Relationships between rainfall anomalies over northeastern Brazil and the El Niño–Southern Oscillation

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Abstract

[1] In this paper, sea surface temperature (SST) and sea level pressure variability modes associated with climate extremes (droughts and floods) over northeastern Brazil (NEB) stratified according to the El Niño–Southern Oscillation (ENSO) phases (El Niño, La Niña, and neutral) are reexamined. The analyses indicate that only 36% of the time an ENSO-based forecast for the NEB climate would be right. This relatively low percentage is mostly because the interannual variations of the NEB climate are more closely tied to the tropical South Atlantic SST variability modes than to the tropical Pacific variability mode. An interesting aspect revealed in the present analysis is that hints of the February–April SST anomaly patterns in the tropical Atlantic for dry and wet cases which are not directly related to the ENSO can be found months prior to the NEB rainy season. Since these hints are particularly strong in the tropical South Atlantic, the SST variations in this sector during months prior to the rainy season should be carefully monitored in the diagnostic activities.

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