湖南两次不同类型致灾暴雨水汽特征分析  

Analysis of Water Vapor Transport for Disaster of Two Different Types of Rainstorms in Hunan

作　　者：胡燕 刘红武 曾钰婷 苏涛 刘焕乾 HU Yan;LIU Hongwu;ZENG Yuting;SU Tao;LIU Huanqian(Hunan Meteorological Observatory,Changsha 410000,China;Hunan Key Laboratory of Meteorological Disaster Prevention and Reduction,Changsha 410000,China;Meteorological Center of Southwest Air Traffic Administration,Chengdu 610000,China;Hunan Meteorological Observation Technology Support Center,Changsha 410000,China)

机构地区：[1]湖南省气象台,湖南长沙410000 [2]气象防灾减灾湖南省重点实验室,湖南长沙410000 [3]中国民用航空局西南空中交通管理局气象中心,四川成都610000 [4]湖南省大气探测技术保障中心,湖南长沙410000

出　　处：《灾害学》2022年第3期93-98,111,共7页Journal of Catastrophology

基　　金：中国气象局预报员专项(CMAYBY2020-085);湖南省气象局重点项目(XQKJ22A004);湖南省科技厅重点领域研发计划项目(2019SK2161);中国气象局创新发展专项(CXFZ2021Z033、CXFZ2021J020);湖南省业务能力建设(NLJS14)。

摘　　要：利用NCEP再分析资料,引入气块轨迹追踪模式(HYSPLIT v4.9),分析了湖南省2020年6月21—25日(过程一)、7月5—9日(过程二)两次不同类型强(特强)区域性致灾暴雨过程的成因,比较水汽特征差异。研究发现:①两次过程间隔时间短,落区重叠,洪涝灾害面积广,其中6月21—25日的强降雨产生于纬向环流背景下的副高边缘处,为副高边缘类暴雨;7月5—9日的暴雨产生于环流经向度大、斜压性强的大尺度背景下,为低涡冷槽型暴雨。②过程一水汽主要集中在800 hPa以下的对流层低层,过程二中低层水汽在降雨全阶段均表现为强汇合,最强降水时段水汽汇合层可达500 hPa,湿层深厚,两次过程水汽汇合中心均与暴雨区对应。③两次过程湘中以北暴雨区均有一支源于孟加拉湾的西南气流,比湿较大、传输高度较低。过程一水汽源于西太平洋,沿副高边缘传输的东南气流比湿大,过程二源于巴尔喀什湖的偏北气流比湿较小,这两支气流均是导致该区域持续性暴雨的关键水汽传输通道。④湘中以北区域暴雨主要流入边界是来自南海和孟加拉湾的南边界,南边界和西边界持续稳定向暴雨区输入水汽是长时间降雨的主要成因。There were two regional persistent rainstorms in Mid-northern Hunan Plateau in the flood season of 2020.Using Global Data Assimilation System(GDAS)data and reanalysis data from the National Centers for Environmental Prediction(NCEP),and introducing on the trajectory model of the air mass(HYSPLIT v4.9),the water vapor characteristics are comparatively analyzed in two rainstorm processes from June 21 to 25 and July 5 to 10 in 2020.The results showed:On June 21 to 25,the rainstorm was affected by the edge of subtropical high with zonal circulation,which was the type of the edge of subtropical high.On July 5 to 10,the rainstorm was affected by the upper-level trough and low level vortex with meridional circulation,which was the type of votex and cold-trough.The water vapor was mainly from the troposphere low-level under 800hPa in the type of the edge of subtropical high.The water vapor was mostly in the mid-lower levels,and water vapor convergence center corresponds to the area of heavy rainfall.In the type of votex and cold-trough,the water vapor convergence layer reached 500 hPa during the strongest rainfall period,and the wet layer was deeper.The water vapor sources of two different patterns rainstorms showed multi-source features,and the transport paths were different.There was a southwestly flow from the Bay of Bengal,with high specific humidity and low transport height in the two rainstorms in Mid-northern Hunan Plateau.In the type of the edge of subtropical high,the southeasterly flow was originated from the western Pacific and propagated along the edge of the subtropical high,which had the higher specific humidity.In the type of votex and cold-trough,the northerly flow from Lake Balkhash had the lower specific humidity.They were the key water vapor channels in the two rainstorms.The southern boundaries was mainly contributed to the south boundary of the two rainstorms in Mid-northern Hunan Plateau,which were the main inflow boundaries from the South China Sea and the Bay of Bengal.Sustained and stable water v

关 键 词：HYSPLIT模式 暴雨 副高边缘类 低涡冷槽类 水汽特征 湖南省 

分 类 号：X43[环境科学与工程—灾害防治] X915.5[天文地球—地质学] P692