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

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 FebruaryApril 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.Citation: Kayano, M. T., and R. V. Andreoli (2006), Relationships between rainfall anomalies over northeastern Brazil and the El Niño -Southern Oscillation,

Interannual relations between South American rainfall and tropical sea surface temperature anomalies before and after 1976

“…Furthermore, the TSA index acted to weaken (enhance) the negative ENSO relations with the precipitation over northeastern South America, for the 1948-1976 (1977-2002) period. The first case certainly includes the competing effects of the ENSO teleconnections and the regional SST anomaly pattern in the TSA in the rainfall over northeastern Brazil, described previously by Kayano and Andreoli (2006).…”

“…Studies in this context focused specific regions, like northeastern Brazil (Giannini et al, 2004;Andreoli and Kayano, 2006;Kayano and Andreoli, 2006) and southeastern South America (Diaz et al, 1998;Barros and Silvestri, 2002). So, an analysis of the relative role of the Pacific and Atlantic Oceans on the climate variability of South America considering a broader continental area is still necessary.…”

Avaliação Da Seca De 2005 E 2010 Na Amazônia: Análise Da Bacia Hidrográfica Do Rio Solimões

“…Durante o mecanismo de anômalo de TSM no Atlântico tropical ramo ascendente da célula de Walker pode alterar o acoplamento oceano-atmosfera de um evento de El Niño no Pacífico equatorial, modificando-o para o fenômeno de La Niña, configuração inversa para evento de La Niña (ENFIELD; MAYER, 1997; KAYANO et al 2006). Esses mecanismos de teleconexões foram observados nos anos seguintes as duas estiagens aqui estudadas (cheias de 2006 e 2011).…”

Oceanic influence on the precipitation in Venezuela under current and future climate

“…Martelo (2003a) discovered that northern Venezuela is more strongly influenced by the Atlantic, and eastern Venezuela more by the Pacific. Kayano and Andreoli (2006) investigated the oceanic influence on the northeastern Brazilian rainfall and came to the conclusion that the influence of ENSO is much weaker than the effect of the Tropical South Atlantic.…”