Typhoon and ENSO simulation using a high-resolution coupled GCM

The relationship between the character of tropical storm (TS) activity in the northwestern equatorial Pacific (NWEP) and the El Niño-Southern Oscillation (ENSO) is investigated from the viewpoint of how TS behavior varies interannually. A high-resolution coupled general circulation model (CGCM) capable of simultaneously reproducing both TSs and ENSOs has been developed to study the role of air-sea interaction in linking TS activity with ENSO. Analysis of 15 years simulation and observations shows that TS frequency decreases slightly off the Philippine Islands (120°E-150°E, 5°N-20°N) and that the location of their generation shifts toward the east during El Niño years. This results in inactive convection in the NWEP during El Niño years due to an increase in sea level pressure over ocean areas.