the period from 24 January till 12 March 1976 (49 days) during which the solar flux varied between 70,1 and 67,4 sfu: a variation of only 4,3%!

It would be much more interesting if this kind of "stand-stills" occured during a solar maximum. This is much more difficult, because active groups can survive one or more solar rotations, thus forcing the solar flux to vary considerably. A monthly (31-days) variation of 30-50% is quite common, with exceptionnal increases up to 100% (= doubling of the solar flux in less than 2 weeks!), as in July 1982 or in October 2003. Though the solar flux during a cycle maximum continuously rises and falls, table underneath does show that during the last 50 years there were 5 periods with a "stand-still" solar flux lasting at least 1 solar rotation. Weird!

PeriodMaximum FluxMinimum FluxVariation
07 Mar - 05 Apr 1957219,2183,418%
19 Jan - 18 Feb 1969142,2124,613%
04 Mar - 05 Apr 1979203,4177,614%
28 Apr - 26 May 1989212,4180,516%
15 Jan - 11 Feb 2001167,2144,015%

5 November 2005 - Annual meeting of the Belgian Solar Section: Status Solar Cycle 23 - Predictions Solar Cycle 24 (Briefing Solar Section 05 November 2005), as well as a short summary of the meeting (H-alpha program).

1 November 2005 - According to the SIDC, the provisional monthly Wolfnumber for October was only 8,5 (eight and a half), making this the lowest since February 1997 (7,6). This kind of sudden decreases is not abnormal at this stage of the solar cycle: the solar minimum however is still at least 1 to 1,5 years away. The smoothed average remains fluctuating around 31 (April 05: 31,6). October also saw 6 spotless days, with 5 consecutive days showing a virgin solar disc (24 to 28 October). This dates back already from 1997 (6 consecutive days from 21 to 26 March; see Solaemon: "Solar Cycle"). As SC23 continues its descent towards cycle minimum, more such periods can be expected. The 10,7 cm solar flux bottomed on 27 October at 71,6 (provisional value), this is the lowest daily value since July 1997. Fortunately, activity at the solar poles (polar faculae) and in H-alpha keeps solar observing quite entertaining.

13 October 2005 - Who's afraid of a solar flare? (Science&Nasa)

08 October 2005 - Late September, the 76 cm Dunn telescope (New Mexico, USA) made one of the sharpest solar pictures ever: The resolution was only 0,14" or 105 km! The sharpest solar picture ever was made by the Swedish 1m Solar Telescope in 2002, reaching a resolution of only 0,12" or 90 km. Both telescopes used adaptive optics to compensate for the blurring effects of the earth's atmosphere.

26 September 2005 - Comments on the most recent flare-activity in NOAA 10808 and the expectations for the upcoming solar cycle by Dr. D. Hathaway (NASA) at Earthfiles. Also at, which includes an article on NOAA 0720.

23 September 2005 - Quite some prominence activity on the Sun: NASA's Spaceweather, Gema Araujo, Philippe Rousselle, and Marijke van Denneheuvel.

17 September 2005 - Solar minimum explodes! (Science@Nasa).

09 September 2005 - While NOAA 0808 continues to produce highenergetic flares, table underneath shows the strongest flares that have occured since 1976. In view of NOAA 0808's complexity, this may come in handy when ranking flares and other solar and geomagnetic phenomena. 4 of the 5 strongest flares were produced during this solar cycle, with the most recent ranking number 5 (unless NOAA reviews the X-ray peak as was done with the X28-flare).

08 September 2005 - On 07 September, a powerful X17-protonflare took place at the eastern edge of the solar disk. Responsible is NOAA 808, the return of NOAA 798 (prominence at east limb) that produced several energetic events 2 weeks ago. More info at SIDC, Space Weather. Chances on geomagnetic effects are small, but not zero. The chance on similar eruptions in the coming days, with increasing chance on geomagnetic activity, is reasonably high in view of all the CME's produced by NOAA 0808 during its past transit on the backside of the sun.

04 September 2005 - A rather big, but quiescent prominence was visible during this morning's H-alpha session. The faint, complex prominence is at the northeastern edge (+36°) and measures around 130.000 km in height. Great pictures at Gema Araujo.

26 August 2005 - Quite some solar and geomagnetic activity during the last week, especially caused by NOAA 0798, a sunspotgroup with a reversed polarity (but not belonging to SC24 due to its very low latitude!). NOAA 0803 looks promising too, and there are quite a number of filaments and prominences visible, some of which are in the solar polar regions.

10 August 2005 - Interesting evolution of a plasma-cloud.

30 July 2005 - At this very moment (07:55UT), a brilliant X1-flare (optical 3B?) is still in progress in region 0792. It concerns a huge, curved, parallel ribbon flare, and looks like a horseshoe. The bright scar is still easily visible, even when the sun's chromosphere is very obscured by clouds! It's an absolutely incredible sight! My drawings can be found here. Great pictures can be found on the website of Kanzelhöhe.

Last hour (between 06:50UT and 07:50UT) was really amazing with first a M1-flare (2F?) in the same region, an eruptive prominence (out of nowhere) behind the eastern limb, and then around 06:30 the onset of the X1-flare. Over the last 20 minutes or so, the huge prominence at 40° latitude is showing considerable activity too, may become eruptive.

29 July 2005 - NOAA 10792 now seems to have rounded the eastern solar limb completely. I classified this group earlier this morning as Dki (STAR as Dkc, NOAA as Dso (00:00UT)). The group produced also a M4-flare (SXI-clip). Much more important though is that magnetograms seem to indicate that the group is of a reversed polarity (Active Region Monitor, compare with NOAA 0791), which makes it very likely NOAA 0792 will continue to produce energetic flares (possibly even a proton flare). In coming days, the ejected particle clouds of these eruptions will more and more start to influence the geomagnetic field. It will be interesting to see if the program of the Space Shuttle's astronauts (space walks,...) will be adapted if eruptions continue.

28 July 2005 - The sunspotgroup responsible for yesterday's M-flare and eruptive prominence is slowly turning over the eastern limb (Hax; see also Catania, and my drawing (C2-flare)). Since this eruption, this area produced also a M1. The treshold for the proton-event was passed yesterday-evening. According to the SIDC, these protons are probably coming from previous partial halo-CME's produced by this group during the last few days (sun's backside; see SOHO). More energetic eruptions can be expected in the coming days.

27 July 2005 - An unusual chain of events has taken place over the last few hours. Though the solar surface currently shows only 1 small and inactive sunspotgroup (NOAA 10791, Csi), a powerful M3.7-flare has taken place earlier this morning at 05.02UT. This eruption did not originate in NOAA 0791, but in a group that is currently still behind the northeastern solar limb. This group (and probably a southern mate according to SOHO's images of the backside of the sun) is old region NOAA 0786 and has been responsible for quite a few CME's (© Spaceweather/SOHO) that were visible the last few days. These CME's were without any geomagnetic effect, as they were oriented away from earth. The eastern limb now (07.15UT) shows in H-alfa a complex prominence with coronal loops (needleshape with bright tops), and SOHO's coronagraphs (LASCO C2) show a very complex CME. Also this solar eruption is almost certainly directed away from earth and will not have any effect on earth. That's why it is very remarkable that proton-levels are currently increasing. A close analysis reveals however that this increase actually already started yesterday evening, so before the M3,7-flare took place, and that this increase is very gradually. It seems very likely that the arrival of the energetic protons may be connected to the stream of energetic particles from a well-placed coronal hole about 2 days ago (SOHO's archive, 25 July). The geomagnetic field (ACE, NOAA/SEC) is only minorly disturbed at the moment, but if the magnetic orientation of the particle cloud would become southernly, this may quickly become severely disturbed.

Update 15:45UT Drawings at my site and picture at IPS has a nice clip (H-alpha Patrol movies; 03-05UT) of the eruptive prominence. The treshold for proton-event has not been reached yet.

16 July 2005 - Impressive images of loop prominences above NOAA 10786 can be found on NASA's Spaceweather site (15 July 2005). A few days before rounding the western solar limb, thus sunspotgroup became more complex and spawned a few M- and 1 X-flare. These resulted in three proton storms and may cause active geomagnetic conditions over the weekend.

25 June 2005 - The filament visible since a couple of days on the southern solar hemisphere, and earlier this week as an impressive prominence, is no more. It disappeared between 23:19UT yesterday evening (BBSO) and 09:00UT this morning (my observation), and this without an eruption in X-ray. SXI-images (link) show the C1-flare around 03:30UT was associated with spotless NOAA 0780. An image by Meudon Observatory (Paris) at 06:16 UT shows how the filament seems to desintegrate. More images from the global H-alpha network will hopefully provide some clarification. SOHO-images have not shown any CME so far.

Update - SOHO-images show an elliptical halo CME. Geomagnetic activity is possible as from monday noon. First signals of the approaching particle cloud will show up in the ACE-data. From the original filament, only a few leftovers remain.

02 July 2005 - No geomagnetic activity was noted due to the disappearing filament. The halo CME was probably a backside event and so directed away from earth. Some short-lived activity around monday noon was due to a sector boundary crossing.

24 June 2005 - I added my evaluation report on Coronado's Personal Solar Telescope.

11 June 2005 - Some observers have reported this week about the naked eye visibility of both NOAA 0775 & 0776. Equally remarkable were the lightbridges in these sunspotgroups. Some very nice pictures taken by Gema Araujo, with very impressive 09 and 10 June images.

05 June 2005 - Since 27 May, 4 M1-flares were produced by NOAA 0767 (27 May), NOAA 0772 (01 & 03 June) and NOAA 0775 (on 04 June; but behind the eastern solar limb at that time). Clips of these eruptions can be found on the SXI website. None of these flares were responsible for the geomagnetic activity of 29-30 May (Ap = 67) and 04-05 June. These originated from a filament eruption (26 May) and a wellplaced coronal hole.

At this moment, also NOAA 0774 is visible. This group has a SC24-polarity (Active Region Monitor), but because its low latitude (ß = +5°), this is a SC23-sunspotgroup from the southern solar hemisphere. Nonetheless, the first SC24-groups with correct magnetic polarity at high latitude (ß > 20°) remain expected this year.

14 May 2005 - Yesterday around 16:30UT, NOAA 0759 produced a highenergetic M8.0 2B protonflare (see Classification of flares on this website). Images of this eruption can also be found at BBSO. Clearly, a "double ribbon flare" is visible: the anchorpoints are running at both sides of and parallel to the main filament of the group. This filament has apparently not much suffered from the explosion, as can be seen in its evolution. Interesting is that the 14 May H-alpha images show a "bridge" above the NOAA 0759's main umbra, about at the same place where part (the western part) of the flare occured (see TRACE-movie).

