Increased Arctic Sea‐Ice Variability Is Associated With Amplified Air‐Sea Heat Fluxes

Abstract While the role of long‐term sea ice decline in shaping Arctic climate change is well‐established, the contribution of short‐term sea‐ice variability remains insufficiently explored. Here we present observational evidence that since 2007, sea ice fluctuations in Arctic marginal ice zone have remained at a high level. The annual‐mean daily variability of sea ice concentration rose by 11.4%, with high‐variability days becoming more frequent, especially in summer and autumn. Composite analyses reveal enhanced net heat uptake in summer (+11.9%) and greater ocean‐to‐atmosphere heat release in winter (+45.3%), both of which intensify after 2007. Causal analyses reveal a feedback, with higher sea ice variability being closely linked to and reinforced by anomalous net heat fluxes. These findings highlight the increasing short‐term variability of the Arctic sea‐ice and its key role in regulating local air–sea heat exchange.