摘要
文中以气象卫星云图为主，分析了１９９８年７月２１～２２日由于副热带高压减弱南移，长江中下 游地区再次出现大范围暴雨过程的天气系统特征，发现：①暴雨是由 两个中-β尺度云团造成的，中-β尺度云团是发生在两个中尺度云团之间的积云区中 ，均在清晨发生，午后减弱，其生命史约为１０ ｈ左右；②云团发生在低层水汽与能量条件较 好的区域和８５０～７００ ｈＰａ低涡切变上，这里有较强的地转偏差存在，并位于６．７ μｍ水汽图 上干湿区交界的湿区一侧的环境中。
The torrential rain process occurred again in the lower and middle reaches o f Yangtze River on 21-22 July 1998, due to the fact that the subtropical high de creased and wi thdrawn southward. By using of cloud picture, an analysis of the characteristics of weather system which caused torrential rain process was made and it is shown that, fristly, the torrential rain was caused by two meso-β scale cloud c lusters which appeared in cumulus area between meso-α scale cloud clusters and it s life cycle was about 10 h;secondly, the cloud clusters occurred in the area wi th rich vapor and energy and over the 850-700 hPa shear line with strong ageostrophic wind, and w as located in the moist side of cloud system boundary.
出处
《气象学报》
CSCD
北大核心
2001年第5期625-632,共8页
Acta Meteorologica Sinica
基金
中国气象局1998年长江
嫩江流域特大暴雨成因及预报应用研究。
