高原低涡切变影响云南强降水分布及水汽特征  

The Effect of Plateau Vortex Shear on the Heavy Precipitation Distribution and Water Vapor Characteristics in Yunnan

作　　者：杨倩媛 张万诚 闵颖[1,2] 朱莉 YANG Qianyuan;ZHANG Wancheng;MIN Ying;ZHU Li(Research Center for Disastrous Weather in Hengduan Mountains,China meteorological administration,Kunming 650034;Yunnan Meteorological Observatory,Kunming 650034;Yunnan Institute of Meteorological Sciences,Kunming 650034)

机构地区：[1]中国气象局横断山区低纬高原灾害性天气研究中心,昆明650034 [2]云南省气象台,昆明650034 [3]云南省气象科学研究所,昆明650034

出　　处：《大气科学》2024年第4期1565-1583,共19页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目42075013;第二次青藏高原综合科学考察研究项目2019QZKK0105;云南省科技厅重点研发计划——社会发展专项202203AC100005;云南省气象局科研项目YZ202445。

摘　　要：利用实况资料以及NCEP/NCAR再分析资料,对2008~2012年夏季东南移出高原且影响云南的高原低涡切变过程进行统计和对比分析。结果表明:高原低涡切变影响云南产生强降水主要分为后部冷空气较强型、高原低涡切变补充型以及东南移减弱型,影响云南产生强降水最多的是低涡切变东南移减弱型。强降水的主要区域是滇中及其以北地区,是高原低涡切变影响云南的典型区,这些区域的降雨主要发生在夜间。后部冷空气较强型的影响范围最大,能造成全省性强降水过程,但发生频率低。低涡切变东南移减弱型和高原低涡切变不断补充型,在滇缅之间均有高压(脊)维持。降水范围、水汽输送与副热带高压的位置、低涡切变经向度和发生时间有关。影响云南的高原低涡切变过程有明显的水汽净收入,主要是南北向的水汽收入,东西向的水汽收入远小于南北向。通过拉格朗日轨迹模式HYSPLIT对水汽路径的模拟表明,孟加拉湾是云南重要的水汽源地。当高原低涡切变影响云南中北部时,有来自高原的水汽输送,高原的水汽一部分是来自阿拉伯海,一部分来自孟加拉湾。气流在到达降水区域之前受下垫面影响,经历了多次的降水和蒸发过程。Using observational data and NCEP/NCAR reanalysis data,the characteristics of plateau vortex shear during the summer of 2008-2012 are analyzed.This phenomenon moves southeastward to Yunnan Province,resulting in heavy precipitation.The results show that these events are mainly divided into three types:The strong cold air behind plateau vortex shear,supplementation of plateau vortex shear,and weakening of the southeastward plateau vortex shear.Among them,the third type has the highest frequency in Yunnan.Northern-central Yunnan is the main area receiving heavy rainfall and is typically affected area of plateau vortex shear in Yunnan,with rainfall mainly occurring at night.The first type of event has the largest influence area,which can cause rainstorms throughout the province but is less frequent.During the second and third types of events,a high is maintained(ridge)between Yunnan Province and Myanmar.Precipitation area and water vapor transportation are influenced by subtropical high location,vortex shear meridionality,and the time.There is an obvious income of water vapor in Yunnan during these heavy rainfall events;the meridional moisture income is stronger than the zonal moisture output.Using the HYSPLIT model,water vapor transportation by rainstorms is analyzed.The Bay of Bengal is the most important water vapor source.In northern Yunnan,water vapor contributions from the Tibetan Plateau are important.Some moisture over the Tibetan Plateau comes from the region near the Arabian Sea,while other portions originate from the Bay of Bengal.Throughout this transportation,each air flow may experience several cycles of evaporation and precipitation influenced by the terrain.

关 键 词：高原低涡切变 强降水 水汽输送 云南 

分 类 号：P447[天文地球—大气科学及气象学]