Abstract Mesoscale SST features influence the atmospheric circulation via strong air–sea interactions. Yet, their contribution to regional climate change remains uncertain. Using a ∼16‐km global atmospheric model forced with mesoscale‐resolving and ‐smoothed SSTs, we assess the impact on the European winter climate under historical (1960–1979) and future (2030–2049) conditions. In the historical period, mesoscale‐resolving SSTs force a spatially heterogeneous atmospheric response that cannot be robustly attributed to Gulf Stream mesoscale SST variability. Contrarily, under future conditions, mesoscale‐resolving SSTs contribute to amplifying European winter changes. Mesoscale SST anomalies intensify latent heat release along the Gulf Stream, strengthening baroclinic instability and North Atlantic storm tracks. This induces a positive NAO‐like pattern that drives warmer and wetter European winters. Removing the mesoscale variability yields the opposite response, with weak storm tracks, enhanced blocking, and muted warming. Mesoscale SST features thus emerge as a key driver of mid‐latitude atmospheric circulation changes under future warming conditions.
Moreno‐Chamarro et al. (Fri,) studied this question.