ENSO与北半球冬季大气环流异常年代际关系的数值模拟

利用NCAR/CCM3大气环流模式,模拟不同海温背景场强迫下,北半球冬季大气环流对ENSO事件的响应。结果表明,模式能够模拟出不同海温背景场下,北半球冬季大气环流对ENSO事件的不同响应,模拟结果与诊断结果基本一致。在20世纪70年代末之后的平均海温背景场强迫下,El Nio对阿留申低压的加强作用比70年代末之前更明显,而ENSO暖位相对蒙古高压的作用则由70年代末之前的轻微减弱变为明显加强。虽然70年代末以后ENSO事件的强度比70年代末之前有所增大,但ENSO对东亚大槽和东亚冬季风的减弱作用反而不再那么明显;同时在高空风场中,由ENSO激发出的PNA型异常环流在70年代末以后明显加强。

Numerical simulation of interdecadal relationship between ENSO and Northern winter atmospheric circulation anomalies

Different responses of Northern winter atmospheric circulation to ENSO events are simulated under different surface sea temperature(SST) forcings using NCAR/CCM3 model.Comparison between simulated results and diagnostic results indicates that the model can simulate the response of Northern winter atmospheric circulation to ENSO events under different SST forcings.The simulated results are agree with the diagnostic results.Under SST forcing after the late 1970s,the strengthening action of El Niño events on Aleutian low is more obvious.Mongolian high is slightly weakened by El Niño events before the late 1970s,but it is markedly strengthened after the late 1970s.After the late 1970s,the strength of ENSO events becomes larger,but the abated effect of ENSO on East Asian trough and East Asian winter monsoon is not clear,and PNA pattern is obviously strengthened by El Niño events.