资源环境科技发展态势分析平台

Storm tracks are a pivotal component in extratropical weather and climate. The sea surface temperature (SST) front in the midlatitude South Indian Ocean has been found to anchor the climatological core of the Southern Hemisphere (SH) storm tracks. However, on interannual‐to‐decadal time scales, observational and modelling evidence is presented here that the strengthened SST front in the midlatitude western South Atlantic (SA) can intensify the SH summer storm tracks by supplying more baroclinic energy, which overwhelms contributions from other oceanic frontal zones. Idealized experiments suggest that such a predominant impact on synoptic storms lies in the strengthened SA SST front acting in concert with the favorable thermal background produced in the presence of the Andes (i.e., enhancements of downstream low‐level temperature gradients and synoptic temperature variability). Our findings imply that oceanic variability in the western SA frontal zone could be a remote regulator of the SH extratropical summer climate variability.