2007年7月淮河流域暴雨过程天气学诊断计算与分析  

Synoptic Diagnostic Calculation and Analysis of Heavy Rain in the Huaihe River Basin during July 2007

作　　者：辜旭赞[1] 叶金桃[1] 陈郁琴[2] 

机构地区：[1]中国气象局武汉暴雨研究所,武汉430074 [2]湖北省气象信息与技术保障中心,武汉430074

出　　处：《暴雨灾害》2009年第2期131-136,共6页Torrential Rain and Disasters

基　　金：国家自然科学基金项目(40575053)资助

摘　　要：采用T213L31模式大气资料,在等熵坐标系上,对天气学凝结函数降水、水汽通量散度降水做诊断计算;又对对流不稳定降水和气块(团)不稳定降水做理想设计与诊断计算,用以对2007年7月淮河流域暴雨过程的诊断计算。分析表明:大尺度稳定性的凝结函数降水量级较小,天气尺度波动的水汽通量辐合降水虽量级较大,却都不足以形成暴雨,但是它们可以组织起对流性降水运动,被组织的对流不稳定降水则可以形成暴雨,但仍不足以形成大暴雨,只有参与层结不稳定降水,才可以形成大暴雨。因淮河流域高空锋区上多有高空槽及冷空气活动,且副热带高压偏强偏西,使得东亚季风进程中的长时间水汽通量辐合与高温高湿气团维持在淮河流域上空,并在地面静止锋上由凝结函数降水和水汽通量散度降水引发非等熵湿绝热运动的对流不稳定降水和层结不稳定降水,是淮河流域暴雨天气学成因。On the isentropic coordinates system, condensation-function precipitation, moisture flux divergence precipitation, wet- labile air layer convection precipitation and wet-labile air-parcel precipitation are diagnostic calculated with the re-analysis and forecast data of T213L31＇s model for the heavy rain in Huaihe River basin in July 2007. The condensation function precipitation movements and the moisture flux divergence precipitation movements are on the synoptic scale. The latter order of precipitation magnitude is larger than the former, but both are too smaller to form heavy rain. The wet-labile air layer convection motion may form heavy rain but not the rain gust, as more as the wet-labile air-parcel precipitation motion could be the only strong ascending mechanism of rain gust of its self-organization and positive feedback. Diagnostic calculation of synoptic precipitation shows that, because of the Western Pacific subtropical high slanting strong as well as declining to the west, there are condensation-function and moisture flux divergence precipitations under the trough activities in upper frontal zone, and the high temperature and the high moist air masses over the stationary front on the Huaihe River basin. Then, the high precipitable water air mass maintains for a long time and vapor is transported rapidly in progress of the East Asian monsoon, which leading to the non-isentropic saturation- adiabatic processes and coming into the ~st air layer convection, and the moist air mass instability precipitations, can be the synoptic causes of the heavy rain as well as the rain gust on the Huaihe River basin in July 2007.

关 键 词：凝结函数降水 水汽通量散度降水 对流不稳定降水 层结不稳定降水 淮河流域(大)暴雨 

分 类 号：P458.121.1[天文地球—大气科学及气象学] S426[农业科学—植物保护]