The eruption caused a halo-CME. In view of the central location of the flare on the solar surface, and the high speed of the CME, an impact on earth is expected for late this evening or tonight. A magnetic storm and polar light are certainly possible, but as always this assumes a correct magnetic orientation of the particle cloud.

The particle cloud has arrived! In less than 34 hours, it travelled the sun-earth distance. At 05:30UT, its magnetic field has turned strongly southward (negative), thus giving a fair chance aurorae will be visible (especially from the America's). More info on STAR and ACE.

08 May 2005 - NOAA 0756 - Some aspects of the appearance of this big group were examined in more detail. The document has 8 pages (maybe something for a rainy day?...), so here is already a brief summary:

29 April 2005 - With an area of 1030 MH, NOAA 0756 is not only a nice naked-eye object, it is also very near of becoming a supergroup (as from 1080 MH, see Big, Super and Giant sunspotgroups). That would be already the second this year, after NOAA 0720 in January. In my opinion though, the NOAA-classification of Ekc is incorrect. It concerns here a single spot of (only) about 5° in diameter (see this diagram for the McIntosh-classification). Hkx looks much more appropriate to me. Dkc is possible too, as the group "seemed" bipolar during its first apparition on 25 and 26 April (see the archives of SOHO: however, it could also be a lightbridge cutting of part of the penumbra). Moreover, a Dkc is -in principle- much more flare active (CV of 55, while 37 for Hkx), what certainly isn't the case at this moment. In view of the magnetic structure, an M-flare is possible, but still not enough for a mature Dkc-group. Certainly to be continued!

24 April 2005 - The sun today

A spotless sun does not mean there's nothing interesting to observe!

15 April 2005 - The "die-hard" filament, for the first time visible back in January this year, is observable again in H-alpha. This "007" of all filaments simply won't die and has begun its 4th solartransit. On the website of the SIDC, the difference between a "sudden disappearance" and "thermal disappearance" can be found, as well as additional images.
On 18 April, the filament was situated between latitudes -20° and -40°, and it had a total length between 85° and 90°. Hence, the true total length was about 900.000 km, or 70 earth-diameters.

09 April 2005 - It has always been believed that, on Earth, the aurorae (polar lights) from both hemispheres are each other's mirror image. Observations from the NASA-satellites Image and Polar seem to do away with this theory. They found that the polarlightbelts were moving in opposite directions, and the degree of this movement depended on the solar magnetic field (solar wind) and the position of the Earth's magnetic field to the sun. Additional information, animations and links can be found on the website of NASA.

17 March 2005 - The big filament of last month is back, though it is not as impressive, not as long (only 35 earth dimaters or about 450.000 km) and not exactly at the same location (it's actually about 10 degrees closer to NOAA 0735 (currently NOAA 0743). These differences can be easily seen on 2 Kanzelhhe-images. The filament is long enough to become instable and to explode entirely or partially in the days to come.

13 March 2005 - Some observers have reported that NOAA 0742 and 0743 are naked-eye objects. These groups have currently the following features (13 Mar 05 _ 00.00 UT):


According to my naked-eye diagram (2002) both sunspotgroups are located near the blue line. This means the groups could indeed be visible to the naked eye, but it will not be an easy observation. NOAA 0742 is now moving away from the solar center (more difficult visible, unless growth in sunspot area), NOAA 0743 is moving towards the solar center (should become more easily visible).

During my observation of 13 Mar 05 at 09.10 UT, I only saw NOAA 0743 (eagle-eye...).

05 March 2005 - A collage of the transit of the large filament around the western solar limb has been added to the site. Note the disappearance of the eastern part on Feb, 25 and the eruption of the western part on Feb, 27. The prominence gradually moved from equatorial to moderate latitudes.

28 February 2005 - The SIDC announced that the western (leading) part of the long filament has erupted on on 27 January around 10:00UT. In the early morning hours of 25 February, also a part of its eastern zone had erupted. None of these eruptions was accompanied by any flareactivity. Due to its western location, it is not expected the CME will have any influence on earth. A movie of yesterday's explosion can be seen on the website of SOHO (EIT 195).
The solar surface is almost spotless. This very low solaractivity was also expressed by a very low 10,7cm-solarflux (only 75,8). No lower value was observed since August 1997.

It may be very interesting to keep an eye on SOHO's magnetograms. During previous cycles, small sunspotgroups with a reversed magnetic polarity on a relatively high solar latitude (20° or more) appeared some 10 to 18 months prior to the sunspotminimum. Because the coming minimum (and onset of SC24) is expected by the end of 2006, it could very well be 2005 might be the year that groups of the new solar cycle may manifest themselves for the first time. In May 2001, a group with magnetic SC24-polarity appeared at 32° latitude, however, this was fairly typical as the polarity change at the sun's poles was just completed.

25 February 2005 - The over 700.000 km long filament (SIDC) has reached the western solar edge. A very nice prominence is now visible there. Due to its length, it will take the filament several days to disappear behind the solar limb. During this transit, the prominence will gradually move to more southern latitudes (till about -40). It remains interesting to keep an eye on the western limb for the next few days, because IF the filament would become unstable, then a very spectacular eruption could be observed.

19 February 2005 - The M3,5-flare of earlier this morning is NOT originated by one of the currently visible sunspotgroups, but by NOAA 10732 (the not so active successor of NOAA 10720). This group was already spotless for a few days and consisted only of an extensive and bright faculae-field when it rounded the western solar limb the day before yesterday. However, recent SXI images do not leave a doubt: The flare starts at about 10:40UT, and reaches maximum brightness around 11:00UT. Current SOHO (LASCO) images show a CME at the western limb, directed away from Earth (so no geomagnetic disturbance to be expected).
During the next few days, a couple of long filaments deserve attention. If they become instable, they may erupt and fire a CME to Earth.

12 February 2005 - It's raining cats and dogs in Belgium, but that's OK because it is really not interesting to watch the facular leftovers of NOAA 10720. On the southern hemisphere, only a few stable and thus actionless J-groups are visible. The eastern edge has no bright areas that otherwise might indicate for approaching active sunspotgroups. Any geomagnetic activity is to be expected from a favorable positioned coronal hole. There are a few interesting macro-spicules visible on SOHO's EIT 304 images, especially on the sun's northern pole. Interesting date for the upcoming week:

05 February 2005 - Recent satellite-images reveal NOAA 10720 is ready for another solartransit. Helioseismic images made at the end of January reveal some significant spots on the backside of the sun, indicating this group may still contain a large spot area. The last few days, SOHO-images from EIT and GOES/SXI-images in Rntgen clearly show a brightening at the eastern solar edge, indicating the group may still be active. Coronal loops, signs of recent flare-activity, have also been observed. Images of SOHO's coronagraphe (C3) showed some backside CME's probably originating from NOAA 10720. It will be interesting to see if this group will produce the same level of firework as it did during its last solar passage.

23 January 2005 - The geomagnetic storm from the particle cloud, ejected by the X7,1-flare from NOAA 10720, has resulted in aurorae that were even visible in The Netherlands and in Belgium. SOHO- and ACE-data were unavailabe for almost a day, and the Gravity Probe B lost its guidestar for some time. The situation has returned now to normal conditions. Also the Deep Impact probe, on a collision course with the comet Tempel 1, went some time in safe mode till groundcontrol could restart the onboard-electronics.

22 January 2005 - NOAA 10720 has now rounded the western solar edge, but the ejected particle cloud from the X7-flare has severely disturbed the geomagnetic field last night. During its solar passage, the group produced 16 M- and 5 X-flares. Highenergetic flares at this stage (end) of the solar cycle are not unusual. Actually, this kind of powerful eruptions have also occured in March/April 1976, February 1986 and July 1996: all at just a few months from solar cycle minimum. This kind of flares are of course more rare then than during a solar cycle maximum. With a spot area of 1630 MH, NOAA 10720 ranks number 8 of the biggest sunspotgroups of SC23. It was also one of the most flare-active groups. Additional info on the flare-activity in this group can be found at Solar Terrestrial Dispatch. An impressive clip of this eruption, that by the way caused the strongest radiationstorm since October 1989, can be found at the TRACE-website (Movie 100). See also report by the SIDC.

Back to Headlines.

Solar Cycle & Solar Physics

28 October 2009 - Where are the sunspots? is a presentation I gave on 22 October at Public Observatory Urania. A summarized version was also given during the recent "Weekend der Amateurs" of the Belgian Astronomical Association. The current minimum is compared to that of previous solar cycles, and the predictions and underlying theories for the upcoming maximum are discussed.

21 June 2009 - Minimum of other solar parameters - Due to a possible sunspotminimum around the last year's turn, table underneath was put together. It compares the timings of other parameters to the time of sunspotminimum for previous solar cycles. This time difference is expressed in months ("+" is later, "-" is earlier). "RFl" is radioflux, "aa" and "Ap" are geomagnetic indices, "SSC" is Storm Sudden Commencements, "CV" is Classification Value, "Lat" is the latitude of the sunspotgroups, "Area" is the sunspot area of the groups, "g" is the number of groups, "CMX" the number of röntgenflares of the class C, M and X, and "Prom" the number of prominences. For this last parameter, different sources had to be used (references given), and the time difference estimated. The data of the other parameters were Meeus smoothed.

The minimum of these parameters,even of those directly related to the sunspots, clearly do not (always) coincide with that of the sunspotminimum. The differences can even be substantial. Some parameters, like e.g. Ap-index, can not be used as a tool in timing the sunspot cycle minimum, because their minima occur several months later. From the data till April 2009, it can be seen that most parameters have not reached their minimum (though some, like e.g. the Radio-Flux are very near). According to the "Lat"-parameter, minimum can indeed be happening around late 2008-early 2009.

CyclusTime Rmin RFl aa Ap SSC CV Lat Area g CMX Prom
12 Dec 1878 - +5 - - - -6 0 +1 - -
13 Feb 1890 - +3 - - - -21 0 -3 - -
14 Sep 1901 - -1 - - - -9 -9 +1 - -
15 Jun 1913 - +3 - - - -19 0 +1 - -
16 Apr 1923 - +19 - - - -3 +3 +3 - -
17 Sep 1933 - +9 +9 - - -13 0 +1 - -
18 Apr 1944 - +15 +5 - - -13 +1 -2 - -
19 Apr 1954 -1 +4 +4 -/-1 0 -14 +2 0 - -15
20 Aug 1964 -1 +7 +6 -22/-3 0 -15 -1 0 - -12
21 Mar 1976 +2 +7 +8 -27/+7 +4 -10 +11 0 +7 -24
22 Sep 1986 0 +6 +6 -24/+4 +1 -6 0 -5 0 -18
23 May 1996 -1 +15 +15 -24/-1 -1 -6 -1 +3 -4 -4
24 Feb 06/- Aug 07

18 June 2009 - Another explanation for the sluggish start of SC24 is given in this article at Science at NASA. Make sure to read the discussions at Watt's up with that: Frank Hill provides somme additional explanations.

