西太平洋副高活动与平流层QBO关系的研究

资料分析表明，西太平洋副高活动有准两年振荡特征，副高的相对强度和副高脊线的纬度位置都清楚地表现出这种振荡。而且分析还表明，平流层低层纬向风的垂直切变同西太平洋副高活动有关，东（西）风切变对应着脊线位置偏北的较强（弱）副高形势。平流层低层东（西）垂直切变在赤道对流层上部所引起的异常上升（下沉）运动，导致Hadley环流的异常加强（减弱）可能是平流层QBO影响西太平洋副高准两年振荡的重要机制。用IAP-GCM所作的数值模拟试验得到了同观测资料分析相一致的结果。

Study on Subtropical High Activity over the Western Pacific and QBO in the Stratosphere

Based on the data analyses, the quasi-biennial oscillation feature of subtropical high over the western Pacific is studied. This oscillation is very clear in both relative intensity and the ridge-latitude location of subtropical high. The analyses still show that the vertical shear of zonal wind in the lower stratosphere is related to subtropical high activity over the western Pacific, easterly (westerly) shear corresponds to stronger (weaker) subtropical high and the ridge locating to north (south) side. The ascending (sinking) motion in the upper troposphere over the equator caused by the easterly (westerly) shear in lower stratosphere will rise (weaken) the Hadley cell, and this is a possible important mechanism in relation to the influence of QBO on the subtropical high activity over the western Pacific. The simulations in IAP-GCM are also completed in this study and the results are similar with that in the observation data analyses.