Air-sea interaction and the seasonal cycle of the subtropical anticyclones ...

• Main Authors: Seager, Richard, Murtugudde, Ragu, Naik, Naomi H., Clement, Amy, Gordon, Neil, Miller, Jennifer
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2003
• Subjects: High pressure systems Meteorology; Ocean-atmosphere interaction; Ocean temperature; Atmospheric circulation; Pacific; North Atlantic
• Online Access: https://dx.doi.org/10.7916/d8-aysy-p883; https://academiccommons.columbia.edu/doi/10.7916/d8-aysy-p883

The causes of the seasonal cycles of the subtropical anticyclones, and the associated zonal asymmetries of sea surface temperature (SST) across the subtropical oceans, are examined. In all basins the cool waters in the east and warm waters in the west are sustained by a mix of atmosphere and ocean processes. When the anticyclones are best developed, during local summer, subsidence and equatorward advection on the eastern flanks of the anticyclones cool SSTs, while poleward flow on the western flanks warms SSTs. During local winter the SST asymmetry across the subtropical North Atlantic and North Pacific is maintained by warm water advection in the western boundary currents that offsets the large extraction of heat by advection of cold, dry air of the continents and by transient eddies. In the Southern Hemisphere ocean processes are equally important in cooling the eastern oceans by upwelling and advection during local winter. Ocean dynamics are important in amplifying the SST asymmetry, as experiments with ...