Arabian Sea Cooling: A Preliminary Heat Budget

Abstract

To assess the importance of possible feedbacks between ocean and atmosphere in the Arabian Sea, we computed a preliminary heat budget for the upper ocean layer. The observed total heat loss during the Southwest Monsoon between April and August is essentially balanced by three phenomena: positive heat gain from the atmosphere, negative northward heat flux across the equator, and heat loss due to upwelling along the coasts of East Africa and Arabia. Upwelling constitutes the dominant factor and the question is discussed as to which processes replenish the cold upwelled water on a seasonal time scale. The average annual heating rate above and beyond seasonal fluctuations is found to be 24 W m?2. This net heat input must be compensated by ocean currents. The manner in which the ocean accomplishes this remains to be clarified.