31 May 2009 - After 4 years of work, I finally finished the big CV-project, a research on the solar activity from 1944 till now using the McIntosh-classification and Malde's Classification Value. Yesterday, I gave a lecture on the results of this project during the assembly of the Belgian and Dutch Solar Observers in Asten, NL. Over 6500 observation days and 40000 classifications were combined to show the CV-evolution over the last 60 years, as well as a split up per solar hemisphere, flare-correlations, evolution of the 3 components, and so on.

31 May 2009 - Has the solar minimum taken place? - Some of the charts from my recent update on the evolution of SC23 seem to indicate a cycle minimum late 2008 or early this year. In particular the following methods:

And of course, to that can be added the clear, albeit slow, increase in sunspot activity during the last couple of weeks. Obviously, the upward trend has to be confirmed in the coming months.

08 November 2008 - Presentation on the current solar cycle minimum I gave during the annual gathering of the Belgian Solar Section.

12 October 2008 - Some interesting articles on the Sun and its structure appeared recently.

22 August 2008 - Will the sunspots have disappeared by 2015? The scientific article is by Livingston and Penn, and an extensive discussion on this topic can be found on the website of Anthony Watts. What this can mean for SC24 is depicted in the image below.

15 June 2008 - On July 1st, the Ulysses-mission will be definitively over. See related articles on this very successful project at JPL and ESA, as well as the Universe Today and Wattsupwiththat blogs.

03 April 2008 - Recent results from Hinode and Stereo (RAS meeting):

23 December 2007 - Using detailed images made by Hinode, MSFC-scientists have found many X-ray jets (up to 240/day) that they may be the source of the solar wind. These jets find their origin in magnetic reconnection in the low solar corona. The reconnection, combined with the convective motions at the solar surface, are causing also Alfven waves, which were also observed in very large numbers by LMSAL-scientists. Calculations have shown that these waves are strong enough to power the solar wind.

7 October 2007 - SOHO's pick of the week: The solar corona during cycle minimum. The start of SC24 is not there yet. A similar prediction technique was used earlier this year by the NOAA-panel (Solaemon of 28 April).

25 August 2007 - Detection of a lowenergetic solar neutrino: scientific and popular article.

28 April 2007 - Still no consensus on the amplitude of the next solar cycle. Half of the NOAA-panel expects a high Wolfnumber of 140 +/-20, while the other half forecasts only 90 +/-10. More unanimity exists on the start of SC24: that is expected for March 2008 +/-6 months, which would mean SC23 would last almost twelve years. SIDC-link to the official report of the meeting. See also Predictions for SC24 and the NOAA-overview of prediction methods (source: Spaceweather).

01 January 2007 - My comments on Hathaway & Wilson's preprint were added in the table with SC24-predictions.

23 December 06 - Earlier this week, Science at Nasa published an article about a new prediction for the next solar cycle. According to David Hathaway and Robert Wilson, SC24 would reach a maximum of 160 +/-25. Obviously, some comments can be made about this prediction.

To start, this prediction method is part of geomagnetic precursor-techniques, this is the prediction of the maximum of the next solar cycle based on the geomagnetic activity of the current cycle. Note this is actually a mirror world, as normally the aurorae,... are determined by the solar activity. With their technique, Hathaway et al. determined the maximum of next solar cycle based on the number of aurorae,... in this cycle. In general, most scientists believe coronal holes have something to do with it, but so far nobody exactly knows how things really fit together. I like the idea, but not how it is worked out, because...

The geomagnetic precursor-techniques were very popular for the prediction of SC23. Amongst others, there was Richard Thompson who -using the number of days with Ap >= 25 of SC22- predicted the SC23-maximum to be 165 +/-17 (the 153 +/- 15 which is cited in the article, was done a few years after last solar cycle minimum). These techniques also were of great importance during the research of the NOAA/NASA panel at that time. As has become apparent since then, the solar activity has been about 25% lower than predicted (125; see figure 2 in the article for a comparison between SC22 and SC23!!). So, I'm very, vvveeerrryyy cautious with the precursor results, no matter how beautiful and convincing they might look!

Hathaway uses the aa-index as a geomagnetic index (very similar to the Ap-index, but longer running). One would then expect, because the difference is being made between a aa-r index from the solar activity (Wolfnumber), and a aa-i index from coronal holes,... (interplanetary), he also would distinguish these in the aa-data (aa = aa-i + aa-r). This is by the way very difficult, because both the sunspots (flares!) and the coronal holes influence the aa-index at the same time, and on top of that, there are not enough available (satellite) data to do this. So, Hathaway uses a much different (statistical) approach by comparing the (smoothed!) minimum of the aa-index to that of the Wolfnumber and determine thus aa-r. From there it follows aa-i = aa - aa-r. Hathaway and Wilson then find a very good relationship between the (aa-i)max just before the smoothed sunspotminimum and Rmax of the subsequent SC-maximum.

However, the method used does not make any distinction between months with a low Wolfnumber and a moderate aa-index caused by coronal holes, and months with a low Wolfnumber and a moderate aa-index caused by sunspots. This kind of conditions does exist: At first sight, the solar activity in January 2004 is very similar to that of November 2004 (comparable Wolfnumbers and Ap-index of resp. +/- 40 en 24), but in January there were especially coronal holes at work, whereas in November the very active NOAA 0696 was dominant (see STAR).

So, what's the catch? It appears now that Hathaway's maximum of the aa-i index occurs in October 2003. That is precisely... The month of the Halloween-groups! Hence, because the (aa-i)max is used to predict the upcoming sunspotmaximum, it seems to me that this predicted SC24-maximum is overestimated (due to unsufficiently correcting for the sunspot (flare) activity at that time).

Hathaway's precursor-technique has been integrated in my table with SC24-predictions, but -just as with Ms. Dikpati's- again with very mixed feelings!

17 July 2006 - On 31 May, Raymond Davis Jr. deceased. With his measurements on solar neutrinos, he laid the foundation for the -in the mean time solved- neutrino problem.

10 March 2006 - SOHO now also brings the entire backside of the Sun into view! (Source: Universe Today)

6 March 2006 - Dikpati et al. have concluded from their analysis of plasma movements in the sun that the next solar cycle could be 30-50% stronger than the maximum of SC23. This means a maximum smoothed monthly Wolfnumber between 160 and 190. This is the first method, based on physical parameters, that predicts a strong SC24: Schatten et al., having predicted succesfully the maxima of SC21 and SC22, consider values between 50 and 110 more likely. SC24 would also start only late 2007, and attain its maximum around 2012. See also my presentation for the Belgian Solar Section on 5 November 2005: Status Solar Cycle 23 - Predictions Solar Cycle 24.

19 November 2005 - The most recent activity-prediction by K. Schatten for the upcoming solar cycle indicates a moderate amplitude (Rmax = 80 +/- 30)! See GRL for abstract of Fair space weather for solar cycle 24.

21 August 2005 - Predicting times for clear spaceweather. (Universe Today)

28 July 05 - Astrophysicists have used the Chandra X-ray observatory to show indirectly (via X-ray measurements of 21 sunlike stars) that the sun contains three times more Neon than what can be deduced from its visual spectrum alone. This confirms the location of the tachocline (turbulent transition from the radiation zone to the convection zone) as deduced with helioseismological observations by SOHO and GONG.

09 July 2005 - Some comments on the recent high Wolfnumbers have been added. Together with the low number of spotless days and the low number of polar faculae, this can be considered as an additional argument for a later sunspotminimum (rather in 2007 than late 2006).

28 May 2005 - The Chandra X-ray Observatory has found that Saturn reflects the energetic radiation, liberated during a strong solar flare. Similar to Jupiter, this can be used to monitor powerful eruptions on the backside of the sun.

28 May 2005 - A progress in predicting the occurence of CME's has possibly been made by S. Gibson. Dark areas in the white light corona correspond to low density areas, formed by twisted magnetic ropes. The existence of such cavities in active areas now seems to indicate a CME is on hand.

28 May 2005 - The -so far- most powerful flare in 2005 was produced on 20 January by NOAA 0720. Scientists now report that the protons liberated by this X7,1-flare, already reached earth within 15 minutes. This is not only much faster than usual, it also does not leave enough time to warn astronauts for the incoming radiation. The power of the eruption and the speed of the protons may possibly be caused by the rotation of sunspots around each other. The article and a few nice clips can be found on the website of NASA.

21 May 2005 - This article deals with the prediction of the number of solar flares out of the Wolfnumber, if energetic flares can occur, and what flares there can be expected during the new solar cycle (SC24).

21 May 2005 - Based on structures in the chromosphere, scientists have discovered they can much better predict the speed of the solarwind (from the corona). They found that the chromosphere was much thinner around coronal holes (open magnetic fields), and thicker near active areas (closed magnetic fields). By measuring the time sound waves need to travel a certain height in the chromosphere, they were able to link this to a specific speed of the solar wind. The results were based on observations with the TRACE- and ACE-satellites. See also Solaemon of 30 Apr 05 for other developments in this area.

14 May 2005 - Scientists have discovered the smallest CME so far. The ejected cloud originated from an area on the sun only as big as the earth (normally, these active areas are many times larger than earth), and it managed to reach earth and disturb the geomagnetic field. Observations showed that the magnetic field of the particle cloud was many times more complex than that of its big brothers. The new discoveries are important in the research on CME's.

23 April 2005 - A Chinese-German team of scientists has determined from SOHO-measurements in the UV the origin of the fast solar wind. It was already known for some years that the wind escaped from the magnetic network in the coronal holes, but now it appears this solar wind can not originate from anywhere along these magnetic network lanes. The fast solar wind has its source in magnetic funnels at a height of about 20.000 km, and of which the funnel neck reaches all the way down to the photosphere where magnetic loops from the convection cells supply them with plasma. Further research will be necessary to pinpoint the mechanism responsible for the acceleration (from 10 km/s to 700 km/s) of the plasma.

09 April 2005 - SOHO-images of an energetic X7-flare (15 July 2002) seem to improve our understanding on the theory of how solar flares originate and evolve. Details at Spaceflight Now.

11 March 2005 - A few links to articles that may be of interest:

3 January 2005 - The preliminary Wolfnumber for December 2004 is only 17,9. This is the lowest since July 1997 (R = 10,4). The next solar minimum is still expected to occur in October 2006, with an uncertainty of 4 months.

Back to Headlines.

Climate topics

13 January 2011 - Today, the VRT reported on the flooding that is taking place over various areas in the world (Philippines, Brazil, Sri Lanka, Australia, and the heavy December snowfall in USA and Europe). Amazingly, they did not blame this on CO2 or global warming, but on a natural phenomenon called... La Niña. The movies are very instructive. Just a reminder: El Niño en La Niña exist already for hundreds of years and longer, so well before IPCC summoned CO2 to explain 20th century global warming. Personally, I'm very pleased with our national broadcast corporation starting to differentiate between the causes that affect (extreme) weather. Underneath the most recent Jason-image of the Pacific-region showing the still obvious La Niña.

