Transporte de volume e condições hidrográficas no Canal de São Sebastião / Volume transport and hydrographic conditions in the São Sebastião Channel

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Current data obtained using an "Acoustic Doppler Current Profiler " (ADCP) towed by a research boat and nearly synoptic hydrographic data were sampled in the São Sebastião Channel (SSC) during six cruises between 2001 and 2006. This study also uses ocean-surface wind fields for the South Brazil Bight (SBB) area derived from the QuikSCAT scatterometer. The method of objective analysis was applied to obtain the horizontal and vertical distributions of temperature, salinity, density, velocity and wind. The estimated along-channel volume transport for the four vertical sections arranged radially to the channel was almost continuous or discontinuous between their values, probably mainly caused by the occurrence of anticyclonic or cyclonic gyres in the southern portion of the SSC and almost synopticity in data acquisition. The calculated volume transport in the channel ranged from 18,904 m3 s1 on 13/11/2002 heading north forced by southwesterly winds, to -1,959m3 s1 on 27/07/2006 heading south forced by northeasterly winds. Gyres were observed only in the southern portion of the channel. These gyres were cyclonic during northeasterly winds and anticyclonic during southwesterly winds. The water renewal time of the SSC varies from 0.81 to 7.81 days. On 27/07/2006, 10/10/2006 and 14/12/2006, bidirectional circulation in two layers was observed, with surface currents heading SW, forced by northeasterly winds, and deep currents heading N. On 14/12/2006 the whole bottom layer of the SSC was filled with South Atlantic Central Water (SACW), and its coastal upwelling was observed at the southern continental coast of the channel, probably due to NE/SE winds that blew between 8/12/2006 and 14/12/2006.

ASSUNTO(S)

sã sebastião channel transporte de volume canal de são sebastião volume transport

ACESSO AO ARTIGO

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