Wintertime Air-Sea Interaction

off the East Coast of North America


Intensification of winter cyclones over the ocean and the corresponding oceanic response are some of the most challenging problems in air-sea interaction. Climatologically, the largest transfers of sensible and latent heat from the ocean to the atmosphere occur off the east coast of the United States along the Gulf Stream SST front during winter. A substantial part of these transfers takes place during the cold-air outbreak phase of a passing winter storm. As cold, dry, Arctic air flows off of the continent and over the warm Gulf Stream, instantaneous transfer rates can exceed climatological values by several times (Xue et al., 1995). The significant contribution of these storms to the overall transfer of heat from the ocean to the atmosphere manifests the important role of the western boundary currents of the subtropical gyres in the poleward transport of heat by the ocean-atmosphere system.