A planetary boundary-layer model for the Somali jet.

Abstract

A baroclinic boundary layer of cross-equatorial flow over the Arabian Sea is investigated with a fine-mesh (200 m) vertical resolution numerical model. The principal results of the study include a realistic simulation of the vertical structure of the cross-equatorial flow. The balance of forces and boundary-layer transitions betwen strong cross-equatorial flow, the low-level jet and at ITCZ over the northern Arabian Sea are analyzed in some detail. We note that an advective boundary layer is dominant across the equator, and the core of the low-level jet is located toward the poleward edge of the advective boundary layer. North of this region a gradual increase of upward motion is noted and this region is identified as the Intertropical Convergence Zone (ITCZ).- from Authors