A coupled numerical model to investigate the air-sea interaction at the coastal upwelling area of Cabo Frio, Brazil

摘要

This work investigates the capability of an oceanic numerical model dynamic and thermodynamically coupled to a three-dimensional mesoscale atmospheric numerical model to simulate the basic features of the air-sea interaction in the coastal upwelling area of Cabo Frio (RJ, Brazil). The upwelling/downwelling regime is an important feature in the oceanic circulation of Cabo Frio and determines the sustainability of local ecosystems. This regime is predominantly driven by the atmospheric circulation and is well documented, being suitable to be used as test reference for atmospheric and oceanic coupled and uncoupled models. The oceanic boundary conditions, coastline shape and coupling effect have been tested. The uncoupled oceanic model forced by a NE (SW) wind field generates a realistic upwelling (downwelling) phenomenon regardless of the proximity of the lateral boundary and how realistic is the shape of the coastline. The atmospheric-oceanic coupled model generates an upwelling location and intensity similar to the uncoupled simulation, but the upwelling is gradually enhanced by the sea-breeze circulation. It also generates vertical profiles of mixing ratio that compare better to the observations than the uncoupled simulation and air potential temperature and wind vertical profiles that represent particular features of the atmospheric circulation at Cabo Frio.