The effects of different sudden stratospheric warming type on the ocean: Ocean impacts of SSWs

There is a confirmed link between sudden stratospheric warmings (SSWs) and surface weather. Here we find significant differences in the strength of surface and ocean responses for splitting and displacement SSWs, classified using a new straightforward moment analysis technique. In an intermediate general circulation model splitting SSWs possess an enhanced ability to affect the surface climate demonstrating the need to treat the two types individually. Following SSWs the North Atlantic surface wind stress curl weakens, compared to its climatological winter state, for over 30 days: this is also evident in NCEP/NCAR reanalysis. The effect of anomalies associated with SSWs on the ocean is analysed in the Intermediate General Circulation Model 4. The splitting SSW composite displays strong anomalies in the implied Ekman heat flux and net atmosphere-surface flux, modifying the mixed layer heat budget. Our results highlight that different SSW types need to be simulated in coupled stratospheric/tropospheric/ocean models.