The role of cyclone activity in the interannual variability of the summertime Beaufort High

Abstract

The Beaufort High (BH) is a well-known climatological feature of the Arctic with close ties to sea ice variability. Here, an objective cyclone-tracking algorithm was utilized to link the summertime interannual variability of the BH to cyclone migration pattern and its intensity. The results indicated that rather than the in situ change of anticyclone in the region, the variability of BH is influenced more by passive effects of cyclone activity with its center near the North Pole. The effect of cyclones is twofold. One is the effect of more intense cyclones entering the peripheral region of the BH where three times as many cyclones below 980 hPa reach the Arctic for years in which BH is weak. The other is intensification of cyclones forming within the Arctic contributing to an average difference of 4.9 hPa between years with strong and weak BH. We argue that along with the in-situ change in the BH, such peripheral cyclone activity spreads into the BH region strongly affecting the observed interannual variability.