10 January 2011 - Can most of the rise in the satellite-era surface temperatures be explained without anthropogenic greenhouse gases? - Interesting study by Bob Tisdale on the WUWT-website indicates that natural variables could be responsible for approximately 85% of the rise in global surface temperature since 1982. This basic evaluation indicates the secondary effects of ENSO require further research. See also my own rudimentary research on this matter at Reconstructing the Climate Change (February 2007).

19 December 2010 - Another one for VRT's blunder book. Today's political program "The Seventh Day" took 2010 in review. At one point, a clip was being shown with the worst catastophes the world had experienced this year (based on AP's article?). It boiled down to only 4 (!): Floods in Pakistan, floods in Europe (and Belgium), the Haïti earthquake and the oil disaster in the Gulf of Mexico. Not such a bad choice, but they were intermixed with UN secretary-general Ban Ki-moon's speech at the Cancun climate conference. This implies that climate change causes earthquakes and blows up oil platforms. Yikes!... It also shows there were very little catastrophes in 2010: Otherwise they would surely have been shown in the clip.

In the discussion afterwards, that bald guy (no idea who that is) adds the forest fires as a 2010 catastrophe and starts explaining how this creates a positive feedback (CO2 causes drought => drought causes forest fires => forest fires creates more CO2). He should better have read NOAA's analysis on this. Oneliners such as "you do not negotiate with nature" were properly abused to suit his own benefit. Actually, in those 7:37 he uttered more rubbish than I care to comment about. It all boils down to CO2 as being the main climate change driver, and that it is a settled fact.

I, and many, many others do not agree with these two statements. Watts up with that or CO2-Science are just a few of excellent websites to find out how things really work. Watching the nonsense of today's discussion, it's really no wonder people's support for man-caused global warming is declining!

17 August 2010 - Why rare events are a certainty - This post by Roger Pielke Jr. makes some relevant reflections in view of all the extreme weather that is experienced by Russia (notice the cold patches...), China and Pakistan/India (monsoon has perfectly natural causes like El Niño or PDO), Central Europe (some very thoughtful comments by President Havel on the Czech floodings in 1997 and 2002), and South-America (it's winter there!...). These are extensively covered by -at least- the Belgian media, probably because of the lack on hurricanes (globally) so far...

Weather is not climate!

12 December 2009 - The Ten Commandments of an IPCC-scientist

Above all there is only the IPCC
Just its doctrine thou wilt see
Attend all climate conferences with ten thousands or more
Worship Jim Hansen and Al Gore
Mute all those anthropogenic warming sceptics
By using plenty of spaghetti hockey-sticks
Ignore satellite measurements and natural factors
Dramatize all available catastrophes and heat records
Tinker with temperature data at your convenience
And never, ever, change your allegiance

10 December 2009 - Before this gets completely out of hand: The B17B iceberg (140 km2) upon which the media (VRT...) are so extensively reporting, is just a small piece from the giant iceberg that broke off from the Ross Ice Shelf (Antarctica) in 2000. The biggest iceberg of that break-up, the B15, had the fantastic area of 11000 km2. But even that one was dwarfed by the iceberg seen in 1955, having an area of 31000 km2 (Solaemon of 27 March 2008 for references), just to put things in perspective. B17B is the remaining piece of B17 (see picture underneath) and was tracked from its very beginning. This movie from ABC-news shows the distance B17B has already travelled. So, it was not "discovered" yesterday, and it's also not on a Titanic-course with Australia, simply because by then it will have broken down in numerous and much smaller icebergs. If it wasn't for COP15, not a word would have been mentionned about B17B. And by the way: The breaking off of icebergs in 2000-2001 was not so much related to warming temperatures, but much more to the influence of the sea currents on already very big ice shelves (see for a movie of this effect in the Arctic). More info on and images of icebergs at AWS/AMRC.

05 December 2009 - Because of the upcoming climate conference (COP15), another page was written based on the book "Onze planeet wordt heet! Global Warming bij ons" by Jill Peeters. This article deals again with everything going wrong in the current climate research. I hope to have a translation into English soon, but the images are self-explanatory and most of the links are to English sites.

The CO2-Science-site has also a special (with videos!) on COP15.

12 November 2009 - Some interesting gatherings are on the agenda next week.

17 October 2009 - The VRT, as most other international media, commented the last few days on the Catlin-expedition and the thinning north polar ice. Reactions on the WUWT-website. Again: There is more going on at the poles than just some warming of temperature or seawater. The natural variations in sea- and aircurrents play -as far as I am concerned- a much more important role.

8 October 2009 - Today, the VRT talked about a crystal-ball-research by the KUL. Because of the increasing global warming, there would be more severe rain showers like the one of last night resulting in more regulary overflowing sewers. Of course, no global warming is needed for that: just continue to asphalt the remaining green areas, keep allowing to build near rivers or in depressions, fill upo those ditches, and -certainly in this season- do not clean up those tree leaves. Success guatanteed! Just a reminder that Mr. Van Ypersele, professor at the ULC (French-speaking KUL), is the vice-chair of the IPCC, which certainly wants to put its stamp on the upcoming Kopenhagen-summit.

1 October 2009 - Last week, our national broadcasting pride reported a thickening ozon layer. The Antarctic reality is quite different: the 2009 ozon hole was relatively very large and -especially- one of the thinnest since the start of the measurements. The ill-suggesting text is obviously great publicity for the Kopenhagen-summit and Kyoto-II: "Look what we can do if we do the effort together." But again, the reality tells a different story.

30 September 2009 - Based on GISS-data from January till August 2009, it looks like this year is going to be warmer than 2008, but certainly not a record-setter. The prediction is 0,66 +/- 0,04 °C babove the 1951-1980-average based on temperature data from 1985 till 2004. If one uses temperature data from 1880 till 2004, then global temperature can be 0,63 +/- 0,04 °C.

1 June 2009 - Based on GISS-data for the first 4 months of 2009, it seems this year might be a bit warmer than 2008. The prediction is 0,55 +/- 0,06 °C above the 1951-1980-average based on temperature data from 1985 till 2004. If one uses temperature data from 1880 till 2004, then global temperature can be 0,49 +/- 0,08 °C. 2009 is certainly not going to be a record year.

02 May 2009 - The Nenana Ice Classic 2009: The ice of the Tanana-rivier went out May 1st, that is 3 days earlier than the longterm average.

19 January 2009 - A few weeks ago, the Royal Meteorological Institute of Belgium (RMI) published the results of its study on the climate evolution in Belgium. "Eye on the Climate" covers the period 1833-2007 and is a well-balanced and thorough report on the various climate parameters and the possible factors that can influence the climate in Belgium. There does not seem to be an English version of this report, but it is highly recommended to take that French dictionary and read the entire text!

Probably the most important conclusions concerning the weather parameters are:

Most important remarks concerning the climate factors are:

On climate models:

New topics (at least to me):

Terug naar Headlines.

30 December 2008 - Because of a press release by the German Insurance group verzekeringsgroep Munich Re (see also the website of VRT) on the catastrophical year 2008, hereby again an overview on the number of hurricanes in the Atlantic Ocean (because it is the longest running data series...). The images show, since 1851, the number of hurricanes per category (Saffir-Simpson scale), the five-yearly average number of hurricanes, number of hurricanes versus intensity, and intensity versus the number of heavy hurricanes (categories 4 and 5). Though there were 3 hurricanes in the Atlantic Ocean above the longterm average (8 versus 5,3), 2008 certainly does not belong in the group of exceptionnal hurricane years (like e.g. 2005). Both in intensity as in number, one can easily find a dozen of years for which the situation was much worse. Since the beginning of the observations, there do occur a few hurricanes more (comparable to the periods 1948-1954 and 1884-1889), but the intensity clearly is less (like e.g. in 1948-1954 and especially in 1955-1964). Just the fact that there have existed similar periods during which number and intensity are comparable to nowadays, while at the same time the CO2-concentration was about 20% lower than it is today (+/- 310 ppm around 1950 versus +/- 380 ppm now), clearly show there is no link between the global temperature increase and the evolution in number and intensity of the hurricanes. The reasons cyclone Nargis (category 4) could make such a mess in Myanmar are not climate related: a large part of the country is beneath sealevel, there is a large-scale deforestation of the mangrove giving the water a free passage, and finally the military regime in Myanmar did not intervene timely resulting in a (too) late evacuation and -after the passage of the hurricane- and significantly delaying the aid effort.

29 October 2008 - According to the WWF, CO2 now also is a pollutant! Apparently, the "greens" forget that plants need CO2 for their photosynthesis, a process that's the base of the world's food chain. But just like a week ago when the WWF, "coincidentally" with the EU-summit, totally unnecessary send out another doom story, it's also this time completely wrong.

By the way, I've always wondered why the University of Leuven was so anxious to promote anthropogenic global warming. Now we know: Professor van Ypersele has all of a sudden become the vice-president of the IPCC.

Meanwhile, the Belgians were scraping the first ice of their car's windows this morning...

20 September 2008 - Remaining Arctic sea ice one of the smallest and the Antarctic Ozonhole one of the biggest... since official measurements began about 30 years ago...

14 September 2008 - During the last few days, colorful sunset and -rises were seen in Europe and northern America. They are caused by the distribution of dust and SO2-clouds released by the Kasatochi volcano in Alaska (7-8 August). A beautiful movie can be watched on the websites of Spaceweather and Anthony Watts. Of course, there is some speculation on whether this might cause some global cooling! Kasatochi will probably contribute to a already cooler 2008. Earlier this year (mid-February), even more impressive sunsets could be seen (especially in Europe). These were not caused by volcanoes (e.g. Chaiten), desert dust or smog, but probably by polar stratospheric clouds.

10 September 2008 - Based on GISS-data of the first 8 months in 2008, it looks like this year may be significantly cooler than its recent predecessors. The prediction gives only 0,44 +/- 0,04 °C above the 1951-1980-average based on temperature data from 1985 till 2004. If temperature data from 1880 till 2004 are used, then global temperature can be 0,43 +/- 0,04 °C. It's becoming more and more likely that this year is going to be 0,2 to possibly 0,3 ° cooler than the last couple of years.

24 May 2008 - Based on GISS-data of the first 4 months in 2008, it looks like this year may be significantly cooler than its recent predecessors. The prediction gives only 0,40 +/- 0,07 °C above the 1951-1980-average based on temperature data from 1985 till 2004. If temperature data from 1880 till 2004 are used, then global temperature can be 0,36 +/- 0,08 °C. Some caution though. In 2006, a cool spring was more than compensated by a very warm last quarter. It can not be excluded that something similar occurs in 2008. After this summer, it will be clear if global temperature really has taken a dive.

