Wind-induced reversal in Red Sea circulation

Abstract

The monsoon reversal in the Red Sea circulation near and above sill depth is described and related to the winds at the sea surface. During winter (October–May), the surface waters flow north, sink in the northern Red Sea, and return to the south as a warm, high-salinity subsurface current that flows out over the shallow sill into the Gulf of Aden. During summer (June–September), the pattern reverses: i.e. the surface waters of the Sea flow south, causing upwelling in the northern Red Sea, while in the southern Red Sea a subsurface inflow over the shallow sill of cool, low-salinity Gulf of Aden water occurs. This reversal in circulation is closely associated with reversals in the monsoon winds acting at the sea surface and the resulting changes in sea level in the southern Red Sea and Gulf of Aden.