Polar temperatures

General

The two polar regions are usually identified as key regions for monitoring global climate change, because the surface air temperature is expected to increase especially rapid in these two regions along with the ongoing increase of atmospheric CO₂. Below we therefore focus on past and climate change in both polar regions during the period with meteorological observations; first of all illustrated by observed changes in mean annual surface air temperature for regions north of 70^oN and south of 70^oS, respectively.

Mean annual surface air temperature (MAAT) anomaly 70-90^oN compared to the WMO normal period 1961-1990, as estimated by Hadley CRUT. HadCRUT3 temperature data from the Climatic Research Unit (CRU) has been used to prepare the diagram. A description of these data can be seen by clicking here. The HadCRUT3 data can be downloaded from the same website. The temperature record shows that the Little Ice Age apparently ended around 1920 in regions north of 70^oN with a marked temperature increase, much more rapid than any other temperature on record. Temperatures then reached a maximum around the start of the 2nd World War, followed by a new temperature decrease. The WMO normal period 1961-1990 represents the period of maximum cold north of 70^oN after the 2nd World War. Since around 1990 surface air temperatures have again increased, although modern temperatures still are slightly below the level characterising the period shortly before 1940. The number of available meteorological stations in the early part of the 20^th century is low, and this best estimate therefore associated with relatively large uncertainty for this part of the total period.

Mean annual surface air temperature (MAAT) anomaly 70-90^oS compared to the WMO normal period 1961-1990, as estimated by Hadley CRUT. The international geophysical year 1957 marks the initiation of widespread meteorological observations in the Antarctic.  HadCRUT3 temperature data from the Climatic Research Unit (CRU) has been used to prepare the diagram. A description of these data can be seen by clicking here. The HadCRUT3 data can be downloaded from the same website. In essence, surface air temperatures south of 70^oS has been stable during the instrumental period since 1957.

Global monthly average lower troposphere temperature since 1979 for the North Pole and South Pole regions, based on satellite observations (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. Click here to read about data smoothing. Click here to download the entire series of UAH MSU global monthly lower troposphere temperatures since December 1978. 

• 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.

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:

Monthly surface air temperature anomalies versus the average 1998-2006 in areas north of 50^oN, including the Arctic

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Spatial distribution of monthly surface air temperature deviation north of 50^oN 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. By adopting this recent reference period, instead of the official WMO period 1961-1990, is will gradually be possible to visualize if 1998-2006 represents a peak period for the global average temperature, or if modern temperatures are increasing to a even higher level. In the individual diagrams the month is indicated by a number: 1 = January, 2 = February, etc. Click on the individual small diagrams to open full-size diagrams. Please also read the notes here before interpreting the diagrams. Similar spatial temperature diagrams showing the equatorial regions can be seen by clicking here. Data source: NASA Goddard Institute for Space Studies (GISS). Last diagram update 18 February 2010.  

Diagram showing Arctic monthly surface air temperature anomaly 70-90^oN since January 2000, in relation to the WMO normal period 1961-1990. The thin blue line shows the monthly temperature anomaly, while the thicker red line shows the running 13 month average. Since January 2000, the average monthly air temperature is 1.31^oC above the cold 1961-1990 average. In general, the Arctic temperature record appears to be less variable than the contemporary Antarctic record, presumably at least partly due to the higher number of meteorological stations north of 70^oN, compared to the number of stations south of 70^oS. A diagram showing Arctic temperature variations north of 70^oN since 1900 can be seen here. Data source: HadCRUT3 temperature data from the Climatic Research Unit (CRU). 

Diagram showing Arctic monthly surface air temperature anomaly 70-90^oN since January 1957, in relation to the WMO normal period 1961-1990. The year 1957 has been chosen as starting year, to ensure easy comparison with the maximum realistic Antarctic temperature record. The thin blue line shows the monthly temperature anomaly, while the thicker red line shows the running 13 month average. In general, the Arctic temperature record appears to be less variable than the contemporary Antarctic record, presumably at least partly due to the higher number of meteorological stations north of 70^oN, compared to the number of stations south of 70^oS. A diagram showing Arctic temperature variations north of 70^oN since 1900 can be seen here. Data source: HadCRUT3 temperature data from the Climatic Research Unit (CRU). 

