HYCOM - Forecasted Global Ocean Currents – December 11, 2025 03:00 UTC (initialized December 08, 2025 12:00 UTC)

The HYCOM consortium is a multi-institutional effort sponsored by the National Ocean Partnership Program (NOPP), as part of the U. S. Global Ocean Data Assimilation Experiment (GODAE), to develop and evaluate a data-assimilative hybrid isopycnal-sigma-pressure (generalized) coordinate ocean model. Hybrid Coordinate Ocean Model (HYCOM) is the ocean model in the new Navy Earth System Prediction Capability (Navy-ESPC) (Barton et al., 2020). HYCOM has a resolution of 1/12° (the horizontal resolution is approximately 3.5km near the North Pole and 6.5km near 40°N) and 41 vertical layers. HYCOM is fully two-way coupled with the Los Alamos Sea Ice Model via the Community Ice Code (CICE) (Hunke and Lipscomb, 2008) to represent the physical processes that occur during sea ice evolution (e.g. growth, melting, and movement of sea ice, snow, and melt water). A more complete description of HYCOM physics can be found in Bleck (2002). HYCOM assimilates all available operational sources of ocean observations including satellite altimeter observations, satellite sea ice concentration, satellite and in-situ water temperature, as well as vertical T/S profiles from expendable bathythermographs, Argo floats, and moored buoys. Atmospheric forcing is obtained from the Fleet Numerical Meteorology and Oceanography Center (FNMOC) 3-hourly 0.281° Navy Global Environmental Model (NAVGEM). Wind stress calculations account for NAVGEM wind velocities, HYCOM SST, and HYCOM surface currents. Surface information is projected downward into the water column using the Improved Synthetic Ocean Profiles (ISOP) method (Helber et al., 2013). HYCOM does not include tides. HYCOM Navy-ESPC runs once daily and generates a nowcast out through a seven-day forecast. The output is typically made available within two days after the model runs via servers located at the Center for Ocean-Atmosphere Predictions Studies (COAPS) at Florida State University (FSU). Forecast fields are available at 3-hourly temporal resolution.