【摘要】 利用NCEP/NCAR再分析资料和NCAR海温资料及中国测站地温资料 ,对ENSO循环不同阶段东亚夏季风强弱变化进行了分析。并从此期间的海陆热力差异和季风低压变化来探讨海温异常对东亚夏季风的影响 ,结果表明 :东亚夏季风指数有明显的年际变化和年代际变化 ,且与赤道东太平洋SST有较好的负相关关系 ,其中又以与三个月前的海温变化关系最好。在Nino1+2区为冷、暖水之后的三个月中 ,冷水期对应的东亚夏季风指数大于暖水期对应的东亚夏季风指数 ,东亚夏季风比暖水期强。赤道东太平洋SST变化期间亚洲大陆的地面温度和地面气压也有明显变化 ,这是引起ENSO不同阶段东亚夏季风变化的主要原因。更多还原

【Abstract】 The variation of East Asia summer monsoon in different phases of ENSO cycle has been analyzed by using reanalysis grid data from NCEP/NCAR, sea surface temperature data from NCAR and ground surface temperature data from observational station of China. The effect of abnormal SST on East Asia summer monsoon has been discussed through the variation of land-sea thermal difference and monsoon low pressure. The results show that there are obvious yearly and decadal changes in East Asia summer monsoon index, and there is also good negative correlation between the index and SST in east equatorial Pacific. The East Asia summer monsoon index is bigger in the period after three months of cool Nino1+2 SST than that after the warm Nino1+2 SST. There are also obvious variations of land surface temperature and sea level pressure in Asia continent when east equatorial Pacific SST changes. In the summer, after three months of warm Nino1+2 SST, the land surface temperature is lower in the area north of Yangtze River, the sea level pressure in Asian continent is higher, as well as the summer monsoon depression in Asia is weakened. It is contrary in the case after cool Nino1+2 SST. That means, the oscillation of sea level pressure induced by east equatorial Pacific SST anomaly appears not only in the oceans, but also in the continents. It should be the main reason that leads to the variation of East Asia summer monsoon in different periods of ENSO cycle.更多还原