Linking glacier extent and summer temperature in NE Russia - Implications for precipitation during the global Last Glacial Maximum

Abstract

It is generally assumed that during the global Last Glacial Maximum (gLGM, i.e. 18–24 ka BP) dry climatic conditions in NE Russia inhibited the growth of large ice caps and restricted glaciers to mountain ranges. However, recent evidence has been found to suggest that glacial summers in NE Russia were as warm as at present while glaciers were more extensive than today. As a result, we hypothesize that precipitation must have been relatively high in order to compensate for the high summer temperatures and the resulting glacial ablation. We estimate precipitation abundance by mass balance calculations for the palaeo-glaciers on Kamchatka and in the Kankaren Range using a degree-day-modelling (DDM) approach, and find that precipitation during the gLGM was likely comparable to, or even exceeded, the modern average. We suggest that stronger than present southerly winds over the Northwest Pacific may have accounted for the abundant precipitation. The DDM-results imply that summer temperature, rather than aridity, limited glacier extent in the southern Pacific Sector of NE Russia during the gLGM