Variations of Sea Surface Temperature, Wind Stress, and Rainfall over the Tropical Atlantic and South America

The role of North Brazil Current transport in the paleoclimate of the Brazilian Nordeste margin and paleoceanography of the western tropical Atlantic during the late Quaternary

“…Likewise, anomalously warm conditions in the southern tropical Atlantic tend to delay the northward migration of the ITCZ and generate wetter-than-normal conditions in the northern Nordeste. These precipitation anomalies can occur on a variety of timescales including intra-annual (e.g., Marengo et al, 2008 andLewis, et al, 2010), decadal (e.g., Hastenrath andHeller, 1977 andShukla, 1996), and, perhaps, centennial/millennial (e.g., Cruz et al, 2009 and this paper). Thus, we posit that the centennial-millennial detrital-rich intervals represented by the Ti/Ca peaks were produced by centennial-millennial increases of regional rainfall that coincided with a cooler northern tropical Atlantic, warmer southern tropical Atlantic, and an anomalously southward-displaced mean position of the ITCZ.…”

“…Precipitation in the northern Nordeste during the instrumental period has long been related to, and is well correlated with, oceanographic conditions offshore (e.g., Hastenrath and Heller, 1977, Hastenrath, 1991, Ward and Folland, 1991and Nobre and Shukla, 1996. The majority of annual rainfall in the northern Nordeste occurs in March and April, when the ITCZ annually reaches its southernmost position.…”

“…The majority of annual rainfall in the northern Nordeste occurs in March and April, when the ITCZ annually reaches its southernmost position. Meridional variability of the ITCZ is associated with changes in the tropical Atlantic SST gradient that steer cross-equatorial wind anomalies from the cooler to the warmer hemisphere (Nobre and Shukla, 1996).…”

On the influences of the El Niño, La niña and Atlantic Dipole Paterni on the Amazonian Rainfall during 1960-1998

“…Some of these systems are mainly related to the seasonal cycle of atmospheric circula tion, such as the Bolivian upper-tropospheric high (Kousky and Kayano, 1981;Jones and Horel, 1990) and the Intertropical Convergence Zone (ITCZ). The ITCZ migrates southward during the austral summer and autumn inducing widespread precipitation mainly in the center-eastern Amazon by the end of the summer and begin ning of the autumn (Nobre and Shukla, 1996). Cold fronts originat ing in the austral extratropics may also affect convection in the Amazon.…”

The last deglaciation of Peru and Bolivia

“…Seasonal rainfall variability in the tropical Andes is linked to the position of the Intertropical Convergence Zone (ITCZ) over the Pacific and Atlantic Oceans, and by the strength of the South American Summer Monsoon (SASM) over the Amazon Basin (Zhou and Lau, 1998;Maslin and Burns, 2000;Maslin et al, 2011;Vuille et al, 2012). Inter-annual and multi-decadal rainfall patterns and temperature fluctuations over South America are affected by variability in mean-state conditions in the Atlantic and Pacific Oceans (Johnson, 1976;Nobre and Srukla, 1996;Henderson et al, 1999;Vuille et al, 2000;Bradley et al, 2003;Vuille and Werner, 2005). For example, the warm phase of the El Niño Southern Oscillation (ENSO) typically produces higher wet season rainfall amounts at low elevations along the Pacific coast of the central Andes, and the opposite during cold phases (Coelho et al, 2002).…”