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Madagascar: A pacemaker for the Agulhas Current system?
Author(s) -
Penven P.,
Lutjeharms J. R. E.,
Florenchie P.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl026854
Subject(s) - boundary current , current (fluid) , geology , eddy , oceanography , ocean current , indian ocean , structural basin , climatology , wind stress , geography , paleontology , meteorology , turbulence
Western boundary currents are driven by zonally integrated wind‐stress curl over the width of subtropical basins. This cross‐basin integration is interrupted in the South Indian Ocean where Madagascar presents a formidable barrier. Nevertheless, a western boundary current has been thought to exist in the Mozambique Channel, the Mozambique Current. Recent observations have however shown that no such current exists and that the flow in the channel instead consists of a train of eddies. Is this western boundary anomaly due to the presence of Madagascar? We have used a primitive equations model to investigate the flow in the South West Indian Ocean as if there were no Madagascar. We show that a normal, continuous western boundary current is then formed that constitutes a continuum with the Agulhas Current. The presence of Madagascar is shown to affect the frequency of inter‐ocean exchange events south of Africa.