Temperature Trends in Antarctica

In general, a temperature increase has been observed in Antarctica. While most of the stations in Antarctica operate since the IGY (1958), this trend goes much further back, as can be seen from the station ORCADAS, located close to Antarctica on the South Orkney Island. Its record goes back to early in this century (1904). This station shows a temperature increase of about 2°C per century. This rate of increase is in general agreement with other coastal stations; the Antarctic Peninsula shows even a higher rate of increase.

There are a fairly large number of coastal stations, which have been operated by Argentinea, Australia, Britain, Chile, France, New Zealand, Russia and USA for the last 40 years. All these coastal stations show an increase in temperature, the magnitude of which varies. However, there are only two long term interior stations, namely Vostok (Russia) and Amundsen-Scott Pole Station (USA). While Vostok shows an increase similar to the one observed for the coastal stations, Pole Station recorded a decrease in temperature. It is possible to explain an opposite trend in temperature for coastal and high plateau stations, as due to increased advection of warm air from the north which caused the observed warming at the coastal stations, the temperature gradient with height will have been affected. However, it is difficult to explain the opposite trend for the two plateau stations, as both are located at similar altitudes and far from the coast. Furthermore, the uniform surface of snow (melting never occurs) make it difficult to explain it owing to local topographic effects.

We analyzed the data of these stations together with other shorter term stations in the Interior of Antarctica, including AWS (Automatic Weather Stations), and discuss the significance and reliability of these two opposing trends.