Global temperatures
Open Climate4you homepage
Recent global satellite temperature
Click here to view the recent (daily) global satellite temperature (AMSU-A) at various altitudes in the atmosphere.
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Indicate your preference as to oC or oF
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Then click 'Draw graph'
You will need to have a recent version of JAVATM installed on your computer to make use of this facility kindly made available by Dr. Roy Spencer and Dr. Danny Braswell. If you receive an error message after clicking 'Draw graph', try downloading the latest version (free) of Java from java.com.
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Recent land surface temperature
Land surface temperature 4 March 2010 (degrees K = degrees C + 273.15), at 02 and 14 hr (UTM-time), respectively. White areas are oceans or land areas without data. Map source: NOAA. Please use this and this link if you want to see the original diagrams (NOAA 18) or want to check for more recent updates than shown above.
Click here to see the recent sea surface temperatures.
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Estimates of recent global air temperature change
All temperature diagrams shown below have 1979 as starting year. This roughly marks the beginning of the recent period of global warming, after termination of the previous period of global cooling (from 1940). In addition, the year 1979 also represents the starting date for most satellite-based global temperature estimates. For the three surface air temperature estimates shown below (HadCRUT3, NCDC and GISS) the reference period (the normal period) differs. HadCRUT3 refers to the official WMO period 1961-1990, while NCDC and GISS instead uses the periods 1901-2000 and 1951-1980, respectively, which results in higher positive temperature anomalies for these two estimates. For all three surface air temperature estimates shown, small differences in anomalies for past years may occur from time to time due to the addition of recently collected station data or the incorporation of more recent versions of the base data sets.
In the temperature diagrams below, the thick line represents the running 37 month average and the thin line the monthly temperature. Both values are the result of a number of mathematical manipulations with the original temperature data, and especially so the running average. In the text below each diagram you will find a link enabling you to download and analyze the data yourself. All diagrams below are using the same temperature scale, to enable easy visual comparison.
Global monthly average lower troposphere temperature since 1979 according to University of Alabama at Huntsville, USA. This graph uses data obtained by the National Oceanographic and Atmospheric Administration (NOAA) TIROS-N satellite, interpreted by Dr. Roy Spencer and Dr. John Christy, both at Global Hydrology and Climate Center, University of Alabama at Huntsville, USA. This temperature record show good agreement with the independent radiosonde temperature record. The thick line is the simple running 37 month average, nearly corresponding to a running 3 yr average. The cooling and warming periods directly influenced by the 1991 Mt. Pinatubo volcanic eruption and the 1998 El Niņo, respectively, are clearly visible. IPCC = foundation of the International Panel on Climate Change (November 1988). Last month shown: February 2010. Last diagram update: 9 March 2010.
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Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
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Click here to see a maturity diagram for the MSU UAH data series.
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Click here to read about data smoothing.
Global
monthly average lower troposphere temperature since 1979 according to
Remote Sensing Systems (RSS). This graph uses data obtained by the National Oceanographic and
Atmospheric Administration (NOAA) TIROS-N satellite, and interpreted by Dr. Carl Mears
(RSS). The thick line is the simple running 37 month
average, nearly
corresponding to a running 3 yr average. The cooling and warming periods directly influenced by the
1991 Mt. Pinatubo volcanic eruption and the 1998 El Niņo, respectively, are
clearly visible.
Click
here for a description of RSS MSU data products. Please
note that RSS November 2008 changed from Version 3.1 to Version 3.2 of their MSU/AMSU
lower tropospheric (TLT) temperature product, making a number of small changes
and improvements to quality control and merging methods.
Click
here to read an informally description of the
changes made. IPCC
= foundation of the International Panel on Climate Change (November 1988). Last
month shown: February 2010. Last diagram update: 6 March 2010.
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Click here to download the entire series of RSS MSU global monthly lower troposphere temperatures since January 1979.
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Click here to see a maturity diagram for the MSU RSS data series.
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Click here to read about data smoothing.
Global monthly average surface air temperature since 1979 according to Hadley CRUT, a cooperative effort between the Hadley Centre for Climate Prediction and Research and the University of East Anglia's Climatic Research Unit (CRU), UK. The thin line represents the monthly values, while the thick line is the simple running 37 month average, nearly corresponding to a running 3 yr average. The cooling and warming periods directly influenced by the 1991 Mt. Pinatubo volcanic eruption and the 1998 El Niņo, respectively, are visible, but not as clear as in the two satellite records. Click here to read a description of the data file format. An introduction to the dataset has been published by Brohan et al. (2005). Lower down the present page you will find a graph showing the entire series since 1850. IPCC = foundation of the International Panel on Climate Change (November 1988). Base period: 1961-1990. Last month shown: January 2010. Last figure update: 25 February 2010.
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Click here to download the entire series of estimated HadCRUT3 global monthly surface air temperatures since 1850.
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Click here to see a maturity diagram for the HadCRUT3 data series.
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Click here to read about data smoothing.
Global
monthly average surface air temperature since 1979 according to
the National
Climatic Data Center (NCDC), USA. This time series is calculated using land
surface data from the Global
Historical Climatology Network (Version 2) and sea surface temperature
anomalies from the
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Click here to download the entire series of the NCDC global monthly surface air temperatures since 1850.
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Click here to see a maturity diagram for the NCDC data series.
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Click here to read about data smoothing.
Global
monthly average surface air temperature since 1979 according to
the Goddard
Institute for Space Studies (GISS), at
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Click here to download the entire series of the GISS global monthly surface air temperatures since 1880.
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Click here to see a maturity diagram for the GISS data series.
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Click here to read about data smoothing.
The difference between the individual diagrams shown above demonstrate the difficulties associated with calculating a correct average global temperature. Essex et al. (2006) have an interesting discussion of the whole concept of calculating an average global temperature. In addition, global surface air temperatures should only be considered a poor indicator of global climate heat changes, as air has relatively little mass associated with it. Ocean heat changes remain the dominant factor for global heat changes. Global air temperatures, however, continues to attract widespread interest, and many scientist assume that the air temperature at least may be considered a useful proxy for the present state of the global climate system.
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Temporal stability of global air temperature estimates
It is interesting to compare the various global air temperature estimates as to their internal degree of stability for the whole temperature record as such. Especially for surface air temperature estimates, a certain degree of change over time affecting especially the last few months is to be expected, as additional station data may be reported and incorporated in the database. But for the older part of the temperature record numerical stability over time would be expected, provided that the mathematical procedure used for estimating the global temperature is considered mature by the research team preparing the data series considered. In this context, maturity would imply that, for example, the November 1985 temperature reported by a certain database in February 2009 would be identical to the November 1985 value reported previously by the same database.
