Energetics during eddy shedding in the Gulf of Mexico

Abstract

Using the Estimating Circulation and Climate of the Ocean (ECCO) Phase II product, this study investigates the energetic characteristics during eddy shedding in the Gulf of Mexico. Based on the sea level anomaly data between 1992 and 2016, a total of 34 eddy shedding events are identified. Drawing on multiscale energy and vorticity analysis method, the eddy kinetic energy (EKE) budgets are diagnosed based on the ensemble of 34 eddy shedding events. During the stage of eddy shedding, barotropic instability (BT) dominates the energy budget. Meanwhile, energy transfers from upper layer to the deep layer by vertical pressure work (PW), which is the main source of abyssal EKE. Before eddy detachment, cyclonic eddy appears at the southeastern side of the Loop Current. Even though buoyancy forcing (BF) dominates the energy budget, BT makes considerable contribution to the generation of cyclonic eddy. Baroclinic instability (BC) shares the similar horizontal distribution with BF which accounts for 32% of the value of BC.