Studies of island regions using observations and air-sea coupled modeling

Accurate forecasting of coastal oceanic and atmospheric circulation is particularly challenging in island regions due to a number of factors. Many islands possess steep terrain and varying microclimates. We have undertaken a series of studies from complex archipelagos (Philippines) to single island settings (Madeira) in order to probe how the ocean interacts with topographically-enhanced atmospheric flows. We apply a nested data-assimilating coupled air-sea model (COAMPS) at high resolution (1-3 km) and utilize observations to evaluate and improve model performance. The Madeira simulations examine air-sea interaction in the warm wake region of a single island. Supported by field data (including satellite, atmospheric soundings, meteorological stations and in situ ocean measurements) we document the evolution of the oceanic and atmospheric boundary layers during several events in the summertime, when lee vortex shedding in the atmosphere is most pronounced. We also investigate how downslope winds impact air/sea fluxes, and explore the generating mechanisms of ocean eddies.