The Role of Barents Sea Ice in the Wintertime Cyclone Track and Emergence of a Warm-Arctic Cold-Siberian Anomaly

Sea ice variability over the Barents Sea with its resultant atmospheric response has been considered one of the triggers of unexpected downstream climate change. For example, East Asia has experienced several major cold events while the underlying temperature over the Arctic has risen steadily. To understand the influence of sea ice in the Barents Sea on atmospheric circulation during winter from a synoptic perspective, this study evaluated the downstream response in cyclone activities with respect to the underlying sea ice variability. The composite analysis, including all cyclone events over the Nordic seas, revealed that an anticyclonic anomaly prevailed along the Siberian coast during light ice years over the Barents Sea. This likely caused anomalous warm advection over the Barents Sea and cold advection over eastern Siberia. The difference in cyclone paths between heavy and light ice years was expressed as a warm-Arctic cold-Siberian (WACS) anomaly. The lower baroclinicity over the Barents Sea during the light ice years, which resulted from a weak gradient in sea surface temperature, prevented cyclones from traveling eastward. This could lead to fewer cyclones and hence to an anticyclonic anomaly over the Siberian coast.