准两年振荡及其对东亚大气环流和气候的影响

通过多年资料分析,本文研究了平流层准两年振荡(QBO)的演变特征及其对东亚及西太平洋地区大气环流和气候变化的影响.结果表明,平流层QBO的演变特征是:东风向西风转换最早出现在印度洋赤道地区;西风向东风转换最早出现在美洲和西太平洋赤道地区.中国东部降水量、气温以及西太平洋副高和东亚急流都有准两年周期变化,并同平流层QBO有密切关系;平流层QBO对西太平洋台风活动也有一定影响,QBO的西风位相期西太平洋台风偏少.另外,ENSO对于平流层QBO有明显影响,一般在ENSO发生之后,QBO的西风位相期持续时间缩短.

QBO and Its Influence on the General Atmospheric Circulation and the Climate in East Asia

In this paper, the evolution properties of the stratospheric QBO and its influence on the general atmospheric circulation and the climate in East Asia/the western Pacific are studied by analyzing data of many years. Results show that the transition from the easterly to the westerly originates in the equatorial Indian Ocean, and from the westerly to the easterly in tropical America and the equatorial western Pacific. There are quasi-biennial variations in the precipitation, the temperature in East China/the subtropical high over the western Pacific and the Jet in East Asia. They are closely related to the stratospheric QBO. The stratospheric QBO also affects the typhoon activity over the western Pacific. The number of the typhoon over the western Pacific is smaller during the period of the QBO's westerly phase. In addition, ENSO obviously affects the stratospheric QBO. Generally, after ENSO's occurrence, the continued length of the QBO's westerly phase is shortened.