HR: 1400h
AN: A43C-05    [Abstracts]
TI: Negative ocean--atmosphere feedback in the South Atlantic Convergence Zone
AU: * De Almeida, R F
EM: roberto@dealmeida.net
AF: Centro de Previsao de Tempo e Estudos Climaticos, Instituto Nacional de Pesquisas Espaciais, Rod. Pres. Dutra, km 40, Cachoeira Paulista, SP 12630-000, Brazil
AU: Nobre, P
EM: pnobre@cptec.inpe.br
AF: Centro de Previsao de Tempo e Estudos Climaticos, Instituto Nacional de Pesquisas Espaciais, Rod. Pres. Dutra, km 40, Cachoeira Paulista, SP 12630-000, Brazil
AU: Haarsma, R J
EM: haarsma@knmi.nl
AF: Royal Netherlands Meteorological Institute, Postbus 201, De Bilt, 3730 AE, Netherlands
AU: Campos, E J
EM: edmo@io.usp.br
AF: Instituto Oceanografico, Universidade de Sao Paulo, Praca do Oceanografico, 191, Sao Paulo, SP 05508-120, Brazil
AB: The temporal evolution of the coupled variability between the South Atlantic Convergence Zone (SACZ) and the underlying sea surface temperature (SST) during austral summer is investigated using monthly data from the NCEP/NCAR reanalysis. A maximum covariance analysis shows that the SACZ is intensified [weakened] by warm [cold] SST anomalies in the beginning of summer, drifting northward. This migration is accompanied by the cooling [warming] of the underlying oceanic anomalies. The results confirm earlier analyses using numerical models, and suggest the existence of a negative feedback between the SACZ and the underlying South Atlantic SST field. A linear regression of daily anomalies of SST and omega at 500 hPa to the equations of a stochastic oscillator reveals a negative ocean--atmosphere feedback in the western South Atlantic, stronger during January and February and directly underneath the oceanic band of the SACZ.
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4263 Ocean predictability and prediction (3238)
DE: 4504 Air/sea interactions (0312, 3339)
DE: 4954 Sea surface temperature
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly