| Using 925hPa NCEP/NCAR reanalysis wind data to replace FSU wind data improves initialization impact wind field of Zebiak-Cane ocean-atmosphere coupled model (hereafter referred to as ZC coupled model). Subsequently, 1997/1998 El Nino is analyzed on the base of simulated and observed data, and a new possible mechanism for the evolution of the 1997/1998 El Nino is advanced. Then genesis mechanism for ENSO is perfected further. At last, the parameterization scheme for latent heat calculation included in atmosphere model of ZC coupled model with revised initialization impact wind is modified. The results are as follows:(1) The 925hPa NECP/NCAR reanalysis wind stress anomaly (hereafter referred to as NECP wind stress anomaly) is more fit to observed SSTA than the FSU wind stress anomaly both in 1980s and in 1990s. Employing the former to take the place of the latter as the initialization impact wind not only make the ZC ocean model have a better skill, especially in 1990s but also improve the forecast ability of the ZC coupled model, which can succeed in predicting 1997/1998 El Nino before 6 to 8 months. The ZC coupled model with the revised initialization impact wind (hereafter referred to as ZCW coupled model) is not clearly confronted with "spring forecast barrier" but has limited capability to forecast cold event.(2) The thermodynamic analysis of 1997/1998 El Nino shows that in NINO4 the contribution of the zonal and the meridional advection to the SSTA increase are equivalent and both bigger than that of the vertical upwelling flow; in NINO3 the contribution of the meridional advection to SSTA increase is the most and the counterparts of the zonal advection and vertical upwelling flow are equivalent; in NINO 1+2 it is still the most that the contribution of the meridional advection to SSTA increase, and the counterpart of the zonal advection is less than that of the vertical upwelling flow. In a whole, the contribution of the meridional advection to the SSTA increase is the most and the counterparts of the zonal advection and upwelling flow are equivalent. From NINO4 to NINO 1+2 the contribution of the zonal advection to SSTA increase decreases approximately in such a way that the counterparts of the meridional advection and vertical upwelling flow increase. In the whole process the thermodynamic damping suppresses basically the SSTA increase, and the suppression becomes strong gradually.(3) During the 1997/1998 El Nino we find western Pacific warm pool (WPWP) SST variation, abnormal west wind, eastern Pacific warm pool (EPWP) SST variation and abnormal north wind are associated with the NINO3 index change. Based on the EPWP and WPWP in conjunction with abnormal north and west wind, a new possibleiiimechanism is provided for the evolution of the 1997/1998 El Nino. To be specific, the warm Kelvin wave propagating to east excited by the abnormal west wind can suppress the cold upwelling flow in the eastern Pacific, which, in turn, is favorable to the eastern Pacific SST increase; abnormal west wind can make the warm water of the WPWP east edge extend to east, which is conductive directly to eastern Pacific SST increase; the abnormal west wind propagating to east can make the sea surface warm water near two equatorial laterals converge to the equator by Ekman drifting, which, in rum, strengthens the downwelling flow near the equator, leading to eastern Pacific SST increase. Almost meanwhile, the north wind anomaly brings EPWP warm water to equatorial vicinity by producing north ocean flow, which causes directly NINO3 SST increase. As a result, such factors favoring to SST increase give rise to 1997/1998 El Nino quick occurrence and abnormal strength. Furthermore, the origins of abnormal west and north wind during the 1997/1998 El Nino are explored primarily.(4) The EPWP climatologic SST has a clear intraseasonal variability, which is very similar to El Nino growth process, i.e., occurring in spring, developing in summer, maturing in autumn and decaying in winter. Based on the analysis of meri...
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