High-resolution air-sea modeling of the Philippines winter monsoon

Winter monsoon conditions during February 2005 over the Philippines are simulated using COAMPS (triply nested down to 8 km resolution) forcing a regional NCOM ocean model (3 km resolution). The high-resolution COAMPS grid produces intense wind jets associated with the mountain orography and gaps between islands. The structure of the simulated features agrees with contemporaneous QuikSCAT-derived wind stresses. The strong curl of these wind jets leads to a double gyre ocean circulation pattern near Mindoro Straits. Sensitivity simulations utilizing either global NCOM or global HYCOM (both data-assimilating) for initial and boundary conditions produce the wind-driven ocean gyre structures although the general background ocean circulation is very different between the two simulations. A two-way coupled modeling test is also being run for the region.