Energy and generating mechanism of a subsurface, cold core eddy in the Bay of Bengal

Abstract

Computation of available potential energy (APE) of a recently observed cold core, subsurface eddy (centered at 17-degrees-40'N and 85-degrees-19'E) in the Bay of Bengal revealed that the energy maxima associated with the eddy was of the order of 1.31 x 10(2) J.m-3. The estimated Rosby radius of internal deformation compared well with the diameter of the eddy (congruent-to 200 km). The prevailing current system during the period of observation of the eddy was a southerly flow along the northwestern boundary forced by fresh water influx and a northerly flow along the southwestern boundary generated by wind forcing. The study showed that the energy density associated with the southward advective current (2.5 x 10(2) J.m-3) was more than twice of that in the northward flow (1.0 x 10(2) J.m-3). The study also indicated that the eddy obtained its energy from the APE produced mainly from the southward flowing boundary current.