19 May 2008 - Quietly, that's how the Nenana Ice Classic has been this year. The ice of the Tanana-rivier only went out May 6th, that is 2 days later than the longterm average.

03 May 2008 - According to some German scientists, the global temperature will hardly increase during the coming decade. This is because of a natural cycle of the oceans that would make them cooler and thus the oceans would camouflage the global warming (VRT-article, Universe Today-article,, Junkscience_01 May 08). As far as I and many others are concerned, this is nothing new (AMO, El Niño,...: see my study), for the IPCC obviously not. If 1 natural factor can have such an effect, couldn't it be that this and other natural factors can explain the observed evolution in global temperature during the past century? But this would mean anthropogenic greenhousgases would not play any role of significance... (uh oh!) Anyway, it is big time the IPCC expands the number of natural factors in its long term climate models and actualizes them (PDO 1, PDO 2). Tactically, this is of course a smart move: whatever the temperature evolution in the coming decade, the IPCC-boys (and -girls) will always be right. Interesting evolution!

02 May 2008 - Last week, the WWF found it necessary to toll once again the alarm bells on the melting of the arctic ice and all doom related to it (see the VRT-article). It always amazes me that organizations as the WWF forget to mention that last month, the northpole sea ice had a larger surface area than during the past 4 April months, and even bigger than for example in April 1996 or April 1989. Of course, after the record ice loss during the summer of 2007, the ice conditions surely have changed. However, the question is how exceptionnal this all is. WWF and co. seem to suffer from a permanent memory loss when it comes to the 30's and 40's of last century. At that time, there was also significantly less polar ice than the 1979-2000-"average", and the North West passage repeatedly stayed sufficiently clear of ice to allow for navigation. What's really amazing is that the condition of the polar ice can change so significantly in so little time. Yet, the Southpole clearly shows this is possible. And we do not need to worry about the polar bears. They have already survived the waxing and waning of the polar ice for millennia and thus will continue to do so. By the way, the polar bear evolved from the brown bear, possibly as recent as during the last glaciation hardly 12000 years ago. Talk about adaptation! Perhaps the WWF should better do something about the yearly "harvesting" of the more than 500 polar bears in the arctic region. With such a rate, there will indeed be not a single polar bear by 2050, but it will not be caused by "global warming"!

27 March 2008 - Our national broadcast center VRT once again used the panic switch yesterday. However, some crucial aspects are missing in the story.

It may be clear that there is a significant amount of variability in the evolution of the south pole ice, and that there is no reason to assume human emission of CO2 got anything to do with it.

1 december 2007 - A word on the rubbish that Oxfam has send into the world last week. 500 natural disasters per year equates at least one new disaster every day. Nowhere it is written what Oxfam considers as a "disaster". Moreover, according to Oxfam, it's only about weather disasters, so earthquakes, volcanic eruptions,... are not even been taken into account. There is also no reference to an article or organization on which they based their data. But the 4-fold increase over the last 3 decades is certainly not due to the number of hurricanes. That number is, with an average of 88/year, still as high as in the 80s, and even lower than in the 90s (97/year) (Unisys).
By the way, has it already been on the radio or TV that this year was really hurricane-poor for the Atlantic (5), and that the professional predictions were way off the mark? 2006 was also hurricane-poor (4) and badly forecast.
It's simply wrong when organizations try to press through their agenda by abusing the climate problems. The favorite method seems to be to present half-truths ("1 side of the medal"). Unfortunately, it has become the fashion, as was also shown just a week ago when our national weatherwoman promoted our national ecological footprint. Belgians were painted as big consumers. That we use lots of this energy to produce things was not even mentioned. Is it that hard to compare the average consumption -energy and personal consommation- of a person (the famous ecoprint) with what a person produces as a yearly average (e.g. via the GDP)? That chart, as represented underneath, puts the situation in their proper perspective! It is immediately clear that despite the restrictions of the used parameters (GDP says nothing on the main economical activities like tourism, bancs,...; and the ecoprint does not make a distinction yet on the type of the used energy sources like nuclear power, fossil fuels,...), halving the ecoprint of an industriliazed country means a diminution of the production for most of them. Thus, the question is how such a country can reduce its ecoprint without too much harming its production, whereas for a third world country it is how it can increase its production without leaving too much of an ecoprint. These are the interesting questions!

13 October 2007 - Al Gore and the IPCC have won the Nobel Prize... for Peace. Is that because of the "consensus" claimed by the IPCC? Or because of Al Gore's unsuccessful Live Earth concerts? Thank goodness they did not get the Nobel Prize for Physics or Chemistry! The Oscars for "An Inconvenient Truth" were well deserved though. Regardless the point of view being advocated, you can't make documentaries much better than that. Well, except for Michael Moore perhaps...

7 October 2007 - Readingstuff: On the Thermohaline Circulation" and Unusual Windpatterns as possible explanations for the evolution of temperature and ice area in the Arctic. And there is also a reply on the article of Lockwood and Frohlich (Solaemon of 15 July 2007).

19 September 2007 - Based on GISS-data for the first 8 months of this year, it remains possible that 2007 becomes one of the warmest years since measurements started in 1880, but no record breaker. The prediction is 0,73 +/- 0,04 °C above the 1951-1980-average based on temperature-data from 1985 till 2004. If temperature-data from 1880 till 2004 are considered, then global temperature can still attain 0,69 +/- 0,04 °C. Last year, the average temperature deviation was +0,65°C. The record is for 2005 with +0,76°C, with 1998 a distant second (+0,71°).

15 August 2007 - More rubbish on arctic polar ice - VRT (the Belgian/Flemish broadcasting corperation) announced today on the rapid melting of the arctic polar ice. The daily evolution can be well followed on websites like for example Alistair McDonald. Clearly, the ice concentration has strongly diminished during the last decade. This should all be a consequence of the global warming which in turn is caused by manmade greenhouse effect. The latter is of course complete nonsense. As this graphic shows, current temperatures in the arctic territory are comparable to those from the period 1930-1940. Moreover, the rate at which the temperature increased in the period 1890-1940 is identical to that of the last 30 years. At the time, there existed apparently as "dramatic" news articles on the disappearance of the polar cap as there do now. If the actual melting is caused by anthropogenic CO2-emission, then what was the cause 70 years ago? Worse, if CO2 is really the cause of all the melting, how then to explain the temperature decrease between 1940 and 1965, in view of the permanently increasing CO2-concentrations during the twentieth century? Again, a number of perfectly natural causes are available, like for example North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. That once the ice is gone, it would never return, is just a fairy tale. And it certainly is of no concern to the polar bears: they have never been so numerous as during the last couple of years.

30 July 2007 - More rubbish on hurricanes - VRT (the Belgian/Flemish broadcasting corperation) and the press agency Reuters announced today that the number of hurricanes has doubled over the last 100 of years, and that this is due to -manmade- global warming. As shown by figure underneath, this is absolute nonsense. Both around 1885 and 1950, the 5-year average number of hurricanes was comparable to nowadays. This can not be explained by the CO2-evolution. A much better relationship exists with the AMO (Atlantic Multidecadal Oscillation), a perfectly natural variation in surface temperature of the Atlantic Ocean. There is also a consensus that a strong (positive) AMO produces more powerful (category 4 and 5) hurricanes. Of course, other factors (El Niño,...) contribute to the yearly variation in the number of hurricanes.

15 July 2007 - An interesting scientific article from the hands of Lockwood and Frohlich" that should prove once again that the sun is not responsible for the climate change in the last half century. Of course there are the confirming comments by the always so certain RealClimate-boys, and the denial by the always so sceptical Junkscience (12 July 07).

28 May 2007 - How not to measure temperature!" These data are being used by GISS. Simply incredible! (sources: Anthony Watts; Climate Audit)

26 May 2007 - Based on GISS-data of the first 4 months in 2007, this year seems to become again one of the warmest since 1880 (start of worldwide temperature measurements). It is predicted that temperatures may rise 0,75 +/- 0,06 °C above the 1951-1980-average based on data from 1985 to 2004. Using data from 1880 to 2004, the global temperature can still attain 0,66 +/- 0,08 °C above average. Yet a word of caution: In 2006, a cool first quarter was overcompensated by a very warm second half. It can not be excluded that the reverse will occur in 2007. After summer, it will be clear if global temperatures have really started to decrease.

24 April 2007 - Video The Greenhouse Conspiracy", an Australian documentary (1990) on climate change which goes very well together with The Great Global Warming Swindle" (Google Video, Junkscience).
Meanwhile, Lyman et al. have issued a correction to their data on oceantemperatures. For the years 2003-2005, there is no clear cooling trend anymore, but rather a stagnation. After 10 years of continuous increase, this change in trend remains surprizing and interesting. To be continued.

14 April 2007 - Today, it was about 25°C in Belgium. According to statistics on the KMI-website (climatological) and their book "Climate averages and weather extremes in Belgium" (1833-1990), that's not so unusual. At least once every 10 years, Uccle gets a day with temperatures over 25°C, and 7 out of 10 even over 20°C. From 16 till 18 April 1949, three consecutive days got more than 28°, and from 1 till 4 April 1946 it was between 20 and 26°. In 1952, there were 11 April days with more than 22°. Other years with warm April days (+/- 25°) were 1841, 1865, 1888, 1893, 1894, 1939, 1968, 1969 and 1993. However, it is so that in Belgium, no other period (since 1833) than the current has been with monthly averages continuously more than 1 standard deviation above the 1833-2006 average. For Uccle, this period is now lasting already for over 7 months (since September 2006). Previous long periods were in 1945 and 1947 with 6 months.

23 March 2007 - The Great Global Warming Swindle": an excellent counterweight to Al Gore's Oscar-winning An Inconvenient Truth. (Google Video, Junkscience)

23 March 2007 - The Sun is possibly influencing climate and the ozon layer. Also the urban heat effect stays a very good alternative to explain at least a big part of the global warming. (Source: Junkscience)

10 March 2007 - Is the solar system warming? Though it may be just a coincidence, clear signs of warming have been found on Pluto (2002), Triton (1998), Jupiter (2006) and Mars (2007).

27 February 07 - Some results of my research on the causes of climate change were added. See Reconstructing the Climate Change.

12 February 07 - My comments concerning IPCC's SPM4 which was published early February were added to the document.

21 December 06 - GISS-temperature data including November 2006 confirm this year will be about 0,15°C cooler than 2005. That is especially because of the warm post-summer which compensated the rather cold 2006 onset. 2006 will probably become the 5th warmest year since 1880. See also Solaemon of 24 September and 11 April 2006.

14 October 06 - An Inconvenient Truth is a fine documentary dealing with most topics used by the proponents of anthropogenic global warming. Al Gore is outstanding as an orator in this pedagogic masterpiece. The applause of the audience was well deserved.

