Observed climate variations during the last 100 years in Lapland, northernFinland

Many general circulation models (GCMs) predict that high latitude environme nts will experience substantial warming over the next 100 years, which will be particularly pronounced during the winter months. Precipitation is also expected to increase but there is uncertainty as to the amount and spatial variation. The flora and fauna of the arctic and subarctic regions, together with indi genous people, such as the Saami, are particularly vunerable to rising temp eratures and changing precipitation. Mean monthly temperature and precipita tion data were examined for the last 100 years for northern Finland. These data were further analysed for the first and second half of the 20th centur y. There was no discernible warming trend between 1876 and 1993, but a signifi cant annual warming (r=0.344, rho < 0.05) occurred in the period 1901-1945, together with a significant summer warming (r = 0.381, rho < 0.05). Warmin g has occurred consistently in May and June over the last 100 years and the re appears to be a current (i.e. post 1990) annual trend, mostly due to win ter warming. The greatest temperature anomaly increase for the period 1901- 1945 was in the winter months (+ 0.72 degrees C). The degree of temperature variation in the winter is greater than in the summer and has risen from 3 .98 degrees C for December in the period 1901-1945 to 4.37 degrees C in the period 1946-1990. This is attributed to the recent high variability in the North Atlantic Oscillation (NAO) Index. Annual precipitation has increased significantly during the period 1880-199 3. The period 1946-1990 was wetter than 1901-1945, with greater variability particularly in the summer months, which contribute most to the annual pre cipitation in Lapland. Copyright (C) 2000 Royal Meteorological Society.