不同天气系统影响下强降雨过程GPS可降水量变化特征对比  

Variation Characteristics of GPS Precipitable Water Vapor During Typical Heavy Rainfall Processes Under Different Synoptic Systems

作　　者：杨璐瑛[1] 刘畅[2] 杨成芳[2] 韩永清[2] YANG Luying;LIU Chang;YANG Chengfang;HAN Yongqing(Department of Science,Technology and Forecasting of Shandong Meteorological Bureau,Jinan 250031,China;Shandong Meteorological Observatory,Jinan 250031,China)

机构地区：[1]山东省气象局科技与预报处,山东济南250031 [2]山东省气象台,山东济南250031

出　　处：《干旱气象》2018年第3期475-482,共8页Journal of Arid Meteorology

基　　金：国家自然科学基金项目(41475038);中国气象局预报员专项(CMAYBY2018-042);局校合作科研课题(2015qdqxh02)共同资助

摘　　要：利用常规地面高空观测资料、山东省123个自动站1 h降雨量资料和25个地基GPS反演的大气可降水量资料,对比分析不同天气系统影响下典型强降雨过程中的大气可降水量变化特征。结果表明:(1)降雨开始前水汽累积时间与天气系统尺度有密切关系,一般尺度越大,水汽积累时间越长,低槽冷锋强降雨前大气可降水量的积累时长可达约26 h,副高边缘强降雨发生前水汽积累时间仅5~6 h;(2)水汽增速与天气系统尺度密切相关。天气系统尺度越小增速越快,低槽冷锋强降雨发生前水汽增速小于2.0 mm·h^(-1),副高边缘强降雨发生前水汽增速可达3.1 mm·h^(-1);(3)短时强降雨发生前,水汽累积时间与积累速度呈反相关,即水汽增速越快,强降雨发生越快,当水汽增速大于2.0 mm·h^(-1),可降水量经历5~6 h积累即可产生短时强降雨;(4)一般强降雨时段多数在可降水量峰区时段,而副高边缘型短时强降雨和冷式切变线第1阶段强降雨均发生在可降水量增长时段。降雨过程结束后,一般情况下可降水量锐减,而副高边缘型和冷式切变线第1阶段强降雨结束后可降水量继续增长。冷式切变线第2阶段降雨结束后可降水量出现持续小幅减小,数小时后,可降水量再次增长。Based on conventional ground observations and high-altitude radiosonde,hourly precipitation data of 123 automatic meteorological stations in Shandong Province and atmospheric precipitable water monitored by 25 ground-based GPS,the variation characteristics of atmospheric precipitable water vapor（ PWV） during typical heavy rain processes under different weather systems were analyzed.The results are as follows：（ 1） The time length of water vapor accumulation before the rain was closely related to the spatio-temporal scale of weather systems. Usually,the larger the weather system scale is,the longer the accumulation time is. The water vapor accumulation time before heavy rain for cold-front and trough type was about 26 hours and it was only 5-6 hours before the beginning of heavy rain on the edge of Western Pacific Subtropical High（ WPSH）.（ 2） The growth rate of PWVwas also closely related to weather system scale. The rate was less than 2. 0 mm·h^（-1） in front of cold-front heavy rain case and about 3. 1 mm·h^（-1） for the heavy rain on the edge of WPSH.（ 3） The water vapor accumulation time before the heavy rain was inversely related to the water vapor growth rate. When water vapor growth rate was more than 2. 0 mm·h^（-1）,it took only 5-6 hours for water vapor accumulation before the heavy rain.（ 4） The beginning of heavy rain usually coincided with peak period of PWV. The heavy rain on the edge of WPSH was associated with increasing of the water vapor accumulation,which was similar to the first stage of the heavy rain caused by cold shear line. The PWVoften decreases sharply after the rain. However,it increased after the rain on the edge of WPSH and during the first stage of the cold shear line type. After the second stage of the cold shear line heavy rain,the PWVdecreased slightly. Moreover,the PWVincreased a few hours after the rain again.

关 键 词：典型强降雨 大气可降水量 演变特征 对比分析 

分 类 号：P458[天文地球—大气科学及气象学]