A two-layer approximation to the Brazil Current-Intermediate Western Boundary Current System between 20 degrees S and 28 degrees S

Autor(es)

Fernandes, Alexandre M. ^{[1, 2]} ; da Silveira, Ilson C. A. ^[1] ; Calado, Leandro ^[3] ; Campos, Edmo J. D. ^[1] ; Paiva, Afonso M. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Oceanog, Dept Oceanog Fis Quim & Geol, BR-05580120 Sao Paulo - Brazil

^[2] Univ Estado Rio de Janeiro, Fac Oceanog, Dept Oceanog Fis, Rio De Janeiro - Brazil

^[3] Inst Estudos Mar Alm, Paulo Moreira, Marinha Brasil - Brazil

^[4] Univ Fed Rio de Janeiro, COPPE, Programa Engn Ocean, BR-21941 Rio De Janeiro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Ocean Modelling; v. 29, n. 2, p. 154-158, 2009.
• Citações Web of Science: 7

Resumo

It has been shown that the vertical structure of the Brazil Current (BC)-Intermediate Western Boundary Current (IWBC) System is dominated by the first baroclinic mode at 22 degrees S-23 degrees S. In this work, we employed the Miami Isopycnic Coordinate Ocean Model to investigate whether the rich mesoscale activity of this current system, between 20 degrees S and 28 degrees S, is reproduced by a two-layer approximation of its vertical structure. The model results showed cyclonic and anticyclonic meanders propagating southwestward along the current axis, resembling the dynamical pattern of Rossby waves superposed on a mean flow. Analysis of the upper layer zonal velocity component, using a space-time diagram, revealed a dominant wavelength of about 450 km and phase velocity of about 0.20 ms(-1) southwestward. The results also showed that the eddy-like structures slowly grew in amplitude as they moved downstream. Despite the simplified design of the numerical experiments conducted here, these results compared favorably with observations and seem to indicate that weakly unstable long baroclinic waves are responsible for most of the variability observed in the BC-IWBC system. (C) 2009 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 98/14850-4 - Investigacao dos efeitos topograficos no meandramento da corrente do brasil ao largo do sudeste brasileiro atraves da utilizacao do modelo de coordenadas isopicnais da universidade de miami.
• Beneficiário: Alexandre Macedo Fernandes
• Modalidade de apoio: Bolsas no Brasil - Mestrado