Have Impacts of Intense Arctic Cyclones on Summer Sea Ice Reached a Maximum?

Abstract

Observations show that Arctic cyclones can significantly affect the marginal ice zone (MIZ). Understanding how these effects may evolve in the future is critical for accurately predicting future ice loss, yet cyclone-sea ice interactions in global climate models are understudied. This analysis compares output from the Community Earth System Model version 2 Large Ensemble (CESM2-LE) with observed intense summer cyclone impacts on the MIZ. We find that CESM2-LE reproduces observed net impacts but exhibits compensating biases, where fewer intense cyclones reach the MIZ but decrease ice area more than observed. In a future emission scenario, CESM2-LE predicts more frequent intense cyclones, but as the Arctic warms and late summer ice cover lessens, fewer storms will interact with the retreating ice edge. Subsequently, the largest effects shift earlier in the year, and ice loss from these storms declines after present day, suggesting intense summer cyclone impacts have reached a maximum.