Donguy Jean-René auteur aut IRD Meyers G. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Dynamic height was calculated from XBTs collected along several shipping routes in the western Indian Ocean. In the northern hemisphere, low dynamic heights prevail during the NE monsoon and high dynamic heights during the SW monsoon inducing an alternating Somali Current. In the southern hemisphere, at 7°-8° S a trough of low dynamic height occurs during the whole year. EOF analysis is used to document the variation of these features. The geostrophic transports calculated for the XBT routes show spatially coherent patterns with strong seasonal variations. In the Arabian Sea, an anticlockwise gyre develops during the NE monsoon alternating with a clockwise gyre during the SW monsoon. Between 5°N and 5°S, the transport variations show eastward flow twice each year during the monsoon transitions, except on the western most route where the annual variations of the gyre in the Arabian Sea extend to the equator. The mean transport of the South Equatorial Current increases regularly with longitude from east to west in all months. It has small annual variations, and the phase of the annual maximum progresses consistently westward. (Résumé d'auteur) specialized COURANT GEOSTROPHIQUE HYDRODYNAMIQUE VARIATION SAISONNIERE 032DYNEAU 42 6 1007-1028 1995 0967-0637 https://www.documentation.ird.fr/hor/fdi:010007560 0967-0637 [F B010007560] https://www.documentation.ird.fr/hor/fdi:010007560 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_45-46/010007560.pdf IRD - Base Horizon / Pleins textes 1996-11-25 2006-05-27 fdi:010007560 fre