1998年6月下旬长江中下游强降水过程成因分析
CAUSALITY ANALYSIS OF A HEAVY RAIN PROCESS OVER MIDDLE AND LOWER REACHES OF CHANGJIANG RIVER IN JUNE 1998
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摘要: 利用国家气象中心的有限区域预报模式,对1998年6月下旬发生的一次强降水过程进行了数值试验,并通过对风场、水汽场、垂直速度场等变量的诊断分析,对降水过程的成因进行了初步探讨。分析结果显示,北方南下的干空气与西南暖湿气流在长江中下游地区形成的切变和西南低空急流是造成这次大暴雨的主要天气尺度系统,而沿切变线移动的中尺度系统对降水的增强起了重要作用。Abstract: A numerical experiment on a heavy rain process occurred in the last dekad of June in 1998 is conducted by means of the limited area prediction model of the National Meteorological Center. The formation causes of the process are discussed through analyzing the winds, water vapor, vertical velocity and other elements. The results show that the main synoptic scale weather systems causing the heavy rain are the Southwest low-level jet and a shear line between dry air from north and warm and moist air from /southwest in the middle and lower reaches of the Changjiang River. The mesoscale weather systems moving along the shear line play a very important role in precipitation reinforcement
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Key words:
- Heavy rain;
- Numerical experiment;
- Low-level jet;
- Shear line
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[1] 闫之辉,郭肖容,赵俊英,等.一个载水预报模式的业务预报应用试验.应用气象学报,1999,10(4):453-461. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=19990487&flag=1 [2] 国家气象中心,国家气候中心.1998中国大洪水与天气预报.北京:气象出版社,1999.65-68.