Northern Hemisphere atmospheric blocking in ice core accumulation records from northern Greenland

Abstract

We investigate the connection between frequency of atmospheric blocking circulation and the variability of five high-resolution accumulation records from northern Greenland. It is shown that during years of high ice accumulation records the frequency of winter blocking circulation in the Euro-Atlantic region is significantly higher relative to the years of low accumulation. Our results show an enhanced Greenland storm track as well as enhanced moisture transport toward Greenland during the periods of high blocking activity relative to the periods of low blocking activity. The time series associated with the dominant mode of accumulation variability shows significant multidecadal variations during the last five centuries. We suggest that the positive (negative) phase of these multidecadal oscillations is related to high (low) blocking activity in the Euro-Atlantic region. Copyright 2007 by the American Geophysical Union.