海洋对ENSO和其他时间尺度上风应力振荡的响应

利用带通滤波方法，将FSU风应力资料分离成ENSO时间尺度上的分量及其剩余部分，将这两部分分别作用于模式海洋（2层热带太平洋区域模式），研究海洋对不同时间尺度大气变化的响应。结果表明：尺管ENSO时间尺度上的风应力分量只占风应力扰动总方差的30％左右，它却能激发出全部异常风应力强迫海洋时所产生的El Nino/La Nina现象和十分相近的SSTA变化周期与振幅。而其余占总异常风应力方差60％以上的部分强迫海洋仅能产生振幅较小的海表温度异常，在非ENSO和ENSO时间尺度上的风应力强迫下，海洋中可产生相近振幅的Kelvin波，但SSTA振幅却存在显著差别，表明海洋对大气扰动信号的频率非常敏感，这里从理论上对该现象作了解释和说明。

Response of the Tropical Pacific to the Windstress Components on ENSO and Non-ENSO Time Scales

A two-layer tropical Pacific ocean model and the FSU pseudo windstress are employed to investigate the response of the model ocean to the anomalous windstress on different time scales.The timeseries of windstress is decomposed into an ENSO-time-scale component and the residual part,by use of a band-pass filter.It is found that the ENSO cycles are successfully generated with the forcing of windstress anomalies on ENSO time scale.The SSTA has almost the same period and phase as compared to those simulated with the forcing of the total windstress although the anomalous windstress on ENSO time scale only explains 30% of total variance of total windstress anomalies.The rest part that explains approximately 60% of total variance of windstress anomalies drives ocean to produce a variation with much smaller amplitude in sea surface temperature.The Kelvin waves can be excited in the first layer of the model-ocean by both the ENSO time scale wind-stress component and the residual part (non-ENSO) on other time-scales.A theoretical explanation is given as the reason why the intensities of sea surface temperature anomalies are much different although the intensities of Kelvin modes in the two experiments are very comparable.