NUMERICAL MODELING STUDY OF EFFECTS OF EASTERN PACIFIC WARM POOL ON ENSO

In this study, sensitivity experiments were conducted with the Zebiak-Cane ocean-atmosphere coupled model forced by the wind stress anomaly from the U.S. National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data to study the impacts of eastern Pacific warm pool on the formation and development of ENSO events. The effects of climatological mean sea surface temperature of the warm pool on forecast skill during the ENSO events of 1982–C1999 are more considerable that those of climatological mean meridional winds and ocean currents. The forecast skill for the 1997/1998 El Niño event is characterized by sensitivity to climatological mean sea surface temperature and anomalies of northerly winds and currents. The forecast skill is found insensitive to climatological mean northerly meridional winds and currents.