Below a series of diagrams is shown to illustrate the degree of maturity, calculated for various databases by plotting the net change in their global temperature record since May 2008 (or February 2009). May 2008 (or February 2008) has been chosen as start date for this test as this represents the oldest version of the individual temperature records available to the webmaster. All diagrams below are using the same temperature scale, to enable easy visual comparison.
Please note that new adjustments introduced by the GISS temperature record in February 2010 have made a change of the temperature scale necessary in all maturity diagrams below. At the moment, only the UAH MSS satellite record fulfils the requirement for high temporal stability.
Maturity
diagram showing net change since 8 May 2008 in the global
monthly lower troposphere temperature record prepared by the University
of Alabama at Huntsville, USA. This temperature estimate extends back to
December 1978. Click here to see a graph
showing the most recent version of the UAH MSU global temperature estimate. Click
here to download the entire series of
UAH MSU global monthly lower troposphere temperatures since December 1978. The
UAH MSU temperature record showed a very high degree of temporal stability until
February 2010. In March 2010 a seasonal correction was apparently introduced,
especially affecting the time since 1999. Click
here for explanation of temporal stability. Last
diagram update: 9 March 2010.
Maturity
diagram showing net change since 8 May 2008 in the global
monthly lower troposphere temperature record prepared by the
Remote Sensing Systems (RSS). This temperature estimate extends back to
January 1979. Click here to see a graph
showing the most recent version of the RSS MSU global temperature estimate. Please
note that RSS November 2008 changed from Version 3.1 to Version 3.2 of their MSU/AMSU
lower tropospheric (TLT) temperature product, making a number of small changes
and improvements to quality control and merging methods. This explains most of
the net change since 8 May 2008. Click
here to read an informally description of the
changes made. Click
here to download the entire series of
RSS MSU global monthly lower troposphere temperatures since January 1979. Since
the version change November 2008, the
RSS MSU temperature record shows a very high degree of temporal stability. Click
here for explanation of temporal stability. Last
diagram update: 6 March 2010.
Maturity
diagram showing net change since 25 February 2008 in the global
monthly surface air temperature record prepared by the Hadley
Centre for Climate Prediction and Research and the University
of East Anglia's Climatic Research Unit
(CRU), UK. This
temperature estimate extends back to January 1850. Click
here to see a graph showing the most recent version of the HadCRUT3 global
temperature estimate. Click
here to download the
entire series of HadCRUT3 global monthly
surface air temperatures since January 1850. Previous to January 2010, the HadCRUT3 temperature record
showed a very high degree of temporal stability. The changes shown in the
diagram above are caused by corrections introduced January 2010. Click
here to read about the corrections introduced. Click
here for an explanation of temporal stability. Last diagram update: 25 February 2010.
Maturity
diagram showing net change since 17 May 2008 in the global
monthly surface air temperature record prepared by the National
Climatic Data Center (NCDC), USA. This
temperature estimate extends back to January 1880. Click
here to see a graph showing the most recent version of the NCDC global
temperature estimate. Click
here to download the
entire series of NCDC global monthly surface
air temperatures since January 1880. Click
here for a summary of the recent
(July 2009; Smith
et al. 2008) methodological changes in the land-ocean NCDC temperature analyses. According to
NCDC, this change allows better analysis of temperatures throughout the record,
with the greatest improvements in the late nineteenth century and since 1985.
The present very high temporal instability is at least partly due to this change
of analysis. Click
here for explanation of temporal stability. The net result of the new methodology
is quite substantial, and changes occasionally exceeds 0.1oC. Before
1920 global temperatures are generally changed toward lower values, and toward higher
values after 1920, resulting in a more pronounced 20th century
warming than previously indicated by the NCDC temperature estimate. Last diagram update:
18 February 2010.
Maturity
diagram showing net change since 17 May 2008 in the global
monthly surface air temperature record prepared by the Goddard
Institute for Space Studies (GISS), at
Based on the above it is not possible to conclude which of the above five databases represents the best estimate on global temperature variations. The answer to this question remains elusive. All five databases are the result of much painstaking work, and they all represent admirable attempts towards establishing an estimate of recent global temperature changes. At the same time it should however be noted, that a temperature record which keeps on changing the past hardly can qualify as being correct. With this in mind, it is interesting that none of the global temperature records shown above are characterised by high temporal stability. Presumably this illustrates how difficult it is to calculate a meaningful global average temperature. A re-read of Essex et al. 2006 might be worthwhile. In addition to this, surface air temperature remains a poor indicator of global climate heat changes, as air has relatively little mass associated with it. Ocean heat changes are the dominant factor for global heat changes.
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Comparing global air temperature estimates
In order to enable a visual comparison of the five different global temperature estimates shown above, the diagram below show all series superimposed. As the base period differs for the different temperature estimates (see above), they are not directly comparable. All data series were therefore normalised by setting their starting value in January 1979 = 0, before inclusion in the diagram below. In addition to the visual analysis below, the reader might also find it useful to inspect the maturity analysis presented above.
Superimposed plot of all five global monthly temperature estimates shown above, after setting January 1979 = 0. The two satellite-based temperature estimates (RSS MSU and UAH MSU) at the moment deviate from each other, with RSS MSU being the warmer. The three surface-based temperature estimates (HadCRUT3, GISS and NCDC) also show differences, but smaller. The numbers shown in the lower right represent the anomaly since January 1979 for the last month with data for all five series. See also the diagram below. Values are rounded off to the nearest two decimals, even though some of the the original data series come with more than two decimals. As the base period differs for the different temperature estimates, they have been normalised by setting all starting values in January 1979 = 0. Last month shown: January 2010. Last diagram update: 25 February 2010.
All five global temperature estimates presently show stagnation, at least since 2002. There has been no increase in global air temperature since 1998, which was affected by the oceanographic El Niņo event. This does not exclude the possibility that global temperatures will begin to increase again later. On the other hand, it also remain a possibility that Earth just now is passing a temperature peak, and that global temperatures will begin to decrease within the coming 5-10 years. Only time will show which of these possibilities is the correct. Click here to read a few additional reflections on the recent period of global temperature stagnation.
Diagram showing the average global temperature change (anomaly) since January 1979, according to five global temperature estimates shown above. The upper panel show the average anomalies for the last 12 months, the mid panel show the average anomalies for the last 5 years, while the lower panel show the average anomalies for the last 10 years. As the base period differs for the different temperature estimates, they have all been normalised by setting all starting values in January 1979 = 0. Last month included in analysis: January 2010. Last diagram update: 25 February 2010.
