The atmospheric frontal response to SST perturbations in the Gulf Stream region

Abstract

Abstract The link between sea surface temperature (SST) gradients and atmospheric fronts is explored in a general circulation model across the Gulf Stream (GS) region from December to February 1981–2000. Two model experiments are analyzed, one with a realistic control SST distribution and one with a spatially smoothed SST distribution. The analysis shows a noticeable change in regional atmospheric frontal frequency between the two experiments (up to 30%), with the distribution of change exhibiting a clear imprint of the GS SST front. Further analysis of the surface sensible heat flux gradient across cold fronts reveals the pattern of change to be mediated by a thermal interaction between the oceanic and atmospheric fronts (“thermal damping and strengthening”). These results not only emphasize the significance of the GS SST gradient for storm development in the North Atlantic but also highlight the importance of resolution in assessing the role of frontal air‐sea interaction in midlatitude climate variability.