凉山州东移型强降水的环流和物理量场分析  

Analysis of Circulation and Physical Quantity Field of Eastward Heavy Rainfall in Liangshan Prefecture

作　　者：吕俊杰 牟端霞 LYU Junjie;MOU Duanxia(Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province,Chengdu 610072,China;Liangshan Meteorological Service,Xichang 615000,China;Nanchong Key Laboratory of Strong Weather Research in Northeast Sichuan,Nanchong 637000,China)

机构地区：[1]高原与盆地暴雨旱涝灾害四川省重点实验室,成都610072 [2]四川省凉山州气象局,西昌615000 [3]川东北强天气研究南充市重点实验室,南充637000

出　　处：《高原山地气象研究》2023年第S01期7-12,共6页Plateau and Mountain Meteorology Research

基　　金：白鹤滩水电站气象保障服务实鉴(JGAJ0422015)。

摘　　要：利用NCEP再分析资料、FY-2G静止气象卫星资料和降水资料,通过合成平均方法分析了2019—2021年6—9月凉山州东移型强降水的环流和物理量场特征。结果表明:特殊的地形条件有利于对流的触发,冕宁“喇叭口”地形对于攀西地区低层南风属于迎风坡,气流爬升有利于触发对流;700hPa低涡切变和850hPa低涡长时间稳定又导致能量锋和水汽辐合中心的生成,同时攀西地区低层南风源源不断的水汽输送使凉山北部成为高能高湿的不稳定区,更加有利于对流的生成、发展和长时间维持;发展东移型的南亚高压脊线略偏南,高空辐散有利于加强中低层上升运动的发展维持。原地发展型的南亚高压脊线略偏北,高空辐合削弱了上层的上升运动,但中低层上升运动仍然较强,所以与发展东移型相比,降雨量级略小,但也可达暴雨。Based on NCEP reanalysis data,FY-2G geostationary meteorological satellite data and precipitation data,the circulation and physical quantity field characteristics of eastbound heavy precipitation in Liangshan Prefecture from June to September during 2019—2021 were analyzed by synthetic averaging method.The results showed that the special topographic conditions were favorable to trigger the convection.Trumpet-shaped topography of Mianning area belonged to the windward slope for the south wind in the low level of Panxi area,and the airflow climbing was favorable to trigger the convection.The 700 hPa vortex shear and 850 hPa vortex were stable for a long time to lead to the formation of energy front and water vapor convergence center.At the same time,the continuous moisture transport from the lower southerly winds in the Panxi region had made the northern part of Liangshan be an unstable region with high energy and humidity,which was more conducive to the generation,development,and long-term maintenance of convection.The ridge line of the eastward-moving South Asian high was slightly southerly,and the upper-level divergence was conducive to strengthen the development and maintenance of the mid-low-level ascending motion.The ridge line of the in-situ developing South Asian high was slightly northerly,and the upper-level convergence weakens the upward movement of the upper layer,but the upward movement of the middle and lower layers was still strong.Therefore,compared with the developing eastward type,the rainfall level was slightly smaller,but it could also be rainstorm.

关 键 词：低涡 地形 水汽辐合 垂直环流 

分 类 号：P426.611[天文地球—大气科学及气象学]