The HadCRUT3 global surface air temperature estimate takes an intermediate position among the five global temperature estimates, but is it impossible to say which of the series shown is the correct one, if any. The intermediate position taken by the HadCRUT3 series, however, is the practical background for displaying this specific temperature estimate below and elsewhere on this website. The HadCRUT3 temperature record also represents the surface air temperature record with the highest degree of temporal stability. Among the satellite-based global temperature estimates the UAH MSU shows the highest degree of agreement with the independent radiosonde record. In addition, the UAH MSU temperature record represents the satellite temperature record with the highest degree of temporal stability.
Usually modern surface air temperatures are compared to the so-called normal temperature, representing the likewise so-called normal climate. This normal temperature is calculated as the average for values recorded during a 30-year period. The period 1961-1990 is the official World Meteorological Organisation (WMO) normal period, and is therefore often referred to. Another 30-year period used as reference for comparisons is 1951-1980. This is partly because the total number of meteorological stations during this period reached a maximum, and since has undergone a marked reduction in number.
Unfortunately, both these periods are dominated by the cold period 1945-1980, and almost any comparison with such a low average value will therefore appear as high or warm. This makes it difficult to decide if surface air temperatures at present are increasing or decreasing? The only thing that will be clear is that modern temperatures are higher than back in this cold period. Click here to see a diagram showing the entire global temperature series (HadCRUT3) since 1850 with the 1945-1980 cold period and the WMO normal period indicated.
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Comparing surface and satellite temperature estimates
Plot showing the average of monthly global surface air temperature estimates (HadCRUT3, GISS and NCDC) and satellite-based temperature estimates (RSS MSU and UAH MSU). The thin lines indicate the monthly value, while the thick lines represent the simple running 37 month average, nearly corresponding to a running 3 yr average. As the base period differs for the various temperature estimates, they have all been normalised by setting starting values in January 1979 = 0. Last month shown: Last month shown: January 2010. Last diagram update: 25 February 2010.
As is shown by the diagram above, the average of surface based temperature estimates is not identical to that obtained by satellites. In general, however, the visual agreement is quite good. The main difference appears to be that of a slightly larger temperature variation recorded by the satellite based estimates. In addition, over the entire period since 1979, the average of the surface based estimates suggests a slightly (<0.1oC) larger global temperature increase, compared to the average of satellite based observations.
Global monthly average surface air temperature (HadCRUT3, NCDC, GISS) minus global monthly average lower troposphere temperature (UAH MSU, RSS MSU) since 1979. The thin blue line shows the monthly temperature difference between anomalies calculated for surface and lower troposphere observations, respectively. The thick blue line is the simple running 37 month average, nearly corresponding to a running 3 yr average. The dotted red line is the linear fit line, statistics of which is presented in the lower right corner of the diagram. As the five data series are using different reference (normal) periods, all data series were normalised by setting January 1979 = 0. Last month shown: January 2010. Last diagram update: 25 February 2010.
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Click here to see the HadCRUT3 temperature diagram since 1979.
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Click here to see the NCDC temperature diagram since 1979.
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Click here to see the GISS temperature diagram since 1979.
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Click here to see the UAH MSU temperature diagram since 1979.
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Click here to see the RSS MSU temperature diagram since 1979.
Global monthly average surface air temperature (HadCRUT3) minus global monthly average lower troposphere temperature (UAH MSU) since 1979. The thin blue line shows the monthly temperature difference between anomalies calculated for surface and lower troposphere observations, respectively. The thick blue line is the simple running 37 month average, nearly corresponding to a running 3 yr average. The dotted red line is the linear fit line, statistics of which is presented in the lower right corner of the diagram. As the two data series are using different reference (normal) periods, both data series were normalised by setting January 1979 = 0. Last month shown: January 2010. Last diagram update: 25 February 2010.
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Click here to see the HadCRUT3 temperature diagram since 1979.
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Click here to download the entire series of estimated HadCRUT3 global monthly surface air temperatures since 1850.
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Click here to see the UAH MSU temperature diagram since 1979.
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Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
According to the HadCRUT3 and UAH MSU temperature records, the surface air temperature have been rising more rapid than the temperature in the lower troposphere since January 1979, about 0.1oC.
The background for chosing the HadCRUT3 and the UAH MSU temperature records to illustrate the developing temperature contrast is based on the above maturity analysis of the temporal stability of individual global temperature estimates. This analysis demonstrated 1) that among the surface air temperature dataseries the HadCRUT3 record represents the record with the highest degree of temporal stability, and 2) that among the satellite-based global tropospheric temperature estimates the UAH MSU record represents the record with the highest degree of temporal stability.
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Diagram showing the latest 5, 10, 20 and 30 yr linear annual global temperature trend, calculated as the slope of the linear regression line through the data points, for two satellite-based temperature estimates (UAH MSU and RSS MSU). Last month included in analysis: January 2010. Last diagram update: 25 February 2010.
Diagram showing the latest 5, 10, 20, 30, 50, 70 and 100 yr linear annual global temperature trend, calculated as the slope of the linear regression line through the data points, for three surface-based temperature estimates (GISS, NCDC and HadCRUT3). Last month included in analysis: January 2010. Last diagram update: 25 February 2010.
The two diagrams above show the calculated linear annual global temperature trend (calculated as the slope of the linear regression line through the data points) for the last 5, 10, 20, 30, 50, 70 or 100 yr period. Trends calculated for 20 years or longer are all clearly positive, typically between 0.01 and 0.02 degrees Celsius per year. Temperature trends calculated for the last 10 years are also positive, but smaller. Trends calculated for the last 5 years are all negative.
Linear trends depend on the length of the time period considered. The shorter the period considered, the more variable the calculated trend will be as new monthly data are added to the data series. In addition, linear trends calculated for short periods often have higher numerical values than trends calculated for longer periods. When comparing linear temperature trends, is is therefore important always to use time periods of similar length. As an visual example of this effect, the diagrams below show trends calculated for the last 100, 30, 20, 10 and 5 years, using the HadCRUT3 data series. In addition, linear trend analyses represent a relatively crude way of numerical analysis, and often a better approximation to the original data may be obtained by using other data models, e.g., polynomial, as shown in the diagrams below. The R2 value may be considered an indicator of the degree of success of the data model adopted. It should also be remembered that several several of the models commonly used for data analysis, including the models shown below, are sensitive to values near the ends points of the data series considered, and especially so for short series.
Last 100 years global monthly average surface air temperature according to Hadley CRUT, a cooperative effort between the Hadley Centre for Climate Prediction and Research and the University of East Anglia's Climatic Research Unit (CRU), UK. The thin blue line represents the monthly values. The thick red line is the linear fit, with 95% confidence intervals indicated by the two thin red lines. The thick green line represents a 5-degree polynomial fit, with 95% confidence intervals indicated by the two thin green lines. A few key statistics is given in the lower part of the diagram. Last month shown: January 2010. Last diagram update: 25 February 2010.
