HYCOM 1 km resolution surface fields of the Gulf of Mexico for January-March 2010

The HYbrid Coordinate Ocean Model (HYCOM) is configured for the entire Gulf of Mexico. HYCOM uses isopycnal coordinates in the deep stratified ocean, pressure coordinates in unstratified regions including the mixed layer, and terrain-following coordinates in shallow coastal regions. The simulation has 20 layers in the vertical and 1/100 degree horizontal resolution. The flow is forced by six-hourly Navy Operational Global Atmospheric Prediction System (NOGAPS) surface winds and heat fluxes. Cyclic boundary conditions south of the Yucatan Channel and in the Florida Straits are provided by a synoptically-forced 1/12 degree Atlantic HYCOM configured for much of the Atlantic Ocean, from 30S to 70N. The results from this larger domain simulation are obtained for years 1999-2002 and binned into monthly values to create a perpetual forcing and boundary conditions for the Gulf of Mexico inner domain. Rivers are represented by point sources forced towards monthly climatological freshwater inflows. Further details of the model configuration can be found in Prasad and Hogan (2007). The k-Profile parameterization (KPP; Large et al., 1994) is used to invoke vertical mixing. The model was run over 2010 and demonstrates dynamically-realistic behavior. In particular, the simulation generates a number of cyclones that tend to orbit around the anticyclonic Loop Current Eddies. The cyclones and anticyclones seldom cross the shelf break front in the northern Gulf of Mexico, although filaments associated with baroclinically-unstable eddies do generate cross-shelf exchange and interact with largely barotropic flows that tend to follow the shelf break front. Loop Current eddy shedding and wind-driven upwelling near the Yucatan Peninsula seem to be generally consistent with observations (Morey et al., 2003; Walker et al., 2005; Sturges et al., 2005), although they occur non-contemporaneously because of lack of data assimilation.