Local influence on the SE trades of the west Indian Ocean

Abstract

Attempt has been made to explain the local variations of the SE trades in the lower levels during the northern summer at Diego-Suarez in Malagasy, Garissa in Kenya and Socotra in the west Arabian Sea. At Diego-Suarez the trades experience local acceleration which is ascribed to the increased pressure gradient caused by the Malagasy barrier, Kenya is situated east of the African barrier where, to the north of the equator, a. pressure trough and to the south 11 pressure ridge are produced by the barrier, From the ridge to the trough an organised flow of air takes place up to north Somalia, This flow, across the equator over Kenya, can accelerate when the trough ridge system intensifies, In the area of Socotra the thermally controlled pressure gradient is considered mainly responsible fur the increased wind speed. Importance of the African barrier on the Indian monsoon is also discussed.