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Click here to download the entire series of estimated HadCRUT3 global monthly surface air temperatures since 1850.
Last 30 years global monthly average surface air temperature according to Hadley CRUT, a cooperative effort between the Hadley Centre for Climate Prediction and Research and the University of East Anglia's Climatic Research Unit (CRU), UK. The thin blue line represents the monthly values. The thick red line is the linear fit, with 95% confidence intervals indicated by the two thin red lines. The thick green line represents a 5-degree polynomial fit, with 95% confidence intervals indicated by the two thin green lines. A few key statistics is given in the lower part of the diagram. Last month shown: January 2010. Last diagram update: 25 February 2010.
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Click here to download the entire series of estimated HadCRUT3 global monthly surface air temperatures since 1850.
Last 10 years global monthly average surface air temperature according to Hadley CRUT, a cooperative effort between the Hadley Centre for Climate Prediction and Research and the University of East Anglia's Climatic Research Unit (CRU), UK. The thin blue line represents the monthly values. The thick red line is the linear fit, with 95% confidence intervals indicated by the two thin red lines. The thick green line represents a 5-degree polynomial fit, with 95% confidence intervals indicated by the two thin green lines. A few key statistics is given in the lower part of the diagram. Last month shown: January 2010. Last diagram update: 25 February 2010.
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Click here to download the entire series of estimated HadCRUT3 global monthly surface air temperatures since 1850.
Last 5 years global monthly average surface air temperature according to Hadley CRUT, a cooperative effort between the Hadley Centre for Climate Prediction and Research and the University of East Anglia's Climatic Research Unit (CRU), UK. The thin blue line represents the monthly values. The thick red line is the linear fit, with 95% confidence intervals indicated by the two thin red lines. The thick green line represents a 5-degree polynomial fit. A few key statistics is given in the lower part of the diagram. Last month shown: January 2010. Last diagram update: 25 February 2010.
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Click here to download the entire series of estimated HadCRUT3 global monthly surface air temperatures since 1850.
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Central England air temperature since 1659
The Central England surface air temperature series is the longest existing meteorological record. The above graphs for annual, summer and winter temperatures have been prepared using the composite monthly meteorological series originally painstakingly homogenized and published by the late professor Gordon Manley (1974). The data series is now updated by the Hadley Centre. Last diagram update: 8 January 2010.
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Click here to download the entire Central England data series since 1659.
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Click here to see a larger version of the above diagram.
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Global monthly average lower troposphere temperature since 1979 for the tropics and the northern and southern extratropics, according to University of Alabama at Huntsville, USA. This graph uses data obtained by the National Oceanographic and Atmospheric Administration (NOAA) TIROS-N satellite, interpreted by Dr. Roy Spencer and Dr. John Christy, both at Global Hydrology and Climate Center, University of Alabama at Huntsville, USA. Thick lines are the simple running 37 month average, nearly corresponding to a running 3 yr average. The cooling and warming periods directly influenced by the 1991 Mt. Pinatubo volcanic eruption and the 1998 El Niņo, respectively, are clearly visible, especially in the tropics and the northern extratropics. Last month shown: February 2010. Last diagram update: 9 March 2010.
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Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
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Click here to read about data smoothing.
Global
monthly average lower troposphere temperature since 1979 for the tropics and the
northern and southern extratropics, according to Remote Sensing Systems
(RSS). These graphs uses data obtained by the National Oceanographic and
Atmospheric Administration (NOAA) TIROS-N satellite, and interpreted by Dr. Carl Mears
(RSS). Thick lines are the simple running 37 month
average, nearly
corresponding to a running 3 yr average. Click
here for a description of RSS MSU data products. Please
note that RSS November 2008 changed from Version 3.1 to Version 3.2 of their MSU/AMSU
lower tropospheric (TLT) temperature product, making a number of small changes
and improvements to quality control and merging methods.
Click
here to read an informally description of the
changes made. Last month shown: February 2010. Last diagram update: 6 March 2010.
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Click here to download the entire series of RSS MSU global monthly lower troposphere temperatures since January 1979.
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Click here to read about data smoothing.
Global monthly average lower troposphere temperature since 1979 for the North Pole and South Pole regions, according to University of Alabama at Huntsville, USA. This graph uses data obtained by the National Oceanographic and Atmospheric Administration (NOAA) TIROS-N satellite, interpreted by Dr. Roy Spencer and Dr. John Christy, both at Global Hydrology and Climate Center, University of Alabama at Huntsville, USA. Thick lines are the simple running 37 month average, nearly corresponding to a running 3 yr average. Last month shown: February 2010. Last diagram update: 9 March 2010.
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Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
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Click here to read about data smoothing.
Global
monthly average lower troposphere temperature since 1979 for the northern polar Pole
(60-82.5N) and southern polar (60-70S) regions, according to
Remote Sensing Systems (RSS). These graphs uses data obtained by the National Oceanographic and
Atmospheric Administration (NOAA) TIROS-N satellite, and interpreted by Dr. Carl Mears
(RSS). Thick lines are the simple running 37 month
average, nearly
corresponding to a running 3 yr average. Click
here for a description of RSS MSU data products. Please
note that RSS November 2008 changed from Version 3.1 to Version 3.2 of their MSU/AMSU
lower tropospheric (TLT) temperature product, making a number of small changes
and improvements to quality control and merging methods.
Click
here to read an informally description of the
changes made. Last month shown: February 2010. Last diagram update: 6 March
2010.
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Click here to download the entire series of RSS MSU global monthly lower troposphere temperatures since January 1979.
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Click here to read about data smoothing.
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Monthly surface air temperature anomalies versus average 1998-2006 in areas between 72oN and 60oN
The
diagram table below contains clickable monthly spatial temperature diagrams since 2005,
to illustrate the changeable geographical pattern of surface air temperature
variations, integrated by graphs like that above. These diagrams are
geographical asymmetrical to cover most of the planets land areas, ranging from
72oN to 60oS.
| YEAR | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANNUAL |
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Spatial distribution of monthly
surface air temperature
deviation between 72oN and 60oS in relation to the average
for the period 1998-2006. Warm colours indicates areas
with higher temperature than the 1998-2006 average, while blue colours indicate lower than average
temperatures.
It
is important to note that the map projection used above is of the type Mercator. This is a useful
cylindrical map projection that preserves angles at all locations, but scale
varies from place to place, distorting the size of land areas. In particular,
areas closer to the poles are more affected, making land areas of similar size
looking increasingly oversized towards the poles. To exemplify this effect, the
areas of
To monitor the present global temperature trend, up or
down, it is not efficient to compare with some past period like, e.g., 1961-1990,
even though this is what is frequently done. This will not inform about
the current temperature trend. It seems to make more sense to compare with a more recent
period.
