Diagnostic Analyses And Numerical Simulation Of Dynamical Roles Of Atmosphere Over The Tropical Pacific On Ocean And SSTA Forecast Experiment

Based on NCEP/NCAR reanalysis SST and wind data set and FSU wind stress data, the dynamical roles of Atmosphere over the Tropical Pacific on ocean are diagnostically analyzed. By using a dynamical ocean model over tropical Pacific, the importance of dynamical roles of different areas atmosphere on ocean is studied. In the part III of this work, a intermediate coupled model (ICM) is employed to study SSTA forecast experiment. Diagnostic results show that the westerly wind stress anomaly and convergent meridional wind stress anomaly over the tropical Pacific correspond to the every El Nino, and the easterly anomaly and divergent meridional wind stress anomaly correspond to the vanishing of El Nino. The faction and degree of dynamical roles of atmosphere on ocean directly determine the pattern of oceanic anomaly. Although sea surface temperature anomaly center generally occur in the equatorial eastern Pacific, key zone of pre-wind stress anomaly forcing signal related to SSTA lies in the central western Pacific. Both diagnostic and numerical analyses results show this idea. Forecast experiments results show that forecast ability of ICM may be improved while the large scale relationship between ocean and atmosphere is given clearly, and the SSTA pattern of forecasting is very correct. Base on this study, the numerical forecast of 2000's tropical Pacific SSTA has been done. It shows that it is weak La Nina event in 2000. Singular value decomposition (SVD) is used in constructing a atmosphere model of coupled model. This kind model is proved that it has ability to forecast El Nino event, especially, degree and site and occurring time of El Nino in forecast experiment agree with the observation results.