Reverse Estuarine Circulation

Reverse estuarine circulation is the inverse-estuary pattern of evaporation-dominated basins, where surface inflow brings in lighter ocean water and a dense, saline outflow leaves at depth, the opposite of a classic estuary fed by river runoff. It develops where evaporation exceeds precipitation and runoff, raising surface salinity and density until the dense water sinks and exits over the sill. The Mediterranean is the textbook case: Atlantic water flows in at the surface through Gibraltar while saline Mediterranean Outflow Water leaves below. The Red Sea and Persian Gulf show the same inverse exchange.