Responses of climate and cyclones to reductions in Arctic winter sea ice

Abstract

A perpetual January simulation of the global atmosphere has been used to study the climatology of the northern hemisphere winter. Lows were tracked using an objective scheme and were analyzed for a number measures of cyclone behavior. The qualitative features of the cyclone density and flux distributions compare well with observations, except in certain respects noted. Descreases in sea ice concentration produced a monotonic but nonlinear warming in the lower troposphere and weakening and southward contraction of the midlatitude westerlies. Mean sea level pressure reductions were biased toward the western Arctic. There was a significant decrease in the speeds and intensities of cyclonic syst..