All the diagrams in the table above were prepared using gridded data downloaded from the public domain NASA Goddard Institute for Space Studies (GISS) web page. For surface interpolation of the gridded data a kriging algorithm was used, plotting all data in a polar projection map. The kriging procedure attempts to express trends and is widely considered one of the more flexible interpolation methods, producing a smooth map with few bull eyes. It is usually recommended for gridding almost any type of data set, especially data sets with a heterogeneous point distribution, such as characterising the present data set. It should be noted that the observation network within the two regions considered is not of equal density or quality all over the geographical regions covered by the diagrams.
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Annual air temperatures global
Anomalies of global annual surface air temperature (MAAT) since 1850 according to Hadley CRUT, a cooperative effort between the Hadley Centre for Climate Prediction and Research and the University of East Anglia's Climatic Research Unit (CRU), UK. The thin line represents the annual values, and the thick line is the simple running 3 year average. The anomaly for 1979 has been set to zero, to make comparison with other temperature data series (below) easy. Last year shown: 2009. Last figure update: 11 March 2010.
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Click here to download the entire series of estimated HadCRUT3 global monthly surface air temperatures since 1850.
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Click here to read about data smoothing.
Anomalies
of global annual surface air temperature (MAAT) since 1880 according to
the National
Climatic Data Center (NCDC), USA. This time series is calculated using land
surface data from the Global
Historical Climatology Network (Version 2) and sea surface temperature
anomalies from the
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Click here to download the entire series of the NCDC global annual surface air temperatures since 1850
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Click here to read about data smoothing.
Anomalies
of global annual surface air temperature (MAAT) since 1880 according to
the Goddard
Institute for Space Studies (GISS), at
-
Click here to download the entire series of the GISS global monthly surface air temperatures since 1880.
-
Click here to read about data smoothing.
Anomalies of global annual surface air temperature (MAAT) since 1979 according to the University of Alabama at Huntsville, USA. This graph uses data obtained by the National Oceanographic and Atmospheric Administration (NOAA) TIROS-N satellite, interpreted by Dr. Roy Spencer and Dr. John Christy, both at Global Hydrology and Climate Center, University of Alabama at Huntsville, USA. The thin line represents the annual values, and the thick line is the simple running 3 year average. The anomaly for 1979 has been set to zero, to make comparison with other temperature data series (above and below) easy. Last year shown: 2009. Last figure update: 19 January 2010.
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Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
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Click here to read about data smoothing.
Anomalies of global annual surface air temperature (MAAT) since 1979 according to the Remote Sensing Systems (RSS). This graph uses data obtained by the National Oceanographic and Atmospheric Administration (NOAA) TIROS-N satellite, and interpreted by Dr. Carl Mears (RSS). The thin line represents the annual values, and the thick line is the simple running 3 year average. Click here for a description of RSS MSU data products. Please note that RSS November 2008 changed from Version 3.1 to Version 3.2 of their MSU/AMSU lower tropospheric (TLT) temperature product, making a number of small changes and improvements to quality control and merging methods. Click here to read an informally description of the changes made. The anomaly for 1979 has been set to zero, to make comparison with other temperature data series (above) easy. Last year shown: 2009. Last figure update: 19 January 2010.
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Click here to download the entire series of RSS MSU global monthly lower troposphere temperatures since January 1979.
-
Click here to read about data smoothing.
Click here to jump back to the list of contents.
Annual air temperature northern hemisphere
Anomalies of Northern Hemisphere annual surface air temperature (MAAT) since 1850 according to Hadley CRUT, a cooperative effort between the Hadley Centre for Climate Prediction and Research and the University of East Anglia's Climatic Research Unit (CRU), UK. The thin line represents the annual values, and the thick line is the simple running 3 year average. The anomaly for 1979 has been set to zero, to make comparison with other temperature data series (below) easy. Last year shown: 2009. Last figure update: 11 March 2010.
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Click here to download the entire series of estimated HadCRUT3 global monthly surface air temperatures since 1850.
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Click here to read about data smoothing.
Anomalies
of Northern Hemisphere annual surface air temperature (MAAT) since 1880 according to
the
National
Climatic Data Center (NCDC), USA. This time series is calculated using land
surface data from the Global
Historical Climatology Network (Version 2) and sea surface temperature
anomalies from the
-
Click here to download the entire series of the NCDC global annual surface air temperatures since 1850
-
Click here to read about data smoothing.
Anomalies
of Northern Hemisphere annual surface air temperature (MAAT) since 1880 according to
the Goddard
Institute for Space Studies (GISS), at
-
Click here to download the entire series of the GISS global monthly surface air temperatures since 1880.
-
Click here to read about data smoothing.
Anomalies of Northern Hemisphere annual surface air temperature (MAAT) since 1979 according to the University of Alabama at Huntsville, USA. This graph uses data obtained by the National Oceanographic and Atmospheric Administration (NOAA) TIROS-N satellite, interpreted by Dr. Roy Spencer and Dr. John Christy, both at Global Hydrology and Climate Center, University of Alabama at Huntsville, USA. The thin line represents the annual values, and the thick line is the simple running 3 year average. The anomaly for 1979 has been set to zero, to make comparison with other temperature data series (above and below) easy. Last year shown: 2009. Last figure update: 24 January 2010.
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Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
-
Click here to read about data smoothing.
Anomalies of Northern Hemisphere annual surface air temperature (MAAT) since 1979 according to the Remote Sensing Systems (RSS). This graph uses data obtained by the National Oceanographic and Atmospheric Administration (NOAA) TIROS-N satellite, and interpreted by Dr. Carl Mears (RSS). The thin line represents the annual values, and the thick line is the simple running 3 year average. Click here for a description of RSS MSU data products. Please note that RSS November 2008 changed from Version 3.1 to Version 3.2 of their MSU/AMSU lower tropospheric (TLT) temperature product, making a number of small changes and improvements to quality control and merging methods. Click here to read an informally description of the changes made. The anomaly for 1979 has been set to zero, to make comparison with other temperature data series (above) easy. Last year shown: 2009. Last figure update: 24 January 2010.
-
Click here to download the entire series of RSS MSU global monthly lower troposphere temperatures since January 1979.
-
Click here to read about data smoothing.
Click here to jump back to the list of contents.
Annual air temperature southern hemisphere
Anomalies of Southern Hemisphere annual surface air temperature (MAAT) since 1850 according to Hadley CRUT, a cooperative effort between the Hadley Centre for Climate Prediction and Research and the University of East Anglia's Climatic Research Unit (CRU), UK. The thin line represents the annual values, and the thick line is the simple running 3 year average. The anomaly for 1979 has been set to zero, to make comparison with other temperature data series (below) easy. Last year shown: 2009. Last figure update: 11 March 2010.
