Circulation of the Arabian Gulf : a three-dimensional study

Abstract EN

The physics of the Gulf waters is poorly understood, and there is a need to identify the roles of density forcing and wind in maintaining the long-term circulation pattern.

The circulation system is studied here using a three-dimensional primitive-equation model.

The model employs an idealized basin and is forced by positive buoyancy at the Strait of Hormuz, evaporation at the sea surface and an average northwesterly wind field of 5 m/s.

A prominent mechanism in the dynamics of establishment of the Gulf circulation system is the excitation of long and short topographic Rossby waves (TRW) by the density current.

The lowest mode of the long trapped TRW (or Continental Shelf Waves) along the Arabian sloping side triggered by the fresher water intrusion retards the progression of the density current along the Iranian coast.

The short TRW induce upwelling over the Arabian shelf which is stronger than the downwelling motion induced by evaporation.

The quasi-steady flow and salinity patterns, in three dimensions, are in general agreement with the available field observations when evaporation, fresher water inflow and wind are all included in the model.