Large-scale vertical momentum, kinetic energy and moisture fluxes in the antarctic sea-ice region

• Published in: Boundary-Layer Meteorology
• Main Authors: Simmonds, Ian, Rafter, Anthony, Cowan, Timothy, Watkins, Andrew B., Keay, Kevin
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Springer 2005
• Subjects: Antarctica; Extratropical cyclones; Fluxes over the sea-ice zone; Large-scale turbulence; NCEP re-analysis; Sea ice; Antarctic; The Antarctic; Antarc*
• Online Access: https://research.usq.edu.au/item/z09zx/large-scale-vertical-momentum-kinetic-energy-and-moisture-fluxes-in-the-antarctic-sea-ice-region; https://doi.org/10.1007/s10546-004-5939-6

There are very strong thermal gradients between the Antarctic continent and the sea-ice zone, and between that zone and the ocean to the north. As a result of these contrasts the sea-ice domain is one of strong cyclogenesis and high cyclone frequency. In this study we explore many aspects of that cyclonic behaviour and investigate the manner in which these systems influence, and are influenced by, the sea ice. Using the NCEP-DOE re-analyses (1979–2002) we have determined variables that are proportional to the mean of the wind stress and the mean rate at which mechanical energy is imparted to the surface. Using two decompositions of the wind field we have obtained estimates of how much of these fluxes are contributed to by the transient eddies. We find these to be significant over the sea ice and the ocean to the north, particularly when a new decomposition is used. The presence of frequent and vigorous cyclones is a central factor that determines the positive mean freshwater flux over the sea-ice zone in all seasons. This transfer to the ocean is smallest in summer (0.49 mm day−1) and assumes a maximum of 1.27 mm day−1 in winter.