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 102J.m-3. The estimated Rosby radius of internal deformation compared well with the diameter of the eddy (approx. 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 102J.m-3) was more than twice of that in the northward flow (1.0 x 102J.m-3). The study also indicated that the eddy obtained its energy from the APE produced mainly from the southward flowing boundary current