-
Click here to download the entire series of estimated HadCRUT3 global monthly surface air temperatures since 1850.
-
Click here to read about data smoothing.
Anomalies
of Southern Hemisphere annual surface air temperature (MAAT) since 1880 according to
the
National
Climatic Data Center (NCDC), USA. This time series is calculated using land
surface data from the Global
Historical Climatology Network (Version 2) and sea surface temperature
anomalies from the
-
Click here to download the entire series of the NCDC global annual surface air temperatures since 1850
-
Click here to read about data smoothing.
Anomalies
of Southern Hemisphere annual surface air temperature (MAAT) since 1880 according to
the Goddard
Institute for Space Studies (GISS), at
-
Click here to download the entire series of the GISS global monthly surface air temperatures since 1880.
-
Click here to read about data smoothing.
Anomalies of Southern Hemisphere annual surface air temperature (MAAT) since 1979 according to the University of Alabama at Huntsville, USA. This graph uses data obtained by the National Oceanographic and Atmospheric Administration (NOAA) TIROS-N satellite, interpreted by Dr. Roy Spencer and Dr. John Christy, both at Global Hydrology and Climate Center, University of Alabama at Huntsville, USA. The thin line represents the annual values, and the thick line is the simple running 3 year average. The anomaly for 1979 has been set to zero, to make comparison with other temperature data series (above and below) easy. Last year shown: 2009. Last figure update: 24 January 2010.
-
Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
-
Click here to read about data smoothing.
Anomalies of Southern Hemisphere annual surface air temperature (MAAT) since 1979 according to the Remote Sensing Systems (RSS). This graph uses data obtained by the National Oceanographic and Atmospheric Administration (NOAA) TIROS-N satellite, and interpreted by Dr. Carl Mears (RSS). The thin line represents the annual values, and the thick line is the simple running 3 year average. Click here for a description of RSS MSU data products. Please note that RSS November 2008 changed from Version 3.1 to Version 3.2 of their MSU/AMSU lower tropospheric (TLT) temperature product, making a number of small changes and improvements to quality control and merging methods. Click here to read an informally description of the changes made. The anomaly for 1979 has been set to zero, to make comparison with other temperature data series (above) easy. Last year shown: 2009. Last figure update: 24 January 2010.
-
Click here to download the entire series of RSS MSU global monthly lower troposphere temperatures since January 1979.
-
Click here to read about data smoothing.
Click here to jump back to the list of contents.
Temperature change above Equator
Modelled zonally averaged, equilibrated temperature change with altitude associated with doubling atmospheric CO2 (Lee et al. 2007). Units for modelled temperature change are given in degrees Celcius. The horizontal axis begins at 90oN to the left, and ends at 90oS to the right. The vertical axis begins at the planet surface and extends to 10 hPA (ca. 16 km height). For the 200, 300 and 1000 hPa levels (ca. 12, 9 and 0 km altitude, respectively) the observed temperature change since 1979 is shown in the diagrams below.
Lindzen
(1999 and 2007)
argued that the surface temperature anomalies are not the best way of
identifying the effect of an atmospheric CO2 increase. He stressed that the
radiation in the energy flux balance relations can be thought of as coming mainly from the atmospheric layer where the infrared optical depth is near 1.
This characteristic emission layer is high above the surface and is typically
located at an altitude somewhat below the tropopause.
The
height of the tropopause varies with latitude. In the tropics, the tropopause
height is about 16-17 km, near 30° latitude about
12 km, and near the poles the tropopause height is around 8 km above the surface.
The
diagrams above shows how temperature changes when CO2 is doubled in 4
different General Circulation Models (Lee et al.
2007). These model runs differ
from those that were run for the IPCC in that the models were simplified to
isolate the effects of CO2 forcing and climate feedbacks (Lindzen
2007). Also
the models were run until equilibrium was established rather than run in a
transient
mode in order to simulate the past. Thus, they tend to isolate greenhouse
warming from other things that might be going on.
The
model runs shown in the above diagrams
all suggest warming due to CO2 doubling to
peak not at the surface in the tropics, but in the troposphere near the 200-300
hPa level, roughly corresponding to 12-9 km altitude. The
main reason for the inter-model variation is that the amount of water vapour differs among the
models. The expected warming above the tropics is 2-3 times larger than near the surface, regardless of the sensitivity of the
particular model. This is, in fact, the very signature of greenhouse warming (cf.
Lindzen 2007).
In the diagrams below the temperature change at and above Equator is shown, using the Hadley Centre's radiosonde temperature product HadAT (200 and 300 hPa), and HadCRUT3 meteorological surface data. HadAT consists of temperature anomaly time series on 9 standard reporting pressure levels (850hPa to 30hPa), and is derived from 676 individual radiosonde stations with long-term records. Data uncertainties and limitations are described here. The latitudinal band used in the diagrams below is from 20oN to 20oS. To enable easy comparison with the global temperature changes shown higher up this page, 1979 has been chosen as start year. The full HadAT data series, however, goes back to 1958. Please note that the temperature scale in these diagrams are different from the scale used above, to accommodate the larger temperature variations at height. All data series were normalised by setting their starting value in January 1979 = 0, before inclusion in the diagrams below.
Temperature change at 200hPa (c. 12 km height) between 20oN and 20oS since 1979, according to HadAT. The thin blue line shows the monthly values, while the thick blue line represents the simple running 37 month average, nearly corresponding to a running 3 yr average. Click here to read about data smoothing. The stippled red line shows the linear fit for the period shown, with basic statistics shown in the upper left corner of the diagram. The data were normalised by setting January 1979 = 0. Last month shown: September 2009. Last diagram update: 14 December 2009.
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Click here to download the entire HadAT series since 1958.
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Click here to read about data smoothing.
Temperature change at 300hPa (c. 9 km height) between 20oN and 20oS since 1979, according to HadAT. The thin blue line shows the monthly values, while the thick blue line represents the simple running 37 month average, nearly corresponding to a running 3 yr average. Click here to read about data smoothing. The stippled red line shows the linear fit for the period shown, with basic statistics shown in the upper left corner of the diagram. The data were normalised by setting January 1979 = 0. Last month shown: September 2009. Last diagram update: 14 December 2009.
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Click here to download the entire HadAT series since 1958.
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Click here to read about data smoothing.
