Hurricane Gilbert (1988) was one of the strongest storms in the Atlantic in recent history. During its passage in the western Gulf of Mexico, a warm core eddy was positioned at a distance of about 4 R<sub>max</sub> (radius of maximum winds, 60 km) from the storm-track. High resolution observations were acquired by deploying Airborne eXpendable Current Profilers (AXCPs) and Airborne eXpendable BathyThermographs (AXBTs) before, during and one and three days following the storm passage. These data were objectively analyzed
and are used to investigate the effect of warm core eddy on the upper ocean heat, mass and momentum balance during and subsequent to the storm passage. Relative magnitudes of advection and vertical mixing in the upper ocean are estimated using a diagnostic three-dimensional mixed layer model where the turbulent fluxes at the surface and mixed layer base are specified by bulk formulations. Results indicate that entrainment at the base of the mixed layer contributes about 80% to the observed Sea Surface Temperature decrease close to storm-track. However, in the eddy region, strong horizontal velocities associated with the warm core eddy significantly modulate the mixed layer heat and mass balance.
These observational data are used to initialize the Miami Isopycnic
Coordinate Ocean Model (MICOM) in the Gulf of Mexico. This model uses
explicit mixed layer physics with different entrainment mixing mechanisms to investigate the upper ocean response including the heat, mass and momentum balances in the vicinity of the mesoscale features. The important question is how the interaction between oceanic mesoscale features and storm-induced response modifies the upper ocean heat content and SST leading to rapid storm intensification. In addition, hurricane Gilbert was going through eye wall replacement in the western Gulf of Mexico, that resulted in a very broad wind field, with dual wind maxima. By using realistic wind fields, the numerical simulations will address the effect of dual wind maxima on the
ocean response and the modulation of air-sea fluxes.