【摘要】 利用常规探空和地面实测资料,以发生在2001年7月26—27日山西省晋中市的一次区域性暴雨为例,对准地转Q矢量和非地转湿Q矢量在暴雨诊断中的应用进行了定量对比分析,结果表明:(1)Q矢量对暴雨的预报有一定的指示作用,降水前期700hPa诊断效果最好,但在暴雨的强度和落区上存在明显偏差。而湿Q矢量在各层对暴雨均表现出良好的诊断特性,其散度辐合区与暴雨区有较好的对应关系,其强锋生出现6小时后开始产生强降水,且暴雨区与强锋生中心基本吻合,700hPa表现尤为突出。(2)Q矢量锋生函数分布表现出典型的准地转特征,而湿Q矢量锋生函数分布则具有明显的中尺度特征,因此,Q矢量适宜于研究与天气尺度系统相关的大气运动,而湿Q矢量更适宜于研究天气尺度系统激发的次级环流。湿Q矢量较准地转Q矢量更能反映出暴雨的落区和暴雨的中尺度特性,在反映暴雨的强度上也更具优越性。更多还原

【Abstract】 Based on some routine observation when a regional storm rain in Jinzhong, Shanxi Province during 26—27 July 2001, the application of quasi-geostrophic Q- and wet-Q-vector are made. The analysis shows that (1) the quasi-geostrophic Q-vector is a good indicator for the heavy rain forecast specially at 700hPa level in the beginning stage of the rainfall, while the wet-Q-vector has a good diagnostic property on each level. (2) The distribution of Q-vector frontogenesis function has typical quasi-geostropic characteristic, but wet-Q-vector ones has apparent mesoscale characteristic. So quasi-geostropic Q-vector adapt to study of atmospheric motion associated with synoptic scale system,and wet-Q-vector adapt to the secondary circulation triggered by synoptic scale system.更多还原