Predictions for Solar Cycle 24




Rank Name Type Technique Tbegin E.M. Tmax E.M. Rmax E.M. TPred Ref. Remarks
1 Schatten physical SODA-index Nov 07 12 Jan 13 12 80 35 Nov 05 (1);(2); (3) (3): Update by Pesnell and Schatten; May 07
2 Sello stat+phys Nonlinear dynamics applied on SODA-index - - Apr 11 - 96 25 Jul 03 (1) -
3 Svalgaard physical Polar magnetic field - - Jun 11 12 70 2 Jan 05 (1);(2); (3) -
4 Choudhuri physical Polar field & randomness integrated in dynamo model Jan 09 12 Jun 12 12 75,0 2,7 Mar 07 (1); (2); (3) -
5 Lundstedt stat+phys Lund Solar Activity Model (Neural network+Physics) - - - - 85 25 Jun 05 (1);(2);(3);(4);(5) Own extrapolation
6 Dikpati physical Meridional flow & magnetic memory Dec 07 3 2012 - 169 12 Mar 06 (1);(2);(3); (4) Update Aug 07 confirms initial results of Mar 06
7 Hathaway stat+phys Meridional flow (sunspots) & Trise-Amplitude relation Dec 06 3 2010 - 145 25 Mar 06 (1);(2);(3);(4) -
8 Maris physical Flare energy release during descending SC-phase - - - - Low - 2003 (1);(2) Max. est. 70
9 Badalyan physical Coronal Green line (10 years in advance of R) Jan 07 12 Jan 11 12 50 - Dec 00 (1) -
10 Duhau stat+phys Non-linear model on Rmax en aa-min - - - - 87,5 23,5 Mar 03 (1) -
44 De Jager, Duhau stat+phys Non-linear dynamo model and longterm oscillations in Rmax and aamin Jun 08 8 Jan 2014 6 68 17 Dec 08 (1); (2) -
11 Clilverd physical Variation of the atmospheric cosmogenic radiocarbon - - - - Low - 2004 (1);(2) Max. est. 70; Symposium
12 Kane stat+phys Precursor method based on aa-index at SC-minimum - - - - 124 26 Jul 07 (1) Upper limit= 142 +/- 24 if no correction for 3nT
13 Rabin stat+phys Geomagnetic precursor method based on aa- and Ap-index - - - - 115 30 May 07 (1) Symposium
14 Hathaway stat+phys Geomagnetic precursor method based on aa-index - - Jan 11 12 160 25 Dec 06 (1);(2)(3);(4);(5) -
15 Dabas et al. stat+phys Geomagnetic precursor method based on Ap-index (SC17-23 only) - - Dec 11 4 124 23 May 08 (1);(2) Max. SC24 45+/-4 months after SC Min.
16 Jiang, Chatterjee, Choudhuri physical Poloidal field and high diffusivity in convection zone - - Sep 13 18 85 10 Feb 08 (1);(2) Own extrapolation from Fig. 16
17 Hill physical Helioseismological observations - - - - Weak - Jun 08 (1) Est. 80+20
18 Wang et al. statistics Statistics based on previous, cherry-picked solar cycles Oct 07 5 Jun 11 5 119,5 12,4 Nov 08 (1) SC Tmax 44+5 months after Tmin
19 Pishkalo statistics Statistics on sunspotnumber parameters - - May 12 1 110,2 33,4 Nov 07 (1) -
20 Kilcik et al. statistics Nonlinear methods (Hurst exponent and Sugihara-May algorithl) - - Dec 12 - 87,4 - Dec 08 (1) Preprint Arxiv
21 Kane statistics Precursor SGN in 10°-30°N - - - - 130 16 Nov 07 (1); (2) -
22 Kane statistics Gnevyshev-Ohl-Kopecky rule and Three-Cycle-Rule (TRC) - - - - 132 36 Oct 08 (1) Large error! GOK predicts 106+42.
23 Kane statistics Cherry-picking of SC's total duration and Rmax - - - - 94 44 Feb 08 (1) Large error!
24 Tong Xu statistics Empirical Mode Decomposition and AR-model on sunspotnumbers - - Dec 11 12 112 8 Jun 08 (1);(2) Method predicts SC23-min in 2007
25 Gholipour statistics Spectral analysis and neurofuzzy modelling - - Jan 12 12 145 - Mar 05 (1) -
26 Kane statistics Spectral analysis Sunspots (Maximum Entropy Method and MR-analysis - - Dec 12 24 92 11 Oct 99; Nov 07 (1); (2) Update down from 105+9
27 Echer statistics Spectral analysis Dec 07 12 Dec 12 12 116 13,2 Jun 04 (1) -
28 Wang statistics Low and high rising velocity groups - - Mar 12 12 101,3 18,1 Jul 02 (1) -
29 Kaftan statistics Kinematical modeling of solar parameters Aug 07 16 Jun 12 14 163 37 2005 (1);(2) Updated
30 Euler statistics MSAFE (advanced McNish-Lincoln) Jun 07 - Mar 11 - 110,5 - Aug 04 (1) 50% percentile; NASA Report
31 Myung-Hee statistics Statistics + Odd-even cycles Dec 06 14 Nov 10 6 122 6 Sep 04 (1) Annual Rmax; NASA Report
32 Hathaway statistics Statistics on daily, monthly, yearly R < 07 - - - Large - Nov 03 (1) Max. est. 160; NASA Report
33 Ahnert statistics Statistics + Trise-Amplitude relation Jun 07 12 Nov 11 12 92,3 29,9 - (1) Own extrapolation from book
34 Chopra statistics Precursor of Ap & R - - - - 139,3 - 2005 (1);(2);(3) Tmax = Tmin + 52 ; Symposium
35 Lantos statistics Skewness solar cycle & odd-even cycles - - 2011 - 108 38 Mar 06 (1);(2) T est. = Jun 11
36 Kontor statistics Fourrier spectrum of Gleisberg and Schwabe cycles Jan 08 +7/-4 Dec 12 11? 87 12? Dec 08 (1) Incl. SC25 (low) ; Website; Update from Mar O6, with Rmax = 70
37 Clilverd statistics Medium- and longterm periodicities in C14 applied on Wolfnumber - - - - 42 34 Sep 06 (1);(2) Incl. SC25 (low)
38 Du statistics Inter-cycle analysis of extremums and ascending/descending phases Mar 07 7 - - 149,5 27,6 May 06 (1);(2) Incl. SC25 (High)
39 Baranovski statistics Non-linear dynamics and chaos theory - - Jan 12 12 80 21 2006 (1) Symposium
40 Javaraiah statistics Hemispheric Sunspot Area, North-South asymmetry, 44-year periodicity - - - - 87 7 Jan 07, Oct 08 (1); (2);(3) Update up from 74+10
41 IPS (not published) statistics Average of last 8 solar cycles Oct 07 6 Aug 11 12 134 50 Apr 07 (1) Website
42 Hiremath statistics Forced and damped harmonic oscillator (sinusoidal and transient parts) + AR-model Jul 08 2 - - 110 11 2006a; 2007; Jan 2008 (1);(2);(3) Incl. SC25-38; Update in 2008
43 Tlatov statistics Based on duration of preceding cycle - - Mar 11 8 110 27 Dec 07 (1) -
45 Uwamahoro statistics Neural networks based on R and aa-index Jan 08 - Jun 12 10 117,5 8,5 Dec 08 (1) Tsub>min assumed


