An Assessment of Forecasting Skill for GOFS 3.1 and Three Configurations of RNCOM in the Vicinity of Hawaii

Fleet Numerical Meteorology and Oceanography Center (FNMOC) runs operational atmosphere and ocean circulation models, forecasting weather and ocean conditions out 72-168 hours on coastal, regional and global scales. FNMOC’s operational global and regional atmospheric models are the NAVal Global Environment Model (NAVGEM) and the Coupled Ocean / Atmosphere Mesoscale Prediction System (COAMPS), respectively. FNMOC’s operational global and regional ocean circulation models are the Global Ocean Forecast System (GOFS 3.1) and the Regional Navy Coastal Ocean Model (RNCOM), respectively. GOFS 3.1 is a configuration of the Hybrid Coordinate Ocean Model (HYCOM) coupled with the Community Ice CodE (CICE) ice model. A comparison of forecasting skill will be made between four models for the Hawaii domain for the time period of mid-May to mid-August 2018: 1) GOFS 3.1 with a horizontal resolution of 9 km, 41 vertical layers, and atmospherically forced by NAVGEM; 2) the operational RNCOM with a horizontal resolution of 3.7 km, 41 vertical layers, and atmospherically forced by the Hawaii COAMPS; 3) an experimental RNCOM run with a horizontal resolution of 2 km, 75 vertical layers, and atmospherically forced by the Hawaii COAMPS; and 4) an experimental RNCOM run with a horizontal resolution of 2 km, 75 vertical layers, and atmospherically forced by NAVGEM. Model output will be compared to in situ and satellite observations in order to determine the impact of model resolution and atmospheric forcing differences on model accuracy. Feature strength and placement, mixed layer and thermocline characterization, diurnal cycle representation and other parameters will be assessed from hydrographic profiles, drifting buoys, and altimetry.