Energy Transfer Into the Deep Ocean from Mixed Layer Near-Inertial Currents Generated by Storms in the Bay of Bengal

Several field measurements around the globe have revealed near-inertial oscillations in the mixed layer excited by intermittent storms. The mechanisms leading to the decay of these near-inertial currents have been a subject of much interest in the last two to three decades. One such prominent mechanism is the propagation of these near-inertial oscillations into the deep ocean. In this talk, we adopt the approach of Moehlis and Llewllyn Smith (2008), which is based on the framework developed by Young and Ben Jelloul (1997), to model the downward propagation of near-inertial oscillations as an initial value problem. The initial conditions are set by a near-inertial current in the mixed layer generated by a storm that has just passed the region, and the focus is particularly on the time scale over which the mixed layer current decays and the depth of penetration of the energy in the near-inertial oscillations. Our specific advancements to the theory include incorporating a realistic stratification profile (representative of the Bay of Bengal) below the mixed layer, and the inclusion of a spatial structure for the initial velocity profile. The relevance and usefulness of the theory in describing some observations in the Bay of Bengal will be discussed.