Simulation of the North Atlantic circulation at 1/50°

Horizontal resolution of an ocean general circulation model and thus the model's capability of resolving eddies play an important role in model's representation of large--‐scale circulation. Here we describe the impact of resolution on the representation of the Gulf Stream and the North Atlantic Current in a series of simulation of the North Atlantic (1/12°,1/25°, and 1/50°) using the Hybrid Coordinate Ocean Model (HYCOM). These simulations are configured with the same bottom bathymetry, vertical layer structure, and surface forcing, with the horizontal resolution being the only difference. The results show that the Gulf Stream extension is significantly better represented at higher resolution, especially the narrow southern recirculation of the Gulf Stream east of 65°W and the transition from the Gulf Stream to the North Atlantic Current. The results highlight the role of eddies, both mescoscale and submesoscale, in setting up the energetic western boundary circulation.