[ Updated 6 June 2018 ]
Long-term air temperature records at 13 stations (all polar research bases) in Antarctica have been extracted from the website of KNMI (Royal Dutch Meteorological Institute). The KNMI database has records up to April or May 2018.
These are all raw data, without any adjustments ever having been made (as far as I am aware). Only stations with records over a period of at least 50 years, with largely complete and post-2010 records were selected. Eleven of the stations are located in coastal areas of the continent and of these three are located on the more northerly Antarctic Peninsula (south of South America). Two stations are located at higher, inland locations including one station at the South Pole.
I have not been able to make any quality checks on the data. It is possible that there have been some changes in station locations and instrumentation over the periods of record, but sudden steps in the data and comparisons with other adjoining stations would be expected to identify any inconsistencies.
Graphical plots are presented below of annual mean temperatures at each of the 13 stations. [ Annual mean temperatures are the average of the mean daily temperatures over each year (the mean daily temperatures are the average of the observed daily maximum and minimum temperatures). ] A polynomial trend line was fitted through each of the sets of data.
Similar analyses were made of the 12 mean monthly temperatures at each location. These showed that there are seasonal variations in the temperature trends. Also, the sample size was greater than for the annual analyses (when data were only used if complete years of data were available). These monthly analyses will be presented in later posts.
A more detailed analysis of the temperature trends at Mawson may be seen at: http://members.westnet.com.au/brigun/mawson-temps.html
Halley (UK), Antarctica 51 complete years of data, 1956-2018
Novolazarevsk (Russia), Antarctica 33 complete years, 1961-2018
Syowa (Japan), Antarctica 47 complete years of data, 1957-2018
Mawson (Australia), Antarctica 58 complete years of data, 1952-2018
Davis (Australia), Antarctica 50 complete years of data, 1957-2018
Mirnyj (Russia), Antarctica 44 complete years of data, 1956-2018
Casey (Australia), Antarctica 55 complete years of data, 1957-2018
Dumont d’Urville (France), Antarctica 48 complete years of data, 1950-2018
Vostok (Russia), Antarctica 34 complete years of data, 1958-2018
Amundsen-Scott (USA), Antarctica 45 complete years of data, 1954-2018
Rothera (UK), Antarctica 47 complete years of data, 1946-2018
Faraday/Vernadsky (UK/Ukraine), Antarctica 55 complete years of data, 1944-2018
Esperanza (Argentina), Antarctica 51 complete years of data, 1945-2018
Apart from at the three stations located on the Antarctic Peninsula, none of the records at the other ten stations show any consistent trend to either increase or decrease significantly over the past 50 years.
The three stations located on the Antarctic Peninsula all have increasing temperatures over the past 60-70 years, although there are differences in magnitude. The mean annual increase varies from about 1.5ºC/century (at Esperanza) to about 3ºC/century at Rothera. It is possible that these three stations are affected by changing wind patterns, ocean currents or volcanic activity that don’t affect the more southerly stations.
The effectively zero temperature trends for the main regions of the Antarctic continent are interesting and possibly significant. In most regions of the world there have been a well-defined, but not alarming, increase (of less than 1ºC/century) in mean annual temperature over the past 100-150 years but, for the main land mass of Antarctica, such a trend cannot be identified in the records of the past 60-70 years.
This post was written by Brian Gunter of Narooma, NSW. In his previous life Brian was an engineering hydrologist involved over many years in the analysis of rainfall and river flow data for the planning of water resources projects in Australia, Asia and Africa. In recent years he has been one of the Marine Rescue NSW (previously Royal Volunteer Coastal Patrol) volunteer weather observers who operate the Narooma station for the Bureau of Meteorology.