河西走廊夏季旱涝和典型暴雨的水汽特征  

Water Vapor Characteristics of Summer Drought and Flood and Typical Rainstorm in Hexi Corridor

作　　者：李玲萍 王博 李天江 李晓京 LI Lingping;WANG Bo;LI Tianjiang;LI Xiaojing(Wuwei Meteorological Bureau,Wuwei 733000,Gansu,China;Gulang City Meteorological Bureau of Gansu Province,Gulang 733100,Gansu,China)

机构地区：[1]甘肃省武威市气象局,甘肃武威733000 [2]甘肃省古浪县气象局,甘肃古浪733100

出　　处：《高原气象》2023年第4期923-933,共11页Plateau Meteorology

基　　金：国家自然科学基金重点项目(42230611);武威市市列科技计划项目(WW190102)。

摘　　要：水汽源地和输送路径是影响我国河西地区旱涝模态的主要因素,也是该地区暴雨预报需要考虑的关键因子。本文利用1979-2018年的ERA-Interim再分析资料和常规观测资料,对比分析了河西走廊夏季不同环流形势典型暴雨的水汽输送特征差异以及与旱涝年水汽输送气候平均态的不同。结果表明:(1)夏季标准化降水指数SPI和整层水汽通量表明该区总体均呈现略偏干趋势走向,其变化倾向率分别为-0.04·(10a)^(-1)和-5.7 kg·(m·s)^(-1)·(10a)^(-1)。(2)夏季水汽主要来源为西北方(北冰洋)和西方(黑海和里海),其中旱年来自西北方,水汽通量<50 kg·(m·s)^(-1);涝年来自西方,水汽通量为50~100 kg·(m·s)^(-1);旱涝年各边界水汽输入主要来自西边界和北边界,区域水汽收支都为净流出。(3)两次暴雨过程均存在西路水汽输送,这和夏季涝年气候平均态一致,但还需中低层其他路径的水汽补充汇合并形成强的水汽通量辐合,区域水汽收支为净流入,其中西太平洋副热带高压西北侧低槽型暴雨水汽主要来自西路的里海、黑海,南路的南海和西南路的孟加拉湾,水汽通量最大中心达100~150 kg·(m·s)^(-1),水汽输入主要来自南边界和西边界;河套异常高压型暴雨水汽来自东路的黄海、西路的里海和黑海、西南路的孟加拉湾,异常偏东气流将三路水汽接力式地输送到暴雨区,水汽通量最大中心达250~300 kg·(m·s)^(-1),水汽输入主要来东边界和南边界。Water vapor source and transport path are main factors of affecting drought-flood mode in Hexi region of China,and also key factors to be considered in the rainstorm forecast in this region.Using conventional observations and ERA-Interim reanalysis data from 1979 to 2019,the differences of water vapor transport characteristics of summer typical rainstorms in different circulation conditions and the average climate state of water vapor transport in drought-flood years were comparatively analyzed in Hexi Corridor.The results showed that:(1)The summer standardized precipitation index SPI and the whole layer water vapor flux showed a slightly more dry trend,with change tendency rate of -0.04·(10a)^(-1) and-5.7 kg·(m·s)^(-1)·(10a)^(-1),respectively.(2)The main sources of summer water vapor were northwest(Arctic Ocean)and west(Black Sea and Caspian Sea),among which the drought year was from northwest whose water vapor flux was less than 50 kg·m^(-1)·s^(-1),the flood year was from west whose water vapor flux was 50~100 kg·m^(-1)·s^(-1);in drought-flood years,the water vapor input was mainly from boundaries of west and north,and all regional water vapor expenditure was net outflow.(3)Both of two typical rainstorms had water vapor transport along west road,which was consistent with climate average state of summer flood years,but the water vapor supplement and confluence of other paths in the middle and low atmosphere layers were still needed which formed strong water vapor flux convergence,the regional water vapor income and expenditure was a net inflow,the water vapor of low trough rainstorm on northwest side of the Western Pacific Ocean subtropical high was mainly from west road of Caspian Sea and Black Sea,south road of South China Sea and southwest road of the Bay of Bengal,whose maximum center of water vapor flux was 100~150 kg·m^(-1)·s^(-1),the water vapor input was mainly from south boundary and west boundary;the water vapor of rainstorm in Hetao block high was from east road of Bohai Sea,west road of Cas

关 键 词：河西走廊 旱涝 暴雨 水汽输送 水汽净收支 

分 类 号：P426[天文地球—大气科学及气象学]