Abstract:

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.

Suggested Citation:

Patrick Hogan, Angelique Haza, Tamay Özgökmen. 2018. HYCOM 1 km resolution surface fields of the Gulf of Mexico for January-March 2010. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7BC3WJC

Publications:

Haza, A. C., Özgökmen, T. M., & Hogan, P. (2016). Impact of submesoscales on surface material distribution in a gulf of Mexico mesoscale eddy. Ocean Modelling, 107, 28–47. doi:10.1016/j.ocemod.2016.10.002

Grossi, M. D., Kubat, M., & Özgökmen, T. M. (2020). Predicting particle trajectories in oceanic flows using artificial neural networks. Ocean Modelling, 101707. doi:10.1016/j.ocemod.2020.101707

Purpose:

The model outputs are used to analyze the mesoscale-submesoscale interaction in the context of Lagrangian transport in (see Impact of Submesoscales on Surface Material Distribution in a Gulf of Mexico Mesoscale Eddy, Haza et al., 2016). The requirements of this HYCOM simulation are that: (a) the model has enough numerical resolution to capture some of the submesoscale mixed layer instabilities, and (b) the flow field contains one of the so-called ``Star Eddies" (Ozgokmen et al., 2012) so that the influence of submesoscales on surface material fluxes across mesoscale material boundaries in elliptic coherent features can be assessed.

Data Parameters and Units:

MT = days since 1900-12-31 00:00:00 Latitude in degrees North Longitude in degrees East Date (%Y%m%d.%f) Mixed layer thickness (m) Sea surface salinity (psu) Sea surface height (m) Eastward sea water velocity (u, m/s) Northward sea water velocity (v, m/s) Sea surface temperature (sst, deg C) The output data sets consist of atmospheric forcing in MKS units. Heat flux is positive into the ocean. The output files consist of the COADS fields interpolated to the HYCOM grid in HYCOM 2.1 array “.a” and header “.b” format.

Provenance and Historical References:

Bleck, R.: An oceanic general circulation model framed in hybrid isopycnic-Cartesian coordinates, Ocean Modeling, 4, 55-88, doi: 10.1016/S1463-5003(01)00012-9, 2002.

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