Comments on prediction methods

The method by Li et al. (2005) and NASA/Technical Report on the use of the modified precursor method by Wilson and Hathaway (July 2008) were not inserted into the table because of the various predictions that were being made for SC24. Wilson and Hathaway were added as supplemental reference for Method 15 (Dabas).

Watari (December 2008) and Volobuev and Makarenko (April 2008) were not added to the table because of no clear predictions. Both do predict SC24-maximum will be lower than that of SC23.

Cameron and Schlüssler (October 2008, ArXiv) provide comments on the timings of minimum and maximum of a solar cycle and the implications on precursor methods. Vaquero and Trigo (June 2008) also caution on SC-amplitude prediction based on length of previous SC.

Pesnell W.D. (August 2008) provides an overview of comments on more than 50 prediction methods of the SC24-amplitude.

Obridko and Shelting (March 2008) also provide an overview and discussion of various prediction methods. Their paper uses also three different methods resulting in three different results for SC24-maximum, although in the medium category (80-120). Not included in table.

Of the 17 methods that have made a prediction of the timing of solar cycle minimum, only 7 have this timing still in their error margin (methods 1, 4, 27, 29, 36, 42 and 44).


Summary - Table

Type Tbegin E.M. Tmax E.M. Rmax E.M.
Physical Jan 08 10 May 12 14 83,2 13,6
Mixed (Dec 06) (3) Mar 11 8 117,1 25,3
Statistical Sep 07 10 Jan 12 11 112,2 24,0
Panel SC 24 LOW Mar 08 6 Aug 12 - 90 10
Panel SC 24 HIGH Mar 08 6 Oct 11 - 140 20


Summary - Chart


Summary - Comments

Above tables and chart reflect predictions for the upcoming solar cycle. Averaging all results, solar cycle 24 is expected to start late 2007 (+ 11 months) and reach a maximum monthly Wolfnumber of 107,0 +/- 22,5 early 2012 (+ 12 months).

There is however a strong divergence between the statistical and more physically oriented approaches. The first methods result mostly in an average to strong cycle, whereas the latter -upon 2 noteable exceptions- indicate a low to moderate cycle (taking the error margins (E.M.) into account). Moreover, Schatten, having predicted correctly the amplitude of the 2 previous solar cycles, now indicates only a low to moderate cycle. But Dikpati and Hathaway, having worked on the sun's internal plasma flows, come up with a large amplitude. Unfortunately, this method is new and still has to prove itself. During the prediction of the previous solar cycle, geomagnetic precursor methods (Thompson,...) were much hyped too, yet they failed significantly.