Temperature change at surface between 20oN and 20oS since 1979, according to HadCRUT3. The thin blue line shows the monthly values, while the thick blue line represents the simple running 37 month average, nearly corresponding to a running 3 yr average. Click here to read about data smoothing. The stippled red line shows the linear fit for the period shown, with basic statistics shown in the upper left corner of the diagram. The data were normalised by setting January 1979 = 0. Last month shown: September 2009. Last diagram update: 14 December 2009.
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Click here to download the entire HadCRUT3 series since 1850.
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Click here to read about data smoothing.
The initial versions of satellite and radiosonde datasets suggested that the tropical surface had warmed more than the troposphere, while climate models consistently showed tropospheric amplification of surface warming in response to human-caused increases in well-mixed greenhouse gases, as shown by the diagrams above. This observation gave rise to deep concern, and resulted in a number of studies (e.g. NRC 2000) where strong attempts were made to find warming in the troposphere. As new data sets have been made available and new corrections introduced, the scientific literature have witnessed a number of attempts of reconciling the modelled and the observed atmospheric warming pattern. Conflicting conclusions have, however, been reached. Some scientists conclude that a discrepancy between modelled and observed trends in tropical lapse rates still exists, while other argue that there is no longer a serious discrepancy. A few key references on this debate are represented by Lindzen 1999 and 2007, NRC 2000, Douglass et al 2007, and Santer et al 2008. Ongoing web-based discussions can be followed here and here. This debate reflects the importance of the point raised by Lindzen (1999) on monitoring temperature changes at the height in the troposphere corresponding to an infrared optical depth near 1.
Diagram showing observed decadal temperature change at surface, 300 hPa and 200 hPa, between 20oN and 20oS, since 1979. Data source: HadAT and HadCRUT3. Click here to compare with modelled temperature change pattern (stippled boxes) with altitude for doubling atmospheric CO2. Last month included in analysis: September 2009. Last diagram update: 15 December 2009.
The three diagrams above (using data from HadAT and HadCRUT3) show the linear trend of the temperature change since 1979 between 20oN and 20oS to be 0.00096oC/month at the surface, 0.00060oC/month at 300 hPa, and -0.00041oC/month at 200 hPa, corresponding to 0.1152, 0.0723 and -0.0487 oC/decade, respectively (see bar chart above).
Thus, these radiosonde and surface meteorological data from the Equatorial region do not at the moment display the signature of enhanced greenhouse warming. With the observed warming rate of about 0.12oC/decade at the surface, a warming rate of at least 0.3oC/decade would have been expected at the 200 and 300 hPa levels to comply with the CO2 hypothesis.
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Outgoing longwave radiation global
Absolute (above) and anomaly (below) weekly outgoing long wave radiation (OLR) at the top of the atmosphere, according to the National Oceanographic and Atmospheric Administration (NOAA) Earth System Research Laboratory (ESRL). Base period January 1979 - December 1995. Latest diagram update: 6 March 2010.
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Click here to see the original ESRL diagram showing OLR absolute values, or to check for a more recent diagram.
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Click here to see the original ESRL diagram showing OLR anomaly values, or to check for a more recent diagram.
Outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 90oN and 90oS since June 1974 according to the National Oceanographic and Atmospheric Administration (NOAA). The thin blue line represents the monthly value, while the thick red line is the simple running 37 month averages, nearly corresponding to the running 3 yr average. Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
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Click here to read about data smoothing.
Scatter plot showing outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 90oN and 90oS since June 1974, as function of atmospheric CO2. OLR data from the National Oceanographic and Atmospheric Administration (NOAA). CO2 data measured at the Mauna Loa Observatory, Hawaii, reported as a dry mole fraction defined as the number of molecules of carbon dioxide divided by the number of molecules of dry air (water vapour removed), multiplied by one million (ppm). The red line represent a two-degree polynomial fit, specified in the lower left corner of the diagram. As the amount of atmospheric CO2 has been increasing over the entire period (ignoring annual variations), the x-axis can be seen as as rough timeline from 1974 (left) to 2010 (right). Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
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Click here to download the entire series of monthly CO2 values since March 1958.
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Click here to read about data smoothing.
Climate models predict that when the amount of atmospheric CO2 increases the natural greenhouse effect will be enhanced, so less less radiation leaves the earth to space, thereby leading to global warming. From this decreasing OLR should be expected as the amount of atmospheric CO2 increases, in contrast to the development since the CO2-concentration passed c. 360 ppm. The diagram above thereby suggests a more complicated association, where the theoretical effect of CO2 on OLR apparently is subordinate to one or several other factors. See also Lindzen and Choi (2009), as well as the diagram below.
Diagram showing outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 90oN and 90oS since December 1978 ( red line; National Oceanographic and Atmospheric Administration (NOAA), and the global monthly average lower troposphere temperature (blue line; University of Alabama at Huntsville, USA). The thin lines represent the monthly values, while the thick lines are the simple running 37 month averages, nearly corresponding to running 3 yr averages. Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
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Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
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Click here to read about data smoothing.
The diagram above suggests an overall association between periods with high global OLR and periods with high global lower tropospheric temperature, and vice versa.
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Outgoing longwave radiation above Equator
Outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 20oN and 20oS since June 1974 according to the National Oceanographic and Atmospheric Administration (NOAA). The thin blue line represents the monthly value, while the thick red line is the simple running 37 month averages, nearly corresponding to the running 3 yr average. Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
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Click here to read about data smoothing.
Scatter plot showing outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 20oN and 20oS since June 1974, as function of atmospheric CO2. OLR data from the National Oceanographic and Atmospheric Administration (NOAA). CO2 data measured at the Mauna Loa Observatory, Hawaii, reported as a dry mole fraction defined as the number of molecules of carbon dioxide divided by the number of molecules of dry air (water vapour removed), multiplied by one million (ppm). The red line represent a two-degree polynomial fit, specified in the lower left corner of the diagram. As the amount of atmospheric CO2 has been increasing over the entire period (ignoring annual variations), the x-axis can be seen as as rough timeline from 1974 (left) to 2010 (right). Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
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Click here to download the entire series of monthly CO2 values since March 1958.
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Click here to read about data smoothing.
Climate models predict that when the amount of atmospheric CO2 increases the natural greenhouse effect will be enhanced, so less less radiation leaves the earth to space, thereby leading to global warming. From this decreasing OLR should be expected as the amount of atmospheric CO2 increases, in contrast to the development since the CO2-concentration passed c. 360 ppm. The diagram above thereby suggests a more complicated association, at least over Equator, where the theoretical effect of CO2 on OLR apparently is subordinate to one or several other factors. See also Lindzen and Choi (2009), as well as the two diagrams below.
