batch_auto_20260713 202607131256465730 BOEM ESP geoESPIS ESPIS@boem.gov Bureau of Ocean Energy Management High Resolution Modeling of the Gulf of Mexico College of Arts and Sciences, Center for Ocean-Atmosphere Prediction Studies Florida State University The Bureau of Ocean Energy Management (BOEM) needs better and more accurate information on ocean currents and eddy activities in the Gulf of America (Gulf; formerly the Gulf of Mexico) (BOEM, 2014; Chassignet and Srinivasan, 2015). The overall objective of this study is to improve our understanding of the multi-scale variations (spatially and in time) of the physical processes in the Gulf. The specific objectives are to 1) increase the horizontal resolution of the current Gulf HYbrid Coordinate Ocean Model (HYCOM) configuration from 1/25° (~4-km) to 1/100° (~1-km) resolution; 2) validate the simulation and quantify the impact of the submesoscale; and 3) perform a 20-year (2001–2020) reanalysis. Accurate representation and/or understanding of the ocean dynamics is crucial for simulating of the oil trajectories, since location of mesoscale and submesoscale features largely determines local surface oil transport. A detailed model-to-observations comparison shows, for the most energetic events, there is a good agreement between model and observations. For subsurface flow events, the match between model and observations is not as good, but it is better in the 1-km resolution configuration. In the 1-km experiment, smaller scale Lagrangian Coherent Structures (LCSs) emerge as noise-like filaments that suggest a larger turbulent mixing component than in the 4-km experiment. Oil trajectories are clearly impacted by the horizontal resolution increase, with more oil particles reaching the coastlines of the northern Gulf, if advected using surface velocities from the 1-km simulation. 490000 U.S. Department of the Interior, Bureau of Ocean Energy Management, Environmental Studies Program https://doi.org/10.13039/100012475 M20AC10020 10.67297/9A1E8C https://boem.gov/awardpages/100364