There is also the Gleissberg cycle, which shows up in Lundstedts method as well as in other statistical spectral and wavelet analysis. SC23 may be regarded in this context as solar activity in its early decline for decades to come.

One final note concerns low cycle amplitudes. Though Wolfnumbers may be low, this does not mean that overall solar activity will be low. Just as in SC23, despite low to moderate Wolfnumbers, occasionally big complex groups will be present and produce strong solar flares, even till long after sunspot cycle maximum. Thus SC24 evolution may be similar to SC23, but at an even lower activity level.


Last update: 09 February 2009

Physical/Statistical method 44 (De Jager/Duhau) and statistical method 45 (Uwamahoro et al.) were added. Statistical method 36 (Kontor) was updated. Of the 45 methods, 34 refer to a scientific paper, while 1 (method 20) is in pre-print. 4 predictions were made at a symposium (numbers 11, 13, 34 and 39), 3 in a NASA-report (numbers 30, 31 and 32), 2 come from a website (36 and 41), and 1 was taken from a formula in a book (33). Summary-chart was updated.

25 January 2009 - 10 new methods were added: Physical/Statistical method 15 (Dabas), physical methods 16 (Jiang) and 17 (Hill), and statistical methods 18 (Wang), 19 (Pishkalo), 20 (Kilcik), 21-23 (all by Kane), and 24 (Tong Xu). Updates were made to methods 6 (Dikpati), 26 (Kane), 40 (Javaraiah) and 42 (Hiremath). Of the 43 methods, 32 refer to a scientific paper, while 1 (method 20) is in pre-print. 4 predictions were made at a symposium (numbers 11, 13, 34 and 39), 3 in a NASA-report (numbers 30, 31 and 32), 2 come from a website (36 and 41), and 1 was taken from a formula in a book (33). Summary-chart, -table and -comments were updated. A section "Comments on prediction methods" was added right underneath the table.

08 September 2007 - Methods 2 (Sello), 12 (Kane), 13 (Rabin) and 43 (Tlatov) were added. Methods 1 (Schatten) and 4 (Choudhuri) were updated. Of the 33 methods, 21 refer to a scientific paper, while 2 (methods 42 and 43) are in pre-print. 4 predictions were made at a symposium (numbers 11, 13, 34 and 39), 3 in a NASA-report (numbers 30, 31 and 32), 2 come from a website (36 and 41), and 1 was taken from a formula in a book (33). Summary-chart, -table and -comments were updated.

28 April 2007 - Results of the 2nd meeting of the NOAA-panel: Press release and technical discussion and overview of the different prediction methods. SC23-minimum is predicted for March 2008 +/- 6 months. As solar activity further evolves, it will become clear whether SC24 is heading for a 140 +/-20 maximum in October 2011, or for 90 +/-10 in August 2012. Website with the proceedings and results of the panel can be found here.

13 April 2007 - Statistical method 42 (Hiremath) was added. This paper is in preprint. Summary chart was updated.

05 April 2007 - After a question by Dr. R. P. Kane, I've updated the entire reference-column. Links in bold (e.g. (1)) now refer to the true scientific paper. Of the 28 methods, 19 refer to a publication in a scientific paper. Choudhuri is still in the acceptance phase, while it is unclear which of the papers published by Lundstedt contains the actual prediction (85+/-25 is my own extrapolation from the average of solar cycles 12-15, corresponding to the result from the wavelet studies -WCMax and Timescale are about the same for 1900 as for 2000).
The other 9 methods can be summarized as follows: 3 are the result of a NASA-report, 3 come from presentations on a Symposium, 2 come from a website and 1 comes from a formula in a book. One method was removed, as it was actually a double (Gholipour Ali). Appropriate remarks were made in the last column. Summary-chart, -table and -comments were updated.

02 April 2007 - Statistical method 41 (IPS) was added. This method is apparently based on simply averaging the last 8 solar cycles. As this series contains the 4 most active cycles since 1750, the method virtually excludes the prediction of a possibly weak SC24. Notice also the very large uncertainty. IPS will adjust this average cycle as the new cycle unfolds. Summary-chart, -table and -comments were updated.

25 February 2007 - Statistical method 40 (Javaraiah) was added. Summary chart was updated.

21 January 2007 - Prediction 4 (Choudhuri et al.) was added. Rmax & Tmax are my own extrapolations.

01 January 2007 - Comments on Hathaway & Wilson (Prediction 14) were added (References, link (3)).

22 December 2006 - Prediction 11 (Hathaway) was added. Please note that maximum aa-i occurs in October 2003, at the time of the Halloween-groups. Summary-chart was updated.

11 November 2006 - Statistical methods 15 (Gholipour et al.) and 39 (Baranovski et al.) were added. Summary-chart was updated.

02 November 2006 - Predictions 37 (Clilverd et al.) and 38 (Z. L. Du et al.) were added. Prediction 29 (V. Kaftan) was updated. Charts and numbers were adapted accordingly.

Original: 07 May 06