2019年6月下旬中昆仑山北坡两场强降水对比分析  

Comparative Analysis of Two Heavy Precipitation Events on the North Slope of Middle Kunlun Mountains in Late June 2019

作　　者：唐鹏 张丽 陈天宇[1] 李静[1] 黄艳[1] TANG Peng;ZHANG Li;CHEN Tianyu;LI Jing;HUANG Yan(Hotan Meteorological Bureau,Hotan 848000,China)

机构地区：[1]和田地区气象局,新疆和田848000

出　　处：《沙漠与绿洲气象》2024年第2期27-34,共8页Desert and Oasis Meteorology

基　　金：新疆维吾尔自治区自然基金项目(2021D01A15);国家自然科学基金项目(41965002)。

摘　　要：利用常规观测、NECP 2.5°×2.5°和EC 0.25°×0.25°再分析等资料,对比分析2019年6月25日(简称“过程1”)和28日(简称“过程2”)中昆仑山北坡两场强降水过程。结果表明:两场过程影响系统均有高空西南急流、中层低值系统、低层辐合线;“过程1”强降水范围大,持续时间长,影响系统移动缓慢,冷空气从东西两侧进入昆仑山北坡,同时西太平洋副热带高压西侧西南风将大量水汽输送至昆仑山北坡,低层有偏东和偏北、偏西风辐合;“过程2”为分散、对流性强降水,低值系统移动迅速、对流层有逆温和不稳定层结,午后升温和低层弱辐合、山前偏北风是对流触发条件。中高层偏西偏南风水汽输送至昆仑山北坡,在低层合适的风场将水汽输送汇集到昆仑山北坡是强降水的关键“,过程1”水汽输送强度和厚度明显强于“过程2”。另外,地形对于降水的增幅表现在热力和动力两方面。Based on data collected from conventional weather stations,NCEP,and EC reanalysis,this study conducted an in-depth analysis of two significant precipitation events that occurred on the northern slope of the Central Kunlun Mountains on June 25 and 28,2019.The results showed that:The rainfall event on the 25th exhibited large-scale and prolonged attributes,while the event on the 28th was characterized as convective severe precipitation.The meteorological systems influencing these weather processes comprised the upper-level jet stream,middle-level low-pressure system,and low-level convergence line.On the 25th,the heavy precipitation system demonstrated slow movement,coinciding with the influx of cold air from the east and west into the northern slope of the Kunlun Mountains.The southwest wind originating from the western side of the West Pacific subtropical high transported a substantial volume of water vapor to the northern slope of the Kunlun Mountains.Furthermore,convergence of easterly,northerly,and westerly winds at the lower level was observed.In contrast,the low-pressure system associated with heavy precipitation on the 28th exhibited a rapid movement.Inversion and instability within the troposphere,coupled with afternoon warming,weak convergence at the lower level,and northerly winds in front of the mountain,served as trigger conditions for convective activity.The study findings emphasize the pivotal role of water vapor transport from west to south at middle and high levels,as well as the transport of water vapor by the wind field at lower levels,as key factors driving heavy rainfall.The intensity and thickness of water vapor transport were notably more pronounced on the 25th compared to the 28th.Notably,the analysis highlights the profound impact of topography on the precipitation process,influencing both thermal and dynamic aspects.

关 键 词：中昆仑山北坡 强降水 水汽 

分 类 号：P426.6[天文地球—大气科学及气象学]