Summertime atmospheric processes drive recent Arctic Ocean warming

The Arctic Ocean has experienced significant warming in recent decades, particularly in the upper layers. This study investigates the role of summertime atmospheric processes in driving this warming, focusing on the connection between July-August-September (JJA) atmospheric circulation and September-October-November (SON) upper ocean temperatures. Using reanalysis data and a coupled climate model with wind nudging experiments, the authors find a strong link between JJA atmospheric circulation trends and SON upper ocean warming. The wind-driven changes account for a significant portion of the observed warming, especially since 2000, highlighting the importance of internal climate variability in addition to anthropogenic forcing. Poleward ocean heat transport also contributes, particularly through the Atlantic Gate, but its connection to atmospheric processes is less direct. The study emphasizes the need for better model evaluation metrics to capture the complex interactions between atmospheric circulation, sea ice, and ocean warming in the Arctic.

J. Zhang, X. Yuan, W. Wang, T. Zhang, X. Li, S. Li, C. Liu, J. Liu, J. Gong, X. Wu