FY 1993

A deep inertial jet on a sloping bottom near the equator

Johnson, G.C.

Deep-Sea Res. Pt. I, 40(9), 1781–1792, doi: 10.1016/0967-0637(93)90032-X (1993)

A previous model of an equatorward-flowing inertial jet over a sloping bottom gives an explanation for the great width of deep western boundary currents at mid-latitudes. The model has an inverted reduced-gravity semi-geostrophic shallow water configuration. Here this model is modified for consistency on the equatorial beta-plane to examine the jet as it approaches and then crosses the equator. The jet is scaled according to recent observations of an equatorward current of bottom water off the coast of East Africa near 3°S in the geometrically simple Somali Basin of the Indian Ocean. Model results are in reasonable agreement with observations south of the equator. Possible reasons for discrepancies between model and observations north of the equator include the violation of the semi-geostrophic approximation, frictional effect, and hydraulic jumps.