The Earth



Contents

Introduction

Links

Climate


Introduction

This page provides some links to a variety of websites monitoring important phenomena on Earth, as well as links to and articles concerning the climate on Earth.

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Links

REAL TIME various imagery

Atmospheric phenomena

El Niņo

Ozon hole

Attention! - The first link deals with stratosferic Ozon that protects us against the harmful solar UV-radiation. The second link deals with troposferic Ozon ("smog"). The more stratosferic Ozon, the better; The less troposferic Ozon, the better. The danger treshold with troposferic Ozon is at 180 microgram per m3.

Hurricanes

Earthquakes

Volcanoes

Cosmic Radiation

Polar Ice

Magnetic poles

Solar Constant

The solar constant is the amount of solar energy arriving every second on 1 m2 of the earth's surface. It is measured especially by satellites like SOHO. The solar constant amounts to approximately 1366 W/m2. It varies by about 0,1% over 1 solar cycle, and exhibits some significant decreases when major sunspotgroups transit the solar surface (e.g. October 2003). These changes, occuring in the visual part of the electromagnetic spectrum, are considered to be not strong enough to have a significant impact on earth's climate. See also my study on the solar constant's evolution over the last decades under Solar Cycle.

Delta T

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Climate

Data and graphics

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Forums

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My vision on Earth's Climate

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My comments on media-coverage

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Articles

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Prediction Global Temperature deviation 2005

Updates

During the May-June timeframe, there was an interesting discussion on UKweatherworld concerning the value of the global temperature for 2005. High temperatures during the first few months this year had convinced NASA 2005 might become the warmest year on record. The forum participants decided to make a bet on how big the temperature deviation Tg would be.

Basing myself on GISS-data (monthly and yearly temperature deviations with baseperiod 1951-1980), I approached this problem statistically. For 2 timeframes (1880-2004, 1985-2004), I calculated the correlation between the average temperature deviation after x months of that year, and the final global temperature deviation for that year. From this, for each average x the difference was calculated between the real yearly temperature and the calculated one, as well as all the standard deviations. Using the developped formulas and standard deviations, table underneath was composed. Tg represents the predicted global temperature deviation based on the average deviation during the preceding months.

2005GISSPeriod 1985 - 2004Period 1880 - 2004
MonthT (°C)Tg pred. (°C)St.Dev. (°C)Tg pred. (°C)St.Dev. (°C)
Jan0,870,720,110,500,15
Feb0,750,670,090,520,12
Mar0,850,700,080,590,10
Apr0,780,720,070,630,08
Mei0,610,710,060,640,07
Jun0,740,720,050,660,06
Jul0,660,710,040,650,05
Aug0,720,730,040,690,04
Sep0,780,740,030,710,04
Okt0,750,750,020,73 0,03
Nov0,700,740,010,74 0,02
Dec0,640,750,000,75 0,00

Data change to previous predictions as a consequence of changes in the GISS data-file ("GISS T").

Based on the first 5 months of this year, the expected global temperature deviation Tg is 0,69 +/-0,06°C , or 0,62 +/-0,07°C pending the timeframe used. As a comparison: the biggest (positive) temperature deviation occured in 1998 (0,71°C). The last 3 years, Tg was resp. 0,70°C, 0,66°C and 0,60°. These are also - after 1998 - the 3 warmest years since the start of the measurements (1880). The temperatures thus far do not favor 2005 as a record year, but the record remains (remotely) possible of course. Rather, it looks like it's going to be a tight race with 2003 for the third place, with a probable temperature deviation between 0,62 and 0,69°C.

Noteworthy is also that, even when data are known for 11 of the 12 months, Tg still can differ by 0,02°C from the final Tg (in 1 out of 4 cases even more!). Finally, it needs to be emphasized we are talking fractions of a degree Celsius, that are based on data from a few thousand observation stations from all over the world and operating under various conditions (rural vs. urban, just to name one). So, one needs to be very careful with comparisons between the different years.

Update October 2005 - Looks like 2005 may become the warmest year on record (since observations in 1880), unless November and December become unexpectedly cold. The temperature evolution corresponds much better to the last 25 years than to the average since 1880.

