Tropical Indian Ocean warming drives an increase in bering sea ice concentration

Arctic sea ice has undergone rapid changes in recent decades and exhibited significant interannual variability. Factors such as changes in greenhouse gas concentrations, sea ice-albedo feedback, and cloud feedback are known to influence Arctic sea ice variability. Both the Pacific and the Atlantic oceans have been reported to impact Arctic sea ice through atmospheric and oceanic processes. However, limited research has focused on the influence of the Indian Ocean on Arctic sea ice, partly due to the considerable distance between the Indian and Arctic Ocean basins. This study investigates the influence of tropical Indian Ocean warming on the Arctic sea ice concentration (SIC). Through statistical analysis and numerical experiments, we demonstrate that tropical Indian Ocean warming can increase Bering Sea SIC in boreal winter (December-January-February, DJF). The warming excites a Rossby wave train that propagates into the high-latitude Pacific Ocean, resulting in an anomalous low-pressure center over the Bering Strait. The associated cyclonic circulation induces a pronounced southwestward drift of sea ice from the Bering Sea to the high-latitude North Pacific, extending from the Bering Strait to about 60 degrees N over the North Pacific, contributing to the increase in Bering Sea SIC. This result establishes a robust linkage between the Indian Ocean and the Arctic, which may largely influence the predictability and the future projection of Arctic climate. Moreover, given that Arctic sea ice may provide feedback to the Indian monsoon system, these two areas thus form an interactive system that requires further investigation.