Simple Coupled Ocean-atmosphere Model Of The Nonlinear Term Impact Of The Enso Cycle

In this paper, nonlinear extension has been operated in linear air-sea model included in ZC model. The influence of period, phase and amplitude of ENSO cycles is investigated when zonal or meridional factors or both of them are considered in governing equations for the air-sea. The sensitivity of ENSO cycles to nonlinear factors in governing equations for the sea is discussed too, the conclusions are below:(1) The influence of adding zonal or meridional ones of nonlinear factors in governing equations for the air upon the interseasonal variation of ENSO is very little, however, the interseasonal variation can be weakened after adding zonal and meridional nonlinear factors at the same time. As far as the interannual change of ENSO is concerned, these three kinds of nonlinear ones all can lead the maximal period of the local wavelet power spectrum about the area-averaged SST anomalies at Nino3 area change. As for the interdecadal change of ENSO, the changes of nonlinear factors in governing equations for the air can make ENSO cycles change. From the analysis on the sensitivity of ENSO cycles to nonlinear factors, ENSO cycles have response to zonal nonlinear factors is more obviously.(2) The influence of adding zonal or meridional ones of nonlinear factors in governing equations for the sea upon the interseasonal variation of ENSO is very little, however, the interseasonal variation can make it change after adding zonal and meridional nonlinear factors at the same time. As far as the interannual change of ENSO is concerned, these three kinds of nonlinear ones all can lead the maximal period of the local wavelet power spectrum about the area-averaged SST anomalies at Nino3 area change. As for the interdecadal change of ENSO, the changes of nonlinear factors in governing equations for the air can make ENSO cycles change.(3) Adding zonal nonlinear factors in governing equations for the air and sea make seasonal change strengthen, and seasonal change will weaken after adding meridional or zonal and meridional ones at the same time. As far as the interannual change of ENSO is concerned, The 3~5 year periods of ENSO cycles are more obviously after adding zonal ones in governingequations for the air and sea, and the different period vacillations at the same stage of ENSO cycles are more obviously after adding meridional ones in governing equations for the air and sea. As for the interdecadal change of ENSO, the changes of nonlinear factors in governing equations for the air don't make ENSO cycles change obviously. But it is sensible of phase and amplitude in ENSO cycles, zonal and meridional ones can make phase and amplitude change greatly. And it can be seen that it is sensible of phase and amplitude in ENSO cycles to little nonlinear factors in governing equations for the air and sea, and it is more sensible to zonal.