资源环境科技发展态势分析平台

This observational study uses high-resolution data to investigate mesoscale signatures of the North Atlantic Oscillation (NAO) in the atmosphere and ocean. The production of spatially high-pass ("mesoscale") filtered kinetic energy by buoyancy and shear effects in the atmosphere, along with sea surface temperature and surface currents in the ocean is described, and a difference with NAO phase is found. In positive NAO winters, an extension of the Gulf Stream warm core is observed, along with a displacement and acceleration of surface currents. Mesoscale activity in the atmosphere appears to follow this extension of the warm core of the Gulf Stream. This, we suggest, is a new feature of NAO air-sea interactions which is embedded within the basin-scale NAO patterns discussed previously in the literature. Further downstream, mesoscale activity seems to reflect more passively the general poleward migration of synoptic activity in positive NAO conditions.