Tropical Pacific and South Atlantic effects on rainfall variability over Northeast Brazil

Authors

  • Rita Valéria Andreoli,

    Corresponding author
    1. Instituto Nacional de Pesquisas Espaciais, Centro de Previsão de Tempo e Estudos Climáticos, Avenida dos Astronautas, 1758, 12227-010 São José dos Campos, SP, Brasil
    • Instituto Nacional de Pesquisas Espaciais, Centro de Previsão de Tempo e Estudos Climáticos, Avenida dos Astronautas, 1758, 12227-010 São José dos Campos, SP, Brazil
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  • Mary Toshie Kayano

    1. Instituto Nacional de Pesquisas Espaciais, Centro de Previsão de Tempo e Estudos Climáticos, Avenida dos Astronautas, 1758, 12227-010 São José dos Campos, SP, Brasil
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Abstract

The present paper reexamines the relative role of the tropical Pacific and tropical South Atlantic (TSA) on the rainfall over Northeast Brazil (NEB). For several variables, El Niño-Southern Oscillation (ENSO) and TSA-related anomalous patterns are obtained. These patterns are then compared to the combined ENSO and TSA-related patterns to infer the relative importance of the two oceanic basins on the rainfall over NEB. Analyses are done for austral summer and autumn seasons. Considering the composite technique, six cases are examined: El Niño and neutral conditions in the TSA, La Niña and neutral conditions in the TSA, ENSO neutral conditions and warm TSA, ENSO neutral conditions and cold TSA, El Niño and warm TSA, and La Niña and cold TSA. The most important result comes from the cases with competing influences of the tropical Pacific and the TSA. In some of these cases, the SST variability in the TSA is the determining factor of the NEB climate. The result of this study might be useful mainly for regional climate monitoring purposes. Copyright © 2006 Royal Meteorological Society.

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