Diagnosing ocean eddy heat and salt fluxes from satellite altimetry and Argo profile data
Event: 2017 Ocean Surface Topography Science Team Meeting
Session: Science III: Mesoscale and sub-mesoscale oceanography
Presentation type: Type Poster
Contribution: PDF file
Mesoscale eddies are believed to play an important role in the ocean transport of heat and salt. Yet, eddy transports are difficult to observe, mainly because of the difficulties in gathering observations with sufficient time and space resolution to resolve the eddy field. In this study, transport properties of mesoscale eddies in various parts of the world ocean are diagnosed from a synergistic use of satellite altimetry data and in-situ temperature and salinity profiles collected by Argo floats. The eddy transports related to coherent mesoscale eddies are expectedly strong in the western boundary currents and in the Southern Ocean along the Antarctic Circumpolar Current (ACC). The transports are generally weak, but not negligible in gyre interiors. In the vertical, the eddy heat and salt transports are surface-intensified and confined mainly to the upper ~500 m layer, but their distribution with depth is not homogeneous throughout the ocean. In the Kuroshio extension (KE) region, for example, the eddy heat transport is poleward everywhere in the surface layer above the thermocline, but oppositely signed relative to the jet’s axis in a deeper layer between approximately 300-800 m, where the transport is poleward on the northern side of the jet and equatorward on its southern side. Relatively strong eddy transports at depth are also observed in the ACC, particularly in the Indian sector, and in the subtropical North Atlantic at the level of the Mediterranean Water (MW) at around 1000 m depth. The latter exemplifies the role of eddies in MW spreading. These and other features of the longitude-latitude-depth distributions of the eddy heat and salt transports, constructed exclusively from observational data, are presented and discussed.