This paper mainly focuses on how the coupled ocean-atmosphere model responses to external forcing and proposes two numerical experiment schemes: one is called the attachment scheme and the other is called the substition scheme.

Using the model experiment results from modified NCAR CCM3,modified NCAR CAM2 and NCEP GFS models,the influences of external forcing of SST and solar radiation(SR) on the tropical intraseasonal oscillation(TIO) are discussed.

On the basis of former studies about ENSO mechanism and how external forcing affects ENSO, we brought forward two important questions as follows: which region is the key region of ocean-atmosphere interaction in the tropical Pacific Ocean and how does the interseasonal oscillation (MJO) and monsoon influence ENSO cycle? This paper st.

Furthermore,the causes of drought were analyzed and the outer factors such as ENSO and solar activities influencing on the drought scale, extent and responding time were studied also by using cross spectrum.

On the basis of sub-linear delay differential system, the forced sub-linear variable delay differential system under linear impulsive perturbations was discussed,and asymptotic property of solution for this system was studied.

A sufficient condition under which all solutions of a type of forced neutral nonlinear retarded difference equation converges asymptotically to zero is presented.

Some sufficient conditions are obtained for the asymptotic behavior of solutions of forced nonlinear delay difference equations,and the corrsponding results in Graef and Qianare improved and generalized.