Effects of Air-Sea Interactions on the Decay of Lagrangian Coherent Vortices

Coherent eddies can be long lived and carry water masses across ocean basins. Although their formation processes were extensively studied, the processes responsible for their decay and the mixing of their tracers remain poorly understood. Recent studies pointed out the effect of air-sea interactions in the form of wind stress work and Ekman pumping, due to current feedback on wind stress, on the decay of their energy. However, these studies were based on Eulerian eddy tracking methods that may sometimes be unreliable to perform thorough energy and heat budgets. Here, we take advantage of these previously validated empirical methods to reconstruct the three-dimensional temperature and salinity structure of warm-core rings, along with Lagrangian objective eddy framing methods to study the life cycle of energy, heat an salt of Loop Current rings in the Gulf of Mexico. We show that, although kinetic energy is well conserved, and wind stress work seems to have little effect on Loop Current rings, Ekman pumping buoyancy fluxes are a major source of available potential energy loss, and Lagrangian Coherent Loop Current Rings decay at an exponential rate.