摘要
华北回流天气是预报中的难题,尤其是对其产生降水的开始和结束时间和华北回流的性质研究不多。作者使用NCEP再分析资料、实时观测资料和中尺度模式MM5,对一次回流暴雪过程进行了诊断分析和数值试验。通过分析和试验得出了一些有意义的结果:回流降水的开始和结束与高低层的风向有关,中高层的西南气流与低层偏东气流叠加时降水开始,两者之一消失降水结束;低层经渤海回流到华北地区的气团是干冷的;回流降水的水汽伴随中层的西南气流来自南方地区。这在实际业务预报中具有很好的指示意义。
It is difficult to forecast the return-flow weather which occurred over North China. In order to reveal the mechanism of return-flow weather, such as the character of return-flow, a heavy snow of return-flow weather which occurred over North China was diagnosed and investigated by using NCEP data and the Pennsylvania State University-NCAR Fifth-Generation Mesoscale Model （MM5）, version 3. The results show that the start and end time of precipitation was closely related to the wind direction, including the upper warm and humid air and lower cold air. The lower layer air from Northeast Plain through Bohai Sea was drier and colder than the upper air from southwest. The moisture of return-flow weather mainly came from southwest with southwestern flow.
出处
《气象》
CSCD
北大核心
2007年第9期25-32,共8页
Meteorological Monthly
基金
中国气象局气象灾害天气国家重点实验室开放课题CMATG2005Y06资助
关键词
回流
暴雪
数值试验
return-flow events heavy snow numerical experiments