Eventually, the movie will only be surpassed by the truth itself.

It may be clear that this documentary provides only a onesided point of view. The climate sceptics are mentioned occasionally, either directly by being ridiculed (e.g. gaz- and oil-lobby,...), either indirectly by being minimized (e.g. "...greenhouse gases and other parameters...").

The strongholders of anthropogenic warming have been refuted or questioned by websites like CO2Science or Junkscience. It concerns, amongst many other, the retreat of the Kilimanjaro glaciers, the sea level fluctuations, the comparison of CO2-measurements, the number of hurricanes, the temperature of the oceans, the "consensus" that appears to exist from the number of scientific articles,...

By the way, the ozone hole 2006 was the biggest since the measurements began in 1979.

12 October 06 - The sun, cosmic rays, end the climate on earth: Svensmark's Sky-experiment and Svensmark's comments. (source: Junkscience dated 09 October 06)

Update 02 November 06 - Fair and very in-depth discussion at RealClimate.

24 September 06 - GISS-temperature data from the first 8 months of 2006 show this year will be about 0,15°C cooler than 2005. It is very likely 2006 will not break the year temperature record. See also Solaemon of 11 April 2006.

20 September 06 - Though the 2006 hurricane season a much less active one than last year's, the last few days were showing 2 prominent hurricanes in the Atlantic Ocean. Gordon (the most northern one) and Helene both reached Category 3.

12 August 06 - The most recent developments of the the ozone hole above Antarctica can be followed at the website of NASA's Ozone hole watch.

13 July 06 - Some FAQ on global warming. (source: Junkscience)

9 June 06 - The current temperatures in the Atlantic Ocean and in the Caribean seem to be significantly lower than a year ago. This would mean less and less intense hurricanes than in 2005. (bron: Junkscience)

25 May 06 - Belgium has taken a cold start in 2006. The average temperature was about 0,5°C lower than the longterm average in Uccle (since 1833). Especially the difference with the average temperature of the last 2 decades was noteworthy: Over 1,5°C lower! One has to go back all the way to 1987 to find a colder first 4 months.

25 May 06 - More factors than the seasurfacetemperature seem to determine the number of hurricanes and cyclons.

25 May 06 - ESA's brushfire maps are now online. A quarter of the reported events are false-calls.

04 May 06 - On May 2nd, the ice of the Tanana river broke up. That's about 2 days earlier than average, but 4 days later than last year. This continues the decreasing trend of the last few years (later break-ups). A graph was added showing the number of years versus the day of year during which the river ice gave way. There is a clear displacement during the last 30 years, albeit not spectacular (only about 6 days earlier). The up and down movement correlates well with the evolution of the AMO, but clearly other (natural) factors are also at play (e.g. El Niño).

21 April 06 - C-16 iceberg rams Drygalski ice tongue.

11 April 06 - Based on the GISStemperature data of the first 3 months of 2006, there is a strong indication 2006 will be 0,1 to 0,15°C cooler than 2005. The difference between the prediction based on averages between 1985 and 2004, and those between 1880 and 2004, is at this moment about 0,1°C, but will gradually decrease as additionnal data will become available. 2006 thus seems to be heading for an average global temperature deviation of about +0,55°C, compared to last year's +0,7°C. The final deviation for 2005 was +0,76°C. A deviation of +0,55°C is of course still quite high, and comparable to previous years (2001, 2004). It seems nonetheless that 2006 will not become a record-breaker. After summer, things will be more clear.

21 March 06 - About ice - When will the ice of the Tanana-river break? Last year, this happened on 28 April, 6 days earlier than the average. Many see in this ever earlier break-up a prove of the warming climate, yet a couple of parameters have to be taken into account. See also Solaemons of 29 April 2005 and before.

It's also almost certain that there will be no 11-city race this year. The last of this famous iceskating race in the Netherlands dates already back from 1997. However, this is no reason to point to global warming as the cause. Since its official start in 1909, this race has only been held 15 times: in 1909, 1912, 1917, 1929, 1933, 1940, 1941, 1942, 1947, 1954, 1956, 1963, 1985, 1986 and 1997. Remarkable is the 22 year raceless stretch between 1963 and 1985, when the global temperature was significantly lower than now in the 21st century. Also, there was a race in 1947, when there were several heatwaves during that summer. This is an indication there are probably other factors in play than just the climate.

A similar reasoning for the freezing of the Thames (London), as recently discussed on Realclimate. For the period of 1400-1831, these occured in 1408, 1435, 1506, 1514, 1537, 1565, 1595, 1608, 1621, 1635, 1649, 1655, 1663, 1666, 1677, 1684, 1695, 1709, 1716, 1740, 1776, 1795 and 1814. Contrary to Realclimate's conclusions, there seems to be reason to believe the 17th century was much colder than those before and after. 10 out of the 23 freezing-ups occured in that century, which is quite out of proportion. After 1831, the Thames has never frozen up again in London, but this has possibly to do with the increasing embankment of the river.

Above elements indicate that the freezing-up of rivers depends quite on local circumstances, and much less on climate changes.

1 March 06 - The Royal Meteorological Institute of Belgium announced today that the month of February was with only 29h55m of sunshine, the darkest since the start of the measurements in 1887 (normal: 73h!). The temperature also stayed below the average, but nothing abnormal here.

24 February 06 - Solar flares altered Mars'atmosphere. (Source: Universe Today)

24 February 06 - Solar cycle delays recovery ozone. (Source: Geophysical Research Letters)

24 February 06 - ENSO influences NAO. (Source: Geophysical Research Letters)

18 February 06 - Recently, Science published an article (Rignot and Kanagaratnam) announcing Greenland's glacier ice was accelerating its discharge into the ocean (NYTimes transcript). Reactions on Junkscience (16 Feb 2006), but especially a very good analysis at TCSDaily: Ice Storm. AMO was also included in my simulation of the global temperatures at Junkscience (June 2005).

13 February 06 - An article in Science written by Briffa and Osborn seems to indicate that the global warming in the last 100 years is much bigger than that during the Middleages. Reactions on Realclimate and Climate Audit. Once again, it looks like this is just another article using mostly the same proxies as Mann et al., making the same errors, and basically this means the discussion is far from over.

6 February 06 - Is a weak La Niña developing in the Pacific? For influences on the weather, see El Niño and La Niña.

2 February 06 - With 1,7°C, January 2006 had a normal average temperature for Belgium. However, we have to go back to 1997 and 1987 for finding even colder January months. The temperature was 0,9°C under the 1833-1985-average.(Sources: GISS, KMI ).

2 February 06 - Frozen tsunami (Source: Junkscience).

24 January 06 - Less sunlight, yet increasing temperatures? (Sources:, Junkscience).

14 January 06 - According to GISS, 2005 was the warmest year since measurements began in 1880. My comments can be found under Prediction global temperature deviation 2005.

13 January 06 - A new methane source? BBC News, Eurekalert,Nature (abstract), and some comments from Realclimate. To be continued, for sure!

10 January 06 - Electrical hurricanes (source: Science at Nasa).

5 January 06 - A couple of days ago, Our national broadcast cooperation VRT reported 2005 to be the 11th warmest year in Belgium since measurements started in Uccle in 1833. That makes it part of the group of warm years our country is experiencing since about 20 years now.

It was almost in triumph that VRT concluded the warming trend of the climate is a fact (this was confirmed by a spokesman of the Royal Meteorological Institute).

Once again, VRT missed the point of the whole climatic debate. As the graphic underneath clearly shows, there is no doubt temperatures in Belgium are increasing, even when taking into account the urban-heateffect. In fact, temperatures increased by 1,5°C over the last 20 years, of which more than 1° in the period 1986-1990 alone! But VRT forgot to mention there is no causal relationship with the supposed manmade (anthropogenic) warming (essentially by the emission of greenhousegases). The graphic is clear: In the 1930's and 1940's, temperatures in our country were comparable to those of today, but the CO2-concentration at that time was only 307, where now it is 377!

31 December 05 - Greenland melting faster? (Source: Universe Today), will most of the permafrost have thawn by 2100? (Source: Eurekalert), or have we seen it all before? (Source: Junkscience).

25 November 05 - The singing iceberg (source: CNN).

19 November 05 - The article Is the Sun heating up? (source: Earthfiles, interview with Sallie Baliunas) deals with the relatively high solar activity of the last few years, putting it in perspective against that of the last couple of centuries, and evaluates possible connections with climate changes on Earth and on other planets of the solar system.

08 November 05 - Ice:

29 October 05 - It is "unusually" warm in Belgium. Maximum temperatures reach 23°C. About 10 years ago, the Royal Meteorological Institute published a book "Climate averages and weather extremes in Belgium" (data from 1833 till 1990). For the month of october, it then appears that from 1941 till 1990 1 out of 3 October months contained at least 1 week with an average temperature of 18°C or more. 1 out of 5 even contained at least one day with at least 25°. On 27 October 1937, Uccle registered 24,1°C. Other late october highs were in 1980 and in 1968. In the period 1833-1900, 8 October months had at least 1 day with 23°C or more. From these measurements, it may be clear that current temperatures may be somewhat unusual, but certainly not exceptionnal. Clearly, these high temperatures were also present long before any potential human influence on climate. By the way, In Belgium, till the end of November, a daily -but admittedly exceptionnal- temperature of 16°C can be registered.

23 October 05 - To put the 2005 Atlantic/Caribbean hurricane season (up to and including Wilma) into perspective (all data from the Unisys website):

The above graph depicts the total number of hurricanes per year and per category (5 being the strongest). Notice the strong year to year variation. 2005 is the first year to show 3 Cat 5 hurricanes in 1 year, and equals 1999 for the most Cat4&Cat5 hurricanes (5). Not being over, 2005 is also (already) the year with the most hurricanes since 1851, together with 1969 (12).

The above graph depicts the 5-year averaged number of hurricanes per year and per category. Notice the current number of hurricanes is comparable to the periods around 1951 and 1891, and its number Cat4&Cat5 to 1960's. It is interesting to see how the numbers quite suddenly increase from the early 90's, after four decades of decline! This is completely contradictory to the claimed connection with the anthropogenic (human caused) CO2-increase.

Finally, the foregoing graph shows the 5-year averaged Hurricane intensity (summed over all categories) versus the 5-year averaged number of strong hurricanes (Cat 4 & Cat 5). The upperleft cluster of datapoints reflects the hurricane seasons since 1997. The current number of strong hurricanes is comparable to that of the 60's (upper right cluster), and with the 2004 & 2005 seasons, its intensity apparently moving towards this cluster. This means current hurricanes are getting stronger, but nothing unusual as this has happened before.

