Summer Temperature Variations in the Arctic during Interglacials

Abstract

Modelling the effects of orbital variations on temperatures in the Canadian Arctic during interglacials like the present is relevant to the question of the time of onset of the next glaciation. Summer temperature profiles were calculated for Yellowknife (62.5°N-114°W) for the intervals from 125 000 years BP to 115 000 years BP and 6 000 years BP to 8 000 years AP. The model used numerically-integrated absorbed insolation values at 65°N, 45°N and 25°N. Albedos were calculated as a function of solar zenith angle with parameters consistent with satellite observations. At Yellowknife, not far from the Keewatin glacial nucleation area, model temperatures for July fall 4°C below present at 117 000 years BP near the Wisconsin/Weichselian glacial onset, and rise from a minimum near present to about 1.5°C above present at 8 000 years AP. This temperature rise suggests a continuation of the present major interglacial to at least 8 000 years AP.