Diagram showing outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 20oN and 20oS since December 1978 ( red line; National Oceanographic and Atmospheric Administration (NOAA), and the global monthly average lower troposphere temperature (blue line; University of Alabama at Huntsville, USA). The thin lines represent the monthly values, while the thick lines are the simple running 37 month averages, nearly corresponding to running 3 yr averages. Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
-
Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
-
Click here to read about data smoothing.
Outgoing longwave radiation (OLR; red graph) anomaly at the top of the atmosphere above Equator between 160oE and 160oW since 1979 according to the National Oceanographic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC). Base period: 1979-1995. Surface air temperature change (blue graph) between 20oN and 20oS since 1979, according to HadCRUT3. The thin lines represent the monthly values, while the thick lines is simple running 37 month averages, nearly corresponding to running 3 yr averages. Within the time period 1996-2009, light blue areas indicate periods of surface cooling, and light red areas indicate surface warming. The entire OLR data series goes back to June 1974, but is here shown from January 1979 to enable easy comparison with the temperature diagrams shown above. Last month shown: January 2010 (OLR) and December 2009 (HadCRUT3). Last diagram update: 27 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974.
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Click here to download the entire HadCRUT3 series since 1850.
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Click here to read about data smoothing.
For the equatorial region, the diagram above suggests a certain chain of events, indicating the existence of a mechanism regulating the surface temperature: Periods of surface warming appears initially to be associated with decreasing outgoing longwave radiation (OLR). After some surface warming, OLR then stops decreasing and instead begins to increase, and after a while, surface air temperature then begins to decrease, etc. This chain of events is clearly illustrated by, e.g., the time period around the 1998 El Niņo event (diagram above).
Part of the explanation of the above succession of events might be that tropical surface warming leads to enhanced atmospheric convectional transport of heat to high levels of the atmosphere above the Equator, resulting in enhanced longwave radiation at the top of the atmosphere. This, in turn, eventually leads to surface cooling, which results in reduced atmospheric convection, etc. Also the potential connection to variations in tropical sea surface temperatures and the tropical cloud cover is interesting, and should be considered in a more detailed analysis.
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Outgoing longwave radiation above the Arctic
Outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 70oN and 90oN since June 1974 according to the National Oceanographic and Atmospheric Administration (NOAA). The thin blue line represents the monthly value, while the thick red line is the simple running 37 month averages, nearly corresponding to the running 3 yr average. Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
-
Click here to read about data smoothing.
Scatter plot showing outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 70oN and 90oN since June 1974, as function of atmospheric CO2. OLR data from the National Oceanographic and Atmospheric Administration (NOAA). CO2 data measured at the Mauna Loa Observatory, Hawaii, reported as a dry mole fraction defined as the number of molecules of carbon dioxide divided by the number of molecules of dry air (water vapour removed), multiplied by one million (ppm). The red line represent a two-degree polynomial fit, specified in the lower left corner of the diagram. As the amount of atmospheric CO2 has been increasing over the entire period (ignoring annual variations), the x-axis can be seen as as rough timeline from 1974 (left) to 2010 (right). Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
-
Click here to download the entire series of monthly CO2 values since March 1958.
-
Click here to read about data smoothing.
Climate models predict that when the amount of atmospheric CO2 increases the natural greenhouse effect will be enhanced, so less less radiation leaves the earth to space, thereby leading to global warming. From this decreasing OLR should be expected as the amount of atmospheric CO2 increases, in contrast to the development shown by the diagram above. A different association is thereby suggested, where the theoretical effect of CO2 on OLR apparently is subordinate to one or several other factors. See also Lindzen and Choi (2009), as well as the diagram below.
Diagram showing outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 70oN and 90oN since December 1978 ( red line; National Oceanographic and Atmospheric Administration (NOAA), and the global monthly average lower troposphere temperature (blue line; University of Alabama at Huntsville, USA). The thin lines represent the monthly values, while the thick lines are the simple running 37 month averages, nearly corresponding to running 3 yr averages. Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
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Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
-
Click here to read about data smoothing.
The recorded Arctic OLR has been relatively stable until around 2001, from where a small increase can be observed. A simple explanation on this development would relate the OLR increase to the increasing Arctic lower troposphere temperature since 1994. Perhaps a future Arctic temperature decline is signalled by the UAH MSU record; if this turns out to be correct, it will be interesting to see if OLR will show a similar decline.
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Outgoing longwave radiation above Antarctica
Outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 70oS and 90oS since June 1974 according to the National Oceanographic and Atmospheric Administration (NOAA). The thin blue line represents the monthly value, while the thick red line is the simple running 37 month averages, nearly corresponding to the running 3 yr average. Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
-
Click here to read about data smoothing.
Scatter plot showing outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 70oS and 90oS since June 1974, as function of atmospheric CO2. OLR data from the National Oceanographic and Atmospheric Administration (NOAA). CO2 data measured at the Mauna Loa Observatory, Hawaii, reported as a dry mole fraction defined as the number of molecules of carbon dioxide divided by the number of molecules of dry air (water vapour removed), multiplied by one million (ppm). The red line represent a two-degree polynomial fit, specified in the lower left corner of the diagram. As the amount of atmospheric CO2 has been increasing over the entire period (ignoring annual variations), the x-axis can be seen as as rough timeline from 1974 (left) to 2010 (right). Last month shown: December 2009. Last diagram update: 3 February 2010.
-
Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
-
Click here to download the entire series of monthly CO2 values since March 1958.
-
Click here to read about data smoothing.
Climate models predict that when the amount of atmospheric CO2 increases the natural greenhouse effect will be enhanced, so less less radiation leaves the earth to space, thereby leading to global warming. From this decreasing OLR should be expected as the amount of atmospheric CO2 increases, in concert to what is shown by the diagram above, but in contrast to the global development. See also Lindzen and Choi (2009), as well as the diagram below.
Diagram showing outgoing longwave radiation (OLR) anomaly at the top of the atmosphere between 179oE and 179oW and 70oS and 90oS since December 1978 ( red line; National Oceanographic and Atmospheric Administration (NOAA), and the global monthly average lower troposphere temperature (blue line; University of Alabama at Huntsville, USA). The thin lines represent the monthly values, while the thick lines are the simple running 37 month averages, nearly corresponding to running 3 yr averages. Last month shown: December 2009. Last diagram update: 3 February 2010.
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Click here to download the entire series of NOAA monthly OLR-values since June 1974. Choose first 'OLR' then 'Select field'.
-
Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978.
-
Click here to read about data smoothing.
The recorded Antarctic OLR has been relatively stable throughout the period, however, with a small decline. Antarctic lower tropospheric temperatures has also been almost stable or showing a small decrease, wherefore a simple explanation relating to the diagram above would relate the small OLR decrease to the similar small decrease in Antarctic lower troposphere temperature, similar to what may be observed in the Arctic.
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