A quantitative Holocene climatic record from diatoms in northern Fennoscandia

A diatom-based calibration model for predicting summer temperatures was dev eloped using climatically sensitive subarctic lakes in northern Fennoscandi a. The model was applied to a sediment core from a treeline lake to infer t rends in Holocene climate. The record exhibits long-term variations, as wel l as a series of shorter-term fluctuations on a time scale of centuries. Su mmers were warmest in the area about 6200 cal yr B.P. and featured distinct cooling episodes around 8300, 7200, 4200, 3000, and 400 cal yr B.P., most of these coinciding with some known climate events (e.g., the 8200 cal yr B .P. event and the Little Ice Age). The similarity of the observed shifts wi th the pacings of climate events from marine and ice-core records represent s evidence for coupled ocean-atmosphere forcing of the regional climate. (C ) 2000 University of Washington.