Esta disponível online a partir de hoje o primeiro trabalho publicado pelo inctAmbTropic: “Intraseasonal variability of the North Brazil Undercurrent forced by remote winds. Autores: D. Veleda, M. Araujo, R. Zantopp,e R. Montagne“. O trabalho foi publicado no volume 117 do Journal of Geophysical Research. O professor Moacyr Araújo coordena o GT3.2 (Ciclos Biogeoquímicos, Fluxo de CO2 e Acidificação do Oceano Atlântico Tropical) e é membro do Comitê Gestor do inctAmbTropic, representando a área de Oceanos.
Schematic representation of the Atlantic Subtropical Cell (STC) circulation, including subduction (blue) and upwelling (green) zones. Current branches involved in the STC flows are NEC, SEC, sSEC, NECC and EUC; NEUC, SEUC = North and South Equatorial Undercurrent; NBC, NBUC = North Brazil Current and Undercurrent; GD, AD = Guinea and Angola domes. Interior equatorward thermocline pathways dotted. Adapted from Schott et al. . The mooring array at 11S is shown by the red line.
ABSTRACT: “Intraseasonal signals with periods of 2 to 3 weeks in near-surface alongshore current measurements are detected from four moorings (K1–K4) deployed from 2000 to 2004 at the 11S section close to the Brazilian coast as part of the German CLIVAR Tropical Atlantic Variability Project. This section crosses the path of the North Brazil Undercurrent, the most powerful western boundary current in the South Atlantic Ocean. We investigate the origin of this intraseasonal variability of the North Brazil Undercurrent by relating the oceanic oscillation of the alongshore currents to its atmospheric counterpart, the meridional wind stress. On average, the results indicate a well-defined lagged (10 days) correlation (˜0.6) structure between meridional wind stress and alongshore currents. The oceanic region with the highest cross-correlations is identified as a relatively narrow band along the Brazilian coast, from 22–36S and 40–50W, bounded in the north by an eastward change in coastline orientation. The cross-wavelet transform establishes the common power between the time series of meridional wind stress and alongshore currents, predominantly during austral winter and spring. These signals propagate equatorward with an alongshore speed of 285+/-63 km day1, consistent with Coastal Trapped Wave theory“.
Veleda, D., M. Araujo, R. Zantopp, and R. Montagne (2012), Intraseasonal variability of the North Brazil Undercurrent forced by remote winds, J. Geophys. Res., 117, C11024, doi:10.1029/2012JC008392. (para baixar o pdf, clique neste link)
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