A Possible Mechanism for Winter Sea Ice Decline over the Bering Sea and Its Relationship with Cold Events over North America

In this study, the mechanism for the sea ice decline over the Bering Sea and its relationship with cold events over North America are investigated based on the daily ERA-Interim data during the winter (December–February) of 1979–2016. The results show that the sea ice decline over western (eastern) Bering Sea is mainly contributed by (1) the strengthened southerly (southeasterly) wind near the surface, which possibly pushes the sea ice to move northward, and (2) the intensified downward infrared radiation (IR), which is closely related to the local increasing surface air temperature (SAT) and the intensified moisture convergence mostly induced by the anomalous southeasterly wind associated with an anticyclonic anomaly over the Alaska Bay. During the sea ice decline over the Bering Sea, a cold SAT anomaly is simultaneously found over North America. It is proved that the occurrence of such a cold event is driven by the atmospheric internal variation, but not the forcing of sea ice decline over the Bering Sea. This study deepens our understanding of sea ice decline and its relationship with contemporary cold events in winter.