Surface forcing of ocean heat content in Drake Passage

Air-sea fluxes modify dense water outcropping in the Southern Ocean, influencing long-term storage of heat in the interior ocean. Understanding the oceanic response to surface heating is crucial to anticipating the response of this sensitive region to anthropogenic changes in surface fluxes. Long-term monitoring by repeat XBT/XCTD transects across Drake Passage are used in this study to relate seasonal-to-interannual changes in upper ocean heat content to surface heat forcing products from several sources, including remotely-sensed and reanalysis heat flux products and in situ shipboard measurements. Distinct differences in variability of heat content are found north and south of the Polar Front, where different physical mechanisms, including mesoscale eddies, contribute to the local heat budget. We explore how surface fluxes and differences in dynamical processes may contribute to cross-frontal differences in heat content variability.