HR: 1400h
AN: OS23C-01    [Abstracts]
TI: A Numerical Study of the Impact of Changes in Antarctic Sea-Ice on the Brazil Malvinas Confluence Region
AU: * Pereira, J
EM: janini@usp.br
AF: University of Sao Paulo, Praca do Oceanografico, 191 sala 166, Sao Paulo, SP 05508-120, Brazil
AU: Wainer, I
EM: wainer@usp.br
AF: University of Sao Paulo, Praca do Oceanografico, 191 sala 166, Sao Paulo, SP 05508-120, Brazil
AU: Raphael, M
EM: raphael@geog.ucla.edu
AF: University of California, Los Angeles, 1255 Bunche Hall, Los Angeles, CA 90095-1524, United States
AU: Mata, M M
EM: mauricio.mata@furg.br
AF: Foundation Federal University of Sao Paulo, Rua Eng. Alfredo Huch, 475, Rio Grande, RS 96201-900, Brazil
AB: The Brazil Malvinas Confluence (BMC) region , where the warm and salty southward flowing Brazil current encounters the cold and less saline northward flowing Malvinas current, is considered one of the most energetic of the world ocean. This study investigates the sensitivity of the BMC, considered here from 38-44°S, to changes in extreme Antarctic sea-ice concentration using the NCAR-CCSM3 coupled model. Three simulations with 150 years for sea ice concentration (SIC) with maximum (MAX), minimum (MIN) and control climatologies (CTRL) from satellite-derived data were analyzed to determine the response of the ocean circulation to sea-ice extent forcing. The SST values for the SIC MIN experiment exhibit temperature 1°C warmer than the SST for the SIC CTRL experiment results around 42°S. However, the SST results for SIC CTRL shows temperature of 1.5°C warmer than the values for the results obtained using SIC MAX for the same location. It is also seen in the mean temperature of the upper 500m also at 42°S that the higher temperatures in the SIC MIN experiment are associated with a southward displacement of the BMC. Analyses of the barotropic transport shows an intensification of 5Sv in the SIC MAX western boundary circulation at 44°S relative to the SIC CTRL results. Differences in the transport for, SIC MIN relative to the control experiment is only 2Sv. The transport intensification observed is directly correlated with the intensification of the winds in the SIC MAX. Correlations between the wind stress curl and the barotropic transport, for the SIC MAX, MIN and CTRL in the BMC region is -0.68, -0.83 and -0.85, respectively.
DE: 4215 Climate and interannual variability (1616, 1635, 3305, 3309, 4513)
DE: 4219 Continental shelf and slope processes (3002)
DE: 4223 Descriptive and regional oceanography
DE: 4262 Ocean observing systems
DE: 4283 Water masses
SC: Ocean Sciences [OS]
MN: 2007 Joint Assembly