23 October 05 - A smaller but thicker Arctic ice cap?.(Source: Reuters)

23 September 05 - Mayfield et al.: String of intense storms is part of normal cycle.

16 September 05 - Our national broadcast center VRT reported on the increasing number of hurricanes during the last few decennia. This was based on an article in Science (abstract, article). I forwarded some comments to the VRT:

Other comments can be found on the website of Junkscience, dealing with hurricanes that have made landfall in the US.

12 September 05 - Methane evolution over last 2000 years: Interesting results, wrong conclusions. One of the main results is that current methane levels are the same as a thousand years ago. In stead of trying to link this to human activity, an entirely natural evolution seems much more likely.

04 September 05 - Comments on Hurricane Katrina on Real Climate and Indur M. Goklany.

26 August 05 - Predictions for the coming winterseason based on the NAO-index.

15 August 05 - In the most recent Science-issue, researchers reported about corrections on measurements made by satellites and weather balloons. The changes are small, and within the old error-margin, yet they are closer to the currently measured and modeled temperature series. The trend now is about 0,12°C/decade (from 0,085°C), but still is quite below the surface thermometer readings of 0,2°C/decade. I do want to point out that all measurements started at the end of the last relatively cool period, and that none of the calculated trends is anywhere close to the longterm (centennial) temperature evolution. Source article at TechCentralStation, comments at Realclimate ([1],[2]), various comments at Climate Audit, also at UKWeatherworld and at FOX news.

15 August 05 - Antarctic Sea Ice may be increasing. (Universe Today)

11 August 05 - The WWF once again got all media-attention by publishing a doom article on increasing summer temperatures in European capitals. Graphic underneath (datasource: NASA/GISS) shows the elephant. In Uccle (Brussels), the average summer temperature has increased by 1,2°C compared to the period 1970-1975. The evolution is representative for the other European capitals, with Madrid (increase by 2,2°C) topping the list. The WWF does forget to mention that the entire increase actually occurs in a period of only 7 years (1986-1993). Both before and after this period, temperature remained quite stable in Uccle.

According to the WWF, the main cause is anthropogenic global warming (CO2-emission). If no immediate measures are taken, then...doom...more doom...even more doom... The Kyoto-protocol will not be sufficient: measures need to be even more stringent!

Well, before it comes to that, let's put the recent increase in summer temperatures in perspective by using the temperature series that stretch back all the way till 1833. As the graph underneath shows, this most recent temperature increase now only is as big as a mouse: it disappears in the waxing and waning of temperature as observed in the last 170 years. The summer temperatures in Uccle now are on the average of the same level as those of 1930-1950 and around 1858. Occasional "super" summers clearly peak above this average evolution: most recently there were 2003, 1995 and 1976, but we also had 1947, 1911 and 1846. Sudden temperature variations occur regularly. Aside 1986-1993 (+1,8°C), there were also noticeable increases in 1924-1934 (+1,6°C) and in 1843-1846 (+0,8°C). Sudden decrease have also happened, particulary the period 1949-1955 (-1,8°C). Finally, the WWF also forgets to mention they started their measurements in a rather cold summer period, but then: if they would have compared current summer temperatures with those of the thirties, then there is certainly nothing abnormal to report?

10 August 05 - The new Antarctic Ozone hole season has started out quite big. It remains to be seen if this evolution further continues.

08 August 05 - Climate evolution in Europe

29 July 05 - Severe flooding in India after the wettest monsoon ever caused by (anthropogenic) global warming? No (yearly variations are normal), no (monsoon is connected to El Niño) and no again (large areas in India have not gotten enough rain)! Online monsoon-monitoring shows total rain amounts for India over the last 7 weeks are perfectly normal!

21 July 05 - Interesting developments in the continuing discussion on the reliability of Mann's hockey stick. Joe Barton, member of the American House of Representatives, had written some letters to Mann and his 2 colleagues asking -amongst other things- about the availability of data and source codes used and that resulted in the hockey stick. The responses of Mann, Bradley and Hughes are located at Realclimate's website, containing also some reactions on Barton's letters of other institutions. "All of a sudden", there has been a "recent" release of additional "codes", and the first commentaries of McIntyre and McKittrick can already be found on their website (Climate Audit: 1, 2, 3, 4)

21 July 05 - Interesting article on the "record"temperatures (50°C and more!) that are scorching the southwest of the United States at the moment. It is noteworthy because the mentionning of the influence of the Urban Heat Island.

16 July 05 - Some links to articles:

02 July 05 - I added a few words on the prediction of the global temperature deviation for 2005 under the Climate topic.

02 July 05 - France will be the site for the new international nuclear fusion-reactor, but some important concessions had to be made to Japan.

24 June 05 - After a critical article in the Wall Street Jounal on anthropogenic global warming, there is once again a heated debate between the Real Climate and the sceptics of Climate Audit. No new elements were presented, only an overview of all problems with the current "consensus" in climate research.

12 June 05 - After evaluation, my Global Climate Model (GCM) has been incorporated by the Junkscience-team. The yearly global temperature is calculated using the number of days the aa-index passes certain tresholds, the ENSO-index (El Niño), major volcanic eruptions, AMO (Atlantic Multidecadal Oscillation), NAO (North Atlantic Oscillation), CO2, and the Urban Heat Island Effect. Absolute values show a 0,2° maximum deviation (correlation 83%) to realworld temperatures; using 5-year averages the deviation is only 0,1°C (correlation 94%). The disadvantage of the model is that it offers no explanation for a posssible interaction between the parameters. Hence, it is very likely this model means for global temperature what Titius-Bode's law is for the planets: a very nice statistical approach, but without solid scientific meaning. The coming years will put this model to the test.

11 June 05 - This week featured back-to-back articles on CO2. Real Climate proved all CO2-emission is manmade, while Climate Audit shows this anthropogenic contribution to the natural greenhouse effect is insignificant (0,0006% of the total atmosphere, ref. article by G.W.Burrows).

11 June 05 - This article presents a new theory on glaciers' dynamics. Based on pieces of wood carried along and deposited by the glaciers in the Alps, the Swiss scientist Ulrich Joerin has determined that since the end of the last ice age these glaciers have expanded and retracted about ten times. The current melting is not unusual in view of the Little Ice age (around 1650), but further research is required to evaluate the anthropogenic influence, and to refine some data.

28 May 05 - With this article, Real Climate provides a fair discussion on the retreat of the tropical glaciers.

21 May 05 - Climate

21 May 05 - Hurricanes - NOAA predicts a (slightly) higher than average hurricane season for 2005. There are 7 to 9 Atlantic hurricanes expected (during last 30 years, just over 7). Half of those are expected to grow into a major hurricane (category 3 or higher), clearly above the 30-years average (2,3), and more in line with the last 10 years (3,8). See Solaemon of 04 May 05 en The climate on earth, as well as Climate Audit (10 Jun 05).

Meanwhile, hurricane Adrian got headlines because of its unusual direction (easterly, in stead of westerly). Yet, this movement is less abnormal than is claimed: hurricane Kenna (2002), tropical storm Rosa (2000) and hurricane Rick (1997) have all done it before. See Unisys for recent updates.

21 May 05 - Volcanoes - Interesting article on temperature sensitivity of the earth's atmosphere after a volcanic eruption, as well as an update about Mount St-Helens.

13 May 05 - This week saw gun powder and canon fire in the domain of climatic reasearch once again.

05 May 05 - Some more comments on the "smoking gun" of earth's energy imbalance (Solaemon of 30 April 05). The "pro's" of Real Climate versus the "sceptics" Lubos Motl and Climate Audit.

30 April 05 - Both BBC and CNN report about a group of scientists (Hansen et al.) claiming to have found the "smoking gun" about a human induced (anthropogenic) global warming. Measurements of ocean temperatures seem to indicate that the earth's atmosphere is absorbing 0,85 W/m2 more than that it radiates back into space. This imbalance apparently can only be produced by greenhouse gases, and the already stored energy in the oceans would result in an extra global warming of 0,6°C by 2100, even if the emission of all GHG could be halted immediately. However, according to the World Climate Report, the figures published are much lower than those currently used. The warming of the earth thus seems to be much less sensitive to the extra absorbed Watt/m2 than originally thought, possibly because the models assume a much higher increase in [CO2] than measured so far, and/or because the measurements span a period of only 10 years (1993-2003, weakness noticed by Hansen), including a very powerful El Niño-event (NOAA's El Niño's Theme Page). On top of this, there are a number of other parameters of which the influence is not known well enough, like e.g. the solar activity, aerosols (dust,...) and the heat convection in clouds. Hence, it remains to be proven that the current warming can be attributed for the major part to the emission of anthropogenic greenhouse gases. Further comments provided by World Climate Report (10 May 2005).

04 May 05 - The hurricane season hasn't even started yet, but already a scary cover headed the 21 April edition of Nature: 4 super hurricanes surrounding tiny Florida. Reactions already on World Climate Report, and on Real Climate. An excellent analysis on the why of last year's hurricane season was already published in December 2004 by EOS. It may be clear that there are not more hurricanes now than "in the past", and they are also not more powerful. See Solaemon's topic on hurricanes.

29 April 05 - Yesterday, the ice on the Tanana-river broke. That's 3 days later than last year's (2004 was a leap-year), but 6 days earlier than the average. Is this telling us something about climate warming? No (see also Solaemons of 01 and 22 April). 46 winners share the $285.000 jackpot.

22 April 05 - Resistance is futile: The day the ice in the Tanana-river (Nenana, Alaska) will break up, is near (See also Solaemon of 01 April). Since records started in 1917, this occured somewhere between 20 April and 20 May, with 04 May as the average. This graph shows the yearly evolution of this event. A slight increase (earlier break-up) is noticeable (7 days per century), but the correlation is far from significant (r2 = 9% only), hence the link with climate warming is not valid. Besides temperature, also the riverdynamics (precipitation), the urban heat effect and the ocean currents (Pacific Climate Shift, since around 1975) play their role and make this phenomenon rather a true lotery than a proof for man-induced global warming. Up-to-date information can be found on the website of the Nenana Ice Classic.

01 April 05 - When will the ice in the "Tanana"-river (Alaska) break up? And is this date of break up a sign for local climate change? More on this can be found on the websites of Fairbanks and John Daly.

17 April 05 - About gamma rays

17 March 05 - Some climate topics that were discussed the last few days:

18 February 05 - An answer on the criticism of McIntyre and McKitrick was published today on the Realclimate's website ("Dummies guide to the latest hockey stick controversy" of 18 February 2005). Their argumentation brings nothing new, and actually stops where the article from Natuur&Techniek continues for another 2 pages (ref. Solaemon of 28 January 2005). The question about the reliability of the "hockey stick" is essential: if can be proven that other warm periods have occured during the last millennium, then this automatically means that greenhousegases are not necessarily the cause of the currently observed global warming, with all the consequences on the measures to be taken with regard to the CO2-emission.

