Monsoon surges trigger oceanic eddy formation and propagation in the lee of the Philippine Islands

Two winter monsoon surge events (northerly and easterly) of January 2005 are captured in a one-way coupled atmosphere (8 km resolution) and ocean (3 km resolution) simulation of the Philippines region. Intensified wind jets and wakes in the lee of Mindoro and Luzon Islands induce the generation and migration of a pair of counter-rotating oceanic eddies in the model, with propagation direction related to the orientation of the winds during each of the surges. Features shared by the eddies include size (100–200 km), depth (~300 m) and propagation speed (0.1–0.15 m s-1 for cyclones). Mean wintertime model wind stress positive (negative) curl coincides with the climatological cyclone (anticyclone) distribution from a prior 8-year altimetry-based census of eddies in the southeast quadrant of the South China Sea during the winter monsoon. Moreover, the simulation results agree with contemporaneous satellite and historical in situ data characterizing regional oceanic eddy and atmospheric surface jet properties.