Possible Effects of Tropical Cyclone Activities over Eastern North Pacific on Arctic Sea Ice

The rapid loss of Arctic sea ice has sparked considerable interest in understanding the factors that influence its variability. This study investigates the teleconnection between tropical cyclone (TC) activities in the eastern North Pacific (ENP) and sea ice concentration (SIC) over the Arctic. Observational analysis reveals that ENP TC activities during summer contribute to decelerating the loss of the Arctic sea ice in September. Mechanistically, ENP TC activities induce large-scale meridional circulation anomalies that modify Arctic atmospheric circulation, resulting in anomalous northwesterly winds over the Arctic. This leads to decreased surface temperatures and humidity, thereby facilitating sea ice growth. Simulations confirm that TC-driven atmospheric changes contribute to an increase in SIC. The significance of tropical-extratropical teleconnections in Arctic climate variability is emphasized by these findings, suggesting that ENP TC activities could serve as a novel tropical factor for predicting SIC over the Arctic.