摘要
利用FNL客观分析资料,常规探空、地面观测以及卫星云图资料,结合滤波和物理量诊断方法对2008年7月31日辽宁一次大暴雨过程进行分析.结果表明:在高空500 hPa冷槽缓慢南下与西太平洋副热带高压北抬的有利大尺度环流场形势下,中尺度辐合系统在冷暖锋的暖区内形成发展是造成此次暴雨过程的直接原因,利用滤波方法可以很好地分离出中尺度系统.此次暴雨过程主要分为两个阶段,第一阶段降水过程基本发生在暖区内,而并非锋面上,第二阶段的雨带呈现东北—西南走向.暴雨发生发展过程中,大尺度环流和中尺度环流系统都对水汽的输送起促进作用,到暴雨消散期则都不利于水汽的供应.这也表示暴雨发展期间,中尺度环流系统对水汽输送有着重要的作用.
A heavy rainstorm in Liaoning on July 31, 2008 was analyzed with 6-hourly FNL data of 1°× 1°, sounding data, surface observations, satellite images, associated filtering method and physical diagnosis, and the main results are： a synoptic analysis indicated that the cold trough at 500 hPa moved southward slowly and the western Pacific subtropical high jumped northward. Mesoscale systems forming in the warm sector of fronts directly contributed to the development of rainstorm and they could be well separated from the background field by the filtering method. There were two processes during the rainstorm： the first occurred in the warm sector rather than on the front surface and the rain belt in the second process moved northeastward. In the development period of the rainstorm, the large-scale and mesoscale systems facilitated the water vapor transport while they both reduced the supply of water vapor during the dispersion period of the rainstorm, suggesting that the mesoscale system plays an important role in the supply of water vapor during the development of a rainstorm.
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2013年第1期56-62,69,共8页
Journal of Lanzhou University(Natural Sciences)
基金
国家公益性行业(气象)科研专项(GYHY200806029)
国家大学生创新性实验计划项目(091073028)
关键词
暴雨
诊断分析
尺度分离
中尺度系统
rainstorm
diagnostic analysis
scale separation
mesoscale system
