Oceanic Submesoscale Eddies within High-Resolution Model Simulations

Upper ocean variability is dominated by processes and features at a variety of scales, including both mesoscale (ranging from 10-300 km) and submesoscale (ranging from 1 to 10 km) motions. The focus of this study is submesoscale eddies within the upper ocean. To examine and understand small-scale motions in ocean model simulations, the atmospheric forcing, i.e. momentum and heat fluxes at the air-sea interface, must also be considered. In this study, we use the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) to produce 3km horizontal resolution atmospheric forcing over the western Pacific. The Navy Coastal Ocean Model (NCOM) is then used to produce ocean model simulations with 375 m horizontal resolution and vertical resolution varying from 0.5 m at the ocean surface to 250 m at depth. The high horizontal resolution within the atmosphere is necessary to provide small scale forcing to the ocean. Similarly, the high horizontal and vertical resolutions within the ocean are necessary to fully capture the relevant motions related to the submesoscale processes. Within this study, we are able to identify and track oceanic submesoscale eddies separately from other submesoscale processes, such as fronts and filaments. By identifying the submesoscale eddies within the upper ocean, we are able to evaluate the atmospheric conditions at the air-sea interface in which they form and mature, and determine favorable vs unfavorable surface conditions. Additionally, the upper ocean dynamics are evaluated to determine the impacts oceanic submesoscale eddies have on their surrounding environment.