The present analysis examines the effects of the central Atlantic Niña (NCAN) and eastern Atlantic Niña (NEAN) modes on seasonal precipitation in South America (SA) and related atmospheric circulation during the 1951–2020 period. NCAN is the negative pole of broader Atlantic sea surface temperature (SST) modes: negative South Atlantic dipole (SAD) in all seasons, positive interhemispheric SST gradient (GRAD) in austral summer...

The isolated/combined impacts of the positive Indian Ocean Dipole (pIOD) and El Niño (EN) events on precipitation in South America (SA) were investigated during austral winter and spring for the 1901–2012 period, considering both Atlantic Multidecadal Oscillation (AMO) phases. Under the warm phase (WAMO), EN events are well characterised in winter and, in spring, are accompanied by anomalous warming of the Tropical North Atlan...

The present study examines the effects of the central Atlantic Niño (CAN) and eastern Atlantic Niño (EAN) events on the seasonal precipitation in South America (SA) during the 1951–2020 period. For the CAN during the summer and autumn, an interhemispheric sea surface temperature (SST) dipole mode induces an anomalous thermally direct circulation in the 10° N–10° S band and is the main factor causing precipitation anomaly patte...

Studies related to monitoring changes in frequency, intensity and duration of precipitation extremes are key to creating efficient climate change measures and forest conservation policies. This study describes new insights into rainfall precipitation extremes over the Amazon basin (AB) during the last four decades (1981–2021) from the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPSv2). Here we analysed t...

This study examines the Interdecadal Pacific Oscillation (IPO) modulation of the El Niño–Southern Oscillation (ENSO) teleconnections in its decaying stages with the tropical ocean by focusing on the Indian Ocean Basin‐Wide (IOBW) mode and the precipitation over South America (SA) in the 1901–2012 period. Composite analyses revealed that the ENSO teleconnections are IPO‐modulated due to the differential ENSO decaying speed, whi...

The effect of multiyear La Niña (LN) events on precipitation in South America (SA) was assessed considering 10 persistent LN events over two successive years, referred to as Y1 and Y2 for the 1901–2012 period. Y1 spans from the austral winter of the first year to autumn of the second year, and Y2 spans from the austral winter of the second year to autumn of the third year. Comparisons were performed season by season of the Y1...

This work proposes an adaptation of the method developed in previous papers to determine the onset and demise of the rainy season (ONR and DER) dates in the areas of the South American monsoon system (SAMS) based on the pentad antisymmetric outgoing long‐wave radiation (AOLR). In those papers, the sign change of the mean AOLR in the central Amazon Basin (CAM) and western central Brazil (WCB) from positive to negative defined t...

This paper examines the oceanic mean states associated with the Pacific decadal oscillation (PDO) and the Atlantic multidecadal oscillation (AMO) and their relations to the El Niño (EN). The mean states refer to the simultaneous occurrences of warm (W) and cold (C) phases of these oscillations: WAMO/CPDO, CAMO/WPDO and CAMO/CPDO. In general, the sea surface temperature (SST) anomaly patterns of the mean states show a combinati...

The Eastern Pacific (EP) and Central Pacific (CP) El Niño‐Southern Oscillation (ENSO) types and their impacts on the tropical North Atlantic (TNA) SST variability and 15°N–15°S South American precipitation during the warm and cold phases of the Atlantic Multidecadal Oscillation (WAMO and CAMO) were evaluated during the 1901–2012 period. The results show more frequent ENSO events during the CAMO. The El Niño (EN) (La Niña [LN])...

This paper examines the climate variability modes in the South American/Atlantic sector accompanying dry and wet years over north‐eastern Brazil ( NEB ) in which the tropical Pacific and Atlantic oceanic‐atmospheric conditions usually associated, respectively, with dryness and wetness are absent. The analyses are for several variables and take into account the warm and cold Atlantic Multidecadal Oscillation ( AMO ) phases ( WA...

This paper analyses the relations between the El Niño/Southern Oscillation (ENSO) mode in the tropical Pacific and the sea surface temperature (SST) modes in the South Atlantic for the 1900–2006 period. In the South Atlantic, two modes are analysed in more detail: the South Atlantic dipole (SAD) mode, with centres at (15°S, Greenwich longitude) and at (37.5°S, 25°W) and the southwestern South Atlantic (SWSA) mode, with centres...

A new method to determine the onset dates of the rainy season (ONR) in the Central Amazon area using the antisymmetric in relation to the equator outgoing longwave radiation (OLR) data was developed in a previous paper. This method is adjusted and used here to determine the ONR in Western‐Central Brazil (WCB). The adjustment is needed because of the northwest‐southeast (NW‐SE) orientation of the American monsoon‐related convec...

Moisture and heat budgets in selected areas of the South American monsoon system (SAMS) and the equatorial Atlantic are examined for the 1979–2006 period. These areas are the Central Amazon (CAM), western Central Brazil (WCB), South Atlantic convergence zone (SACZ) and the Atlantic inter‐tropical convergence zone (ITCZ). The moisture and heat budget terms are calculated using daily reanalyzed data, and filtered for the 0.4–1.2...

The anomaly patterns of rainfall in South America for El Niño/Southern Oscillation (ENSO) extreme conditions stratified according to the high, low, and normal Pacific (inter‐) Decadal Oscillation (PDO) phases (HPDO, LPDO and NPDO) are examined for the three bi‐months of the season from November to April. El Niño (EN) and La Niña (LN) composites as well as the linear (EN − LN) and nonlinear (EN + LN) components of the precipita...