How does evaporation influence the circulation of water in the Persian Gulf?

Evaporation plays a critical role in the vertical water circulation of the Persian Gulf. Because the gulf experiences high temperatures and receives only a limited influx of fresh water, the rate of evaporation significantly exceeds the amount of freshwater inflow.1

This process directly influences the density of the water: as surface water enters the gulf from the Indian Ocean, it is subjected to intense evaporation. This causes the water to become increasingly saline and dense. Consequently, this denser, saltier water sinks and flows back out into the Indian Ocean beneath the incoming surface layer, establishing a distinct vertical, counterclockwise circulation pattern.1