HR: 1330h
AN: OS23A-05    [Abstracts]
TI: Sea Surface Temperature Anomalies in the Western South Atlantic from 1982 to 2004
AU: * Lentini, C A
EM: lentini@io.usp.br
AF: Instituto Oceanografico da Universidade de Sao Paulo, Praca do Oceanografico, 191, Sao Paulo, SP 05508-120 Brazil
AU: De Almeida, R A
EM: roberto@dealmeida.net
AF: Instituto Oceanografico da Universidade de Sao Paulo, Praca do Oceanografico, 191, Sao Paulo, SP 05508-120 Brazil
AU: Arruda, W Z
EM: wilton@im.ufrj.br
AF: Instituto de Matematica da Universidade Federal do Rio de Janeiro, Av. Brigadeiro Trompowsky s/n Centro de Tecnologia, Bloco C, Rio de Janeiro, RJ 68530 Brazil
AU: Campos, E J
EM: edmo@io.usp.br
AF: Instituto Oceanografico da Universidade de Sao Paulo, Praca do Oceanografico, 191, Sao Paulo, SP 05508-120 Brazil
AB: Twenty-six years of satellite-derived sea surface data were used to investigate spatial and temporal variabilities of SST anomalies in the Southwestern Atlantic (SWA). The analysis is focused on the large scale variations over the continental shelf and slope region with depths ≤~1000-m, between 42°S and 22°S. The purpose of this paper is two-fold. First, it revisits the work done by Lentini el al. (2001) motivated by the extension of the time series of SST from 1994 to September 2004. Second, it investigates the relationship between SST anomalies in the area of study and the occurrence of ENSO events in the Pacific for the same period. Northward-propagating cold and warm anomalies have average speeds of the order of 20 cm/s. The relationship between northward-propagating SST anomalies and anomalous alongshore winds is also investigated. Southward-advected cold and warm anomalies, on the other hand, have slower speeds. Significant differences were observed in the SST anomalies during El~Niño (EN), La~Niña (LN) and Neutral years (NT). On average, EN years are characterized by warm SST anomalies in regions directly influenced by the Brazil Current, whereas LN years are marked by cool SST anomalies in the Brazil Current vicinity. The first EOF mode for the three along-shelf transects show an in-phase oscillation, indicating that the SST variations take place almost simultaneously throughout the entire region. Investigation of the temporal structure for the first two PCA's modes account for more than 65% of the non-seasonal variabiliy over the shelf. These results seem to confirm the correlation between ENSO events and the northward-propagating (southward-advecting) SST anomalies along the SWA.
DE: 3359 Radiative processes
DE: 4203 Analytical modeling
DE: 4275 Remote sensing and electromagnetic processes (0689)
DE: 4522 El Ni¤o
DE: 4546 Nearshore processes
SC: Ocean Sciences [OS]
MN: 2005 Joint Assembly