16 February 05 - The Kyoto-protocol has come into force. My vision has been added to this website.

28 January 05 - This article discusses another clash between defending and sceptic scientists of a human-induced global climate warming. This article, by the hand of Marcel Crok, appeared in the February-issue of the Dutch magazine Natuurwetenschap en Techniek.

15 January 05 - Comments from the KMI (Royal Meteorological Institute of Belgium) on the warm first decade of January 2005. Temperatures were very abnormal, however these conditions also occured during e.g. 1921. Also no temperature records were broken: the highest day-temperature for January dates back already to 1947. The complete article (in Dutch) can be read at the site of the KMI. In conclusion, there is no link to the global warming.

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12 September 2013 - Voyager 1 has left the solar system! - Based on the effect of coronal mass ejections on the far edge of our solar system, NASA scientists have determined that Voyager 1 entered interstellar space around 25 August 2012. The whole story is at Science at Nasa. A more cautious point of view can be found at arXiv.

31 August 2012 - I've updated the page that provides an overview of all satellites monitoring the solar-terrestrial relationships, as well as the page that provides an overview of all white light flares (WLF).

09 June 2012 - I added a list of satellites (past and still operational) involved in the research on solar-terrestrial relationships on my Solar Cycle Page.

05 June 2012 - Resistance is futile! The Venus transit is inevitable, as shown in this PROBA-2 image. The tiny dark blob in the upper left corner, at the edge of the solar corona, depicts Venus on its way to its second 21st-century transit across the solar disk. It is better visible in this contrast-enhanced image at the Proba-2 Science Centre and also in the GOES-15 SXI images. It also means Venus will be visible for a while even after the transit will have ended. The transit will be monitored by various satellites and earth-based observatories like GONG (H-alpha!), ISS (NASA), Proba-2, SDO,... HAPPY VENUS TRANSIT!!!

Update 07 June 2012 : I added a YouTube movie of this event based on a compilation of earth-based and satellite imagery.

13 December 2010 - No more solar wind for Voyager I spacecraft. But it is still not in interstellar space... yet!

02 December 2010 - SOHO celebrates 15 years. Congratulations to the entire team that made (and still is making) this the greatest and most successful solar mission ever! SDO and others can stand on the shoulders of a true giant!

05 May 2010 - New solar astronomy magazine online - The first issue of Solar Observer is now online. It's a magazine that wants to cover all areas of solar astronomy, and for this huge scope it can count on contributions of both amateur and professional solar astronomers. It therefore targets a broad range of readers, from the very beginner to the advanced astronomer. If this level of science (no maths!) and number of articles can be maintained, it may quickly become the Sky & Telescope of solar astronomy magazines! Congrats to the editorial board!

29 Jan 2010 - First results of the PROBA-2 satellite. All data will be freely available tot the public at their Science Center, which also hosts a very nice Outreach-site (Suntrek).

Meanwhile, the Solar Dynamics Observatory is getting ready for its "no-earlier-than-09-February" launch. See Universe Today for a movie of its mission.

20 Jan 2010 - I've "rewired" the entire website. That way, I hope it's easier to use. More to come.

15 Jan 2010 - Giant ribbon at the edge of the solar system

12 November 2009 - Proba-2: Everything is going just fine!

10 June 2009 - Passing away of Jack Eddy, famous for his research on the Maunder Minimum. Beautiful article on Wattsupwiththat. Also, an online petition has been opened to call the next significant solar minimum the Eddy Minimum.

23 December 07 - Voyager 2 passes the termination shock of our solar system. See also the article by The Planetary Society.

22 September 06 - Voyager keeps surprising.

24 August 06 - Pluto is no longer a planet. The decision is finally taken. The definition of what a planet is, could have been a little bit more concrete though.

25 May 06 - SOHO-mission extended till December 2009.

25 May 06 - News from the outer regions of our solar system.

19 November 05 - Coming soon: the Sun in 3D: Status of the STEREO-mission, with launch scheduled for spring 2006. (John Hopkins University)

23 October 05 - The Japanese Space Agency JAXA announced a few weeks ago that Yohkoh, a satellite observing the Sun in X-rays during the nineties, re-entered the earth's atmosphere on 12 September burning up above southeastern Asia. Yohkoh was already inactive since 14 December 2001, and leaves the scientific community an impressive legacy.

12 August 05 - Science announced that from the S-33-isotope, found in meteorites, scientists have concluded that the sun was radiating much sooner than thought so far. This may have influenced the development of micro-organisms on earth. Article and comments on the website of Sky & Telescope

31 July 05 - Most recently discovered Kuiper Belt Object is bigger than Pluto, and another KBO is just a bit smaller than Pluto. Possibly, 2003 UB313 will be considered for the 10th planet of our solar system.

28 May 05 - It is now certain that the Voyager 1 spacecraft has passed the termination shock of our solar system. The termination shock is the area where the supersonic solar wind slows down to subsonic speeds. The spacecraft is now in the heliosheat, an area where the magnetic field of the solar wind is still stronger than that of interstellar space, but gradually weakening. The place where the two become equally strong, is called the heliopause and marks the final frontier of our solar system. Voyager 1 is expected to reach this border before 2020.

23 April 05 - A brief article over the time-distance between sun and earth was added under the topic "The Sun: theory". Also, a few links to H-alpha observers were added under the topic "The Sun: observing".

22 April 05 - On the origin of our solar system

09 April 05 - Updates on future solar missions - Links to the websites of Solar-B (Japan, NASA, UK) and Solar Orbiter (ESA). Solar-B is the successor of the very succesful Yohkoh-satellite and is scheduled for launch in September 2006. The Solar Orbiter is going to observe the Sun from very close (only 30 million km, that's within Mercury's orbit), which should produce solar images with the highest resolution ever. Moreover, the orbit's inclination during the 5-year-mission will steadily increase to about 30 degrees allowing a better view on the solar poles. As a consequence, the Solar Orbiter can be considered as the successor of SOHO and Ulysses. Unfortunately, the mission's start is only foreseen for 2013 (if everything goes fine).
In February 2006, STEREO (NASA) should be launched. This mission consists of 2 satellites: one that is heading Earth, and the other will be trailing Earth. This configuration should allow for the first 3-dimensional images of the sun, and it should also give scientists an opportunity to better study the CME's (Coronal Mass Ejections). Finally, there is also the Solar Dynamics Observatory, NASA's successor for the SOHO-satellite and of which launch is foreseen for April 2008.

01 April 05 - Recent observations with the SOHO-satellite (SWAN) have shown that the heliosphere is distorted by the galactic magnetic field. It was also confirmed that the Voyager 1 is very close to this outer limit of our solar system.

25 March 05 - Seems like NASA will pull the plug out of the very succesful TRACE solar satellite. Due to budgetary cuts, this may already happen in September 2005. See the message from the American Astronomical Society / Solar Physics Division, that, on top of all the TRACE-achievements, also discusses a number of upcoming solar missions.

16 January 05 - David Lunt, founder of the wellknown Coronado, has died. Because of Coronado, amateur solar-observers were finally able to buy excellent and easy-to-use H-alfa instruments at a reasonable price. Because Coronado was sold to Meade in October 2004, the Coronado-telescopes and filters will remain available to the solar observer. More info at Sky & Telescope.

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31 December 05 - Buffy, the exoplanet. (Source: Astronomy Now, 14 December)

02 July 05 - Some articles:

18 June 05 - A new type of exoplanet was discovered by Marcy & Butler around the star Gliese 876. The planet is only 7 times heavier than Earth, and possibly consists mainly of rock. Unfortunately, its distance to the parent star is only 3 miljoen km, making it too hot. Because of the newly applied techniques, the researchers think the discovery of more earthlike exoplanets is just around the corner.

21 May 05 - Exoplanets

17 April 05 - The world of exoplanets

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10 March 08 - The Earth has an inner inner-core.

25 August 07 - Interesting info and movies on sprites were published on NASA's Spaceweather website.

31 December 05 - Leap second in 2005. (CNN)

31 December 05 - The mystery of Mount St-Helens. (CNN)

11 March 05 - Mount St-Helens burps - No harm done, but an impressive ash-and-steam plume and some spectacular images.

13 December 05 - Northern lights on the move. (Universe Today)

13 October 05 - Alaskan volcanoes show signs of unrest. (CNN)

13 October 05 - Evolution Monsoon in India and Antarctic Ozon hole.

29 July 05 - As of August 1st, the evolution of the Antarctic Ozon hole can be daily monitored at TOMS.

29 July 05 - Dust from the Sahara has crossed the Atlantic to produce red sunsets (and sunrises) in the US: CNN-article and online dust-monitoring.

16 July 05 - Earthfiles reported that near Santa Barbara (California, USA), some very hot, non-volcanic rock has been found. The over 300°C hot material covers an area of 17 acres, and is still hot enough to start brush fires as it did in 2004. The reason for the heat generation is believed to be an underground exothermal reaction. The whole topic made me think of the Smoking Hills (also here) of Canada's Cape Bathurst.

16 July 05 - Some links concerning every sailor's worst nightmare: Freak waves (No Tsunami's!):

24 June 05 - Both the night from 14 on 15 as from 19 on 20 June, spectacular displays of noctilucent clouds were visible from Belgium. Images and comments can be found on the sites of VSW MIRA, VVS, KNMI, Spaceweather and Science@NASA. In 2003, NASA published an article on the possible influence of Space Shuttle-launches on noctilucent clouds (more launches = more and more intense clouds).

18 June 05 - Some significant earthquakes occured this week. A 7,8-tremor on 13 June made several casualties in Chile. The whole week was a rumbling for Californians. The strongest quake was a 7,2 in the Pacific. Though the quakes made no victims, they do increase nervousness with locals.

11 June 05 - The Colima ("Volcano of Fire", Mexico) roars (already for a while). Live webcams at Colima Volcanologic Observatory.

28 May 05 - Scientists find indications for the influence of solar activity on whale strandings.

21 May 05 - Antartica - The giant iceberg B-15A, the "Conan" of all icebergs, is ready to behead yet another glacier (Aviator Glacier), just one month after the Drygalski ice tongue. Updates on ESA Earth Watching, and an article is on Universe Today.

22 April 05 - Images of the Envisat (ESA) show the giant iceberg B-15A has collided with the Drygalski ice tongue around mid-april, and has torn off a 5 km2-big chip. More images as well as animations can be found on Antarctic Meteorological Research Center. B-15A is the largest remnant of the giant ice plate that broke loose of the Ross Ice Shelff in March 2000.

09 April 05 - Antartica - The 2500 km2 big iceberg B-15A, which was on a collision course with the Drygalski ice tongue in late january, now seems to move away from it. Magnificent images can be found on the website of Envisat (ESA).

19 January 05 - Antartica - Beautiful satellite-images of an iceberg, the size of Long Island, bumping into the south polar icecap.

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