HR: 11:50h
AN: OS31D-07    [PDF]
TI: The Ocean Circulation of the Ross Sea, Antarctica during the 1990s
AU: * Van Woert, M L
EM: mvanwoert@natice.noaa.gov
AF: National Ice Center, NOAA/NESDIS/OSDPD E/SP 5200 Auth Rd, FOB-4, Rm 1069, Suitland, MD 20746 United States
AB: During the 1990s several major United States and Italian research programs worked concurrently in the Ross Sea. Here we take advantage of recent hydrographic and current meter data collected over the Ross Sea continental shelf to describe the ocean circulation and its interannual variability during the 1990s. The hydrographic data reveal a well-defined cyclonic gyre in the southwest Ross Sea and in many locations this result is supported by direct current meter observations. The most notable departure from the simple circulation pattern portrayed by the hydrographic data occurred in the Ross Sea Polynya where strong, wind-forced, upper-ocean flow opposed the baroclinic circulation. The atmospheric circulation over the Ross Sea during the 1990s appears to have been strongly modulated on interannual time scales by the El Ni¤o-Southern Oscillation (ENSO) phenomenon. Evidence is presented here suggesting that the upper-ocean currents within the Ross Sea Polynya respond on interannual time scales to changes in the strength of the imposed wind forcing (i.e. years with stronger atmospheric forcing appear to have stronger upper-ocean flow). Sea ice adjacent to the Ross Ice Shelf (RIS) also varied on interannual time scales and achieved its minimum values during 1996 and 1999, the two La Ni¤a years. Ocean currents near the shelf break (mooring B') during those two years showed northward export of a thick layer of shelf water, presumably in response to stronger buoyancy forcing near the RIS. In contrast, large changes in the near-bottom shelf flow north of Ross Island (mooring A'/Adelie) occurred during 1997-1999 roughly in phase with the development and later relaxation of the 1997/1998 El Ni¤o. It is suggested that remote forcing through interactions with the subice cavity are responsible for the observed interannual changes at A'/Adelie.
DE: 4207 Arctic and Antarctic oceanography
DE: 4215 Climate and interannual variability (3309)
DE: 4219 Continental shelf processes
DE: 4223 Descriptive and regional oceanography
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting