Análise da influência dos niños do Atlântico na variabilidade da posição latitudinal da ZCIT atlântica.

Abstract

The main objective of this study is to identify a possible relationship between the Benguela Current and the variability of Sea Surface Temperature (SST) anomalies in the equatorial Atlantic Ocean. Positive or negative climatological SST anomalies may play an important role in the anomalous latitudinal displacement of the Intertropical Convergence Zone (ITCZ) in the Tropical Atlantic Ocean. Monitoring is necessary because the ITCZ is one of the main precipitation producing systems in the northeastern region of Brazil (NEB) and depending on its latitudinal positioning the northern part of the NEB may experience periods of severe drought or major flooding. Monthly data were analyzed for the zonal (u) and meridional (v) components of surface wind, mean sea level pressure and TSM. The data set of the variables used was extracted from the ERA-Interim reanalysis, European Center for Medium-Range Weather Forecast (ECMWF) at 00 UTC, 06 UTC, 12 UTC and 18 UTC with spatial resolution of 0.75 ° x 0.75 ° for the period from January 1989 to December 2018. The study area to represent the performance of the Benguela Current is located between 2°E; 14.75°E; 6.5°S; 32°S, with a division of 17,75°S, comprising the latitude of the westernmost African coast in the Benguela Current area. The area between 0-5ºS and 30ºW-10ºW was chosen for South Equatorial Atlantic SST analysis. The region between 18ºN-12ºS and 40ºW-10ºW is the area of activity of the ITCZ. The results showed that there is a correlation between the Atlantic Niños, and this correlation is more pronounced between the northern area of the Benguela Niño and the Equatorial Atlantic Niño. Cold Niños in the Equatorial Atlantic make the Trade Zone Confluence Zone positioned north of its average climatological position, while hot Niños produce the displacement of the Trade Zone Confluence to the south. Pressure deviations at mean sea level in the area of the high pressure center of the South Subtropical Atlantic tend to influence the SST in the Niños de Benguela and the Equatorial Atlantic, that is, a more intense subtropical rise than the average leads to the cooling of the SST in the areas of Ninos, possibly due to the intensification of trade winds off the coast of Africa and the Central Equatorial Atlantic, while a weaker subtropical rise produces an increase in SST in the Niños areas due to the weakening of trade winds.