Abstract
Air temperature data from weather stations on Svalbard (including temporary stations with periods of record of less than one year) reveal that on the archipelago, and indeed in the western sector of the Arctic in general, mean annual temperatures over the period 1872–1912 were 3–4° lower than those in the period 1950–1979, and mean summer temperatures 0.5–0.7° lower. A significant and rapid climatic warming occurred in the third decade of this century. This is reflected in two cores obtained from the Austfonna, Nordaustlandet in 1985 and 1987. In both cores the concentration of infiltration ice approximately doubled. The sections show graphically that no warmings with amplitude and duration comparable to that of present have been observed on Svalbard for about a millennium. The abrupt increase in the content of infiltration ice in the cores, resulting from the very rapid climatic warming in the 1920s, allows one to date the cores and also to determine the mean accumulation for the period 1920–1987.