Diagram showing Arctic monthly surface air temperature anomaly 70-90^oN since January 1900, in relation to the WMO normal period 1961-1990. The thin blue line shows the monthly temperature anomaly, while the thicker red line shows the running 13 month average. In general, the range of monthly temperature variations decreases throughout the first 30-50 years of the record, reflecting the increasing number of meteorological stations north of 70^oN over time. Especially the period from about 1930 saw the establishment of many new Arctic meteorological stations, first in Russia and Siberia, and following the 2nd World War, also in North America. Because of the relatively small number of stations before 1930, details in the early part of the Arctic temperature record should not be over interpreted. The rapid Arctic warming around 1920 is, however, clearly visible, and is also documented by other sources of information. The period since 2000 is warm, about as warm as the period 1930-1940. Diagrams showing more recent variations of Arctic temperatures north of 70^oN in greater detail are shown here, here and here. Data source: HadCRUT3 temperature data from the Climatic Research Unit (CRU). 

Note to the three Arctic temperature diagrams above: As data coverage is sparse in the polar regions, the procedure of Gillet et al. 2008 has been followed, giving equal weight to data in each 5^ox5^o grid cell when calculating means, with no weighting by the areas of the grid dells. 

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Long Arctic meteorological data series

Long Arctic surface annual air temperature series: Fairbanks (Alaska), Nuuk (Greenland), Akureyri (Iceland), Svalbard (Norway), Ostrov Dikson (Siberia), and Hatanga (Siberia). Annual values were calculated from monthly average temperatures. Almost unavoidably, some missing monthly data were encountered in some of the series. In such cases, the missing values were generated as either 1) the average of the preceding and following monthly values, or 2) the average for the month registered the preceding year and the following year. The thin blue line represents the mean annual air temperature, and the thick blue line is the running 5 year average. Click here to read about data smoothing. Data source: NASA Goddard Institute for Space Studies (GISS).

For the Arctic, a major focus has been the Arctic Climate Impact Assessment. Based on the results from an average of the output from five climate models, which were also used for the IPCC, temperature projections were produced for the next century. The models all predicted a steady rise in annual mean surface air temperature with, on average, temperatures being 4^oC higher by 2100, corresponding to an average decadal temperature increase of 0.4^oC (World Meteorological Organization 2007).

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Monthly surface air temperature anomalies versus the average 1998-2006 in areas south of 50^oS, including the Antarctic

YEAR

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

ANNUAL

2010

2009

2008

2007

2006

2005

Spatial distribution of monthly surface air temperature deviation south of 60^oS 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. By adopting this recent reference period, instead of the official WMO period 1961-1990, is will gradually be possible to visualize if 1998-2006 represents a peak period for the global average temperature, or if modern temperatures are increasing to a even higher level. In the individual diagrams the month is indicated by a number: 1 = January, 2 = February, etc. Click on the individual small diagrams to open full-size diagrams. Similar spatial temperature diagrams showing the equatorial regions can be seen by clicking here. Please also read the notes here before interpreting the diagrams. Data source: NASA Goddard Institute for Space Studies (GISS). Last diagram update 18 February 2010.

Diagram showing Antarctic monthly surface air temperature anomaly 70-90^oS since January 2000, in relation to the WMO normal period 1961-1990. The thin blue line shows the monthly temperature anomaly, while the thicker red line shows the running 13 month average. Since January 2000, the average monthly air temperature is -0.02^oC below the 1961-1990 average. In general, the Antarctic temperature record appears to be more variable than the contemporary Arctic record, presumably at least partly due to the smaller number of meteorological stations south of 70^oS, compared to the number of stations north of 70^oN. Data source: HadCRUT3 temperature data from the Climatic Research Unit (CRU). 

Diagram showing Antarctic monthly surface air temperature anomaly 70-90^oS since January 1957, in relation to the WMO normal period 1961-1990. The year 1957 was an international geophysical year, and several meteorological stations were established in the Antarctic because of this. Before 1957, the meteorological coverage of the Antarctic continent is poor. The thin blue line shows the monthly temperature anomaly, while the thicker red line shows the running 13 month average. In general, the Antarctic temperature record appears to be more variable than the contemporary Arctic record, presumably at least partly due to the smaller number of meteorological stations south of 70^oS, compared to the number of stations north of 70^oN. Data source: HadCRUT3 temperature data from the Climatic Research Unit (CRU). 

Note to the two Antarctic temperature diagrams above: As data coverage is sparse in the polar regions, the procedure of Gillet et al. 2008 has been followed, giving equal weight to data in each 5^ox5^o grid cell when calculating means, with no weighting by the areas of the grid dells.