Update January 2006 - According to GISS-data (Surface temperatures, no ocean-data), 2005 was the warmest year (0,75°C above the 1951-1980 average) since measurements started in 1880. It dwarfs with 0,04°C the previous recordyear 1998 (though uncertainty bars!) which was strongly influences by El Niño. A climatological discussion on 2005 by GISS can be found here. The mentionned figures take into account the ocean temperatures and other artifacts like urban heat effect (though it remains to be seen if sufficient corrections were made). Since 1900, global temperature has risen by 0,8°C: till 1940 an increase by 0,4°C, then a decrease by 0,1°C till 1975, and a subsequent increase by 0,5°C. This evolution is absolutely not running parallel to that of CO2 (see graph underneath), indicating other factors are at play than only hunam-produced greenhousegases. There is for example no word about the almost complete lack of La Niña years (see John Daly, ENSO) since 1975, or the unusually high solar activity since 1980 (the highest since the Maunderminimum and amongst other well visible in the geomagnetic aa-index). There is no doubt global temperature has increased, only about the reason there still remains controversy.

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Climate evolution in Europe (1881-2004)

In order to quantify temperature differences from the urban heat island effect, yearly temperature evolutions from 78 urban and 40 rural locations in Europe were analysed. All data used come from GISS.

Selection of the stations was performed as follows

Some peculiarities about these stations:

Chart (University of Texas) underneath shows the location of all urban and rural stations.

Table underneath summarizes some basic statistics about the stations.

CriteriaUrban stationsRural stations
Number of stations7840
Average number of stations6023
Stations with > 90% coverage357
Stations still reporting in 20056326
Average latitude of stations49,1°54,8°
Average longitude of stations12,3°12,4°
Average population1.135.0000

Charts underneath show some trending and longterm evolution of location, number of stations and population. Above mentioned station peculiarities are apparent. Population is average of numbers mentioned on GISS-site.

The temperature deviation was calculated as follows. Stations were subdivided in rural and urban exactly as mentioned in the GISTEMP station selector (column "Pop."). For each station, average temperature and standard deviation was determined over the entire period for which data were available. Next, per year, the difference between yearly recorded temperature and average was calculated and divided by the standard deviation. Then, again per year, the average of temperature deviations for all available stations was taken. Finally, a 5-year average was taken centered on the third datapoint. The result is a smoothed temperature evolution for European urban locations and one for European rural locations from 1881 to 2004.

Both charts show a warming trend, but the urban evolution is twice as pronounced and three times as significant as the rural. According to urban stations, Europe sees a warming of 0,67°C/century, whereas rural stations only show a 0,37°C/century. Both charts show the same standard deviation (about 0,7°C). Also the overall evolution is very similar. Both records start with a modest increase of about 0,5°C till 1930, followed by a quite sudden temperature increase of 0,7°C achieved by the late 30's. This heralds a period of cooling lasting till the late 70's, but which is much more pronounced in rural records (decrease by 1°C) than in urban (decrease of about 0,5°C). From then on, both series show an increasing temperature till present. This warming is much more clear in urban records (increase of 1,5°C) than in rural ones (increase of about 1°C). So from the rural-urban temperature records, 5-year averaged temperatures in Europe have increased by 1,4-1,8°C over the last 124 years. It is very interesting to see that these temperatures can swing by 1°C in just a few years (up or down, rural and urban; absolute temperature deviations even 2 degrees!), and that urban and rural spikes are very similar (e.g. down around 1940, up in the late 80's).

Overlaying both temperature profiles confirms the similar overall trend. Though current urban temperature is about a quarter degree warmer than the rural temperature, it appears that during the considered timeframe rural temperatures have occasionally been higher than urban ones. This has happened for several years, and independent of an average low or high temperature (e.g. around 1890, 1910 and during the 30's, when average temperatures were resp. cold, moderate and warm in Europe). The reason for these short- to mediumterm fluctuations is unknown.

Yet there is a trend discernable in the longterm delta's between urban and rural temperature deviations as can be seen on chart underneath. From 1881 till 1955, there is no trend in the delta, but for the period 1925 till present, there certainly is. One can conclude that since the mid-40's, the difference between urban and rural temperature deviations has been gradually increasing at a rate of 0,65°C/century. It will be interesting to see if this urban-rural delta will continue to increase: one might expect it will, in view of continued industrialization (building, industry & transportation).

Correcting the urban temperature deviation for this heat effect (I assume here explicitely that the difference is due to the urban heat island effect, and that the correction can be applied linearily), following revised charts are obtained. Note the corrected urban-rural delta now shows an increase of only 0,02°C/century for the entire timeframe examined, with no statistical significance at all (r2=0,09%), which is excellent!

Averaging the rural and corrected urban temperature deviations (OK in view of delta-results above), one obtains the final chart for European land temperature evolution from 1881 till present. The evolution shows an increase of 0,38°,C/century, but with a statistical significance of only 11%. This is logical in view of the ups and downs in temperature. The results says that -at least for Europe- the climate changes, but is not warming!

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