HR: 0800h
AN: OS41B-0534    [Abstracts]
TI: What are the Physical Processes Driving Sea Surface Temperature and Salinity Changes at Interannual Timescales in the Southwestern Tropical Pacific Ocean?
AU: * Cravatte, S E
EM: sophie.cravatte@ird.fr
AF: IRD/LEGOS, 14 avenue edouard BELIN, TOULOUSE, 31400, France
AU: Kessler, W S
EM: william.s.kessler@noaa.gov
AF: NOAA/PMEL/OCRD, 7600 Sand Point Way NE, SEATTLE, WA 98115, United States
AU: Menkes, C E
EM: christophe.menkes@noumea.ird.fr
AF: IRD/NOUMEA, 101 Promenade Roger Laroque Anse Vata, NOUMEA, 98848, New Caledonia
AU: Marchesiello, P
EM: Patrick.Marchesiello@ird.fr
AF: IRD/NOUMEA, 101 Promenade Roger Laroque Anse Vata, NOUMEA, 98848, New Caledonia
AB: Although the most prominent signature of the El Nino-Southern Oscillation is seen in the equatorial Pacific Ocean, significant interannual variability correlated with the equatorial signal is also observed in the southwestern subtropical Pacific. The sea surface is saltier and colder during El Nino than during La Nina events. In the course of El Nino events, the South Pacific Convergence Zone is displaced northeastward, producing interannual variability of the wind speed, wind curl, and the atmospheric heat and freshwater fluxes in the southern subtropics. The mean currents and thermocline depth of the southern gyre are also modified, and the oceanic advection terms are changed in consequence. To diagnose the relative importance of the physical processes driving the sea surface changes, the outputs of an ocean general circulation model are used and validated against the available data. The mixed layer heat and salt balances at interannual timescales are estimated. It appears that the deepening of the mixed layer during El Nino events is of primary importance to explain the surface modifications.
DE: 4504 Air/sea interactions (0312, 3339)
DE: 4522 ENSO (4922)
DE: 4572 Upper ocean and mixed layer processes
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting