黄河源区降水特点及气象成因分析  

Precipitation Characteristics and Its Meteorological Causes in the Source Region of the Yellow River

作　　者：温丽叶[1] 靳莉君[1] 刘静[1] 王鹏[1] WEN Liye;JIN Lijun;LIU Jing;WANG Peng(Hydrological Bureau of YRCC,Zhengzhou 450004,China)

机构地区：[1]黄河水利委员会水文局,河南郑州450004

出　　处：《人民黄河》2022年第1期21-25,57,共6页Yellow River

基　　金：国家重点研发计划项目(2017YFC0404404-05)。

摘　　要：黄河源区降水时空分布极不均匀,东南部雨水丰沛,是黄河流域的多雨中心之一。年内降水主要集中于夏季(6—8月),占年降水量的57.1%,汛期(5—9月)降水量占年降水量的85%,雨季、旱季分明。黄河源区主要有连阴雨和强降雨两种典型降雨类型,连阴雨平均每年出现1.8次,持续时间长、强度小;区域强降雨持续时间短,平均只有1 d,主要集中在7—8月,突发性强。形成典型降雨的200 hPa环流形势表现为南亚高压异常强大,黄河源区处于南亚高压中心区域或北部边缘的强高空辐散区内。500 hPa高度场分析发现,连阴雨期间6—8月主要受新疆低压槽、高原槽、印缅低压和高原切变线等系统影响,由副高影响形成的连阴雨主要出现在9月;形成强降雨的500 hPa天气系统与连阴雨相似,但副高对强降雨的影响更为明显,7—9月都可由副高形成强降雨天气。物理量场上,典型降雨期间,黄河源区处于湿度、气流垂直速度和假相当位温场大值区内,水汽、动力和热力条件非常有利,强降雨发生时,气流上升速度、比湿、假相当位温等都较连阴雨期间更强,更有利于降水。The spatial and temporal distribution of precipitation is extremely uneven in the source region of the Yellow River,the precipitati⁃on in the southeast of the region is especially abundant,which is one of the rainy centers in the Yellow River.The annual precipitation is mainly concentrated in summer(from June to August),accounting for 57.4%of the annual precipitation and the flood season(from May to September)precipitation accounts for 85%of the annual precipitation with distinct rainy and dry seasons.There are two typical rainfall situa⁃tions of continuous rain and heavy rainfall in the source region of the Yellow River.Continuous rain occurs 1.8 times per year on average,with long duration and low intensity.Regional heavy rainfall that lasts for one day on average,is mainly concentrated in July and August with short⁃duration and sudden intensity.The 200 hPa circulation situation forming typical rainfall shows that the South⁃Asian high is extremely strong,and the source region of the Yellow River is located in the central area of South⁃Asian high or the northern high⁃altitude divergence zone.On 500 hPa,the continuous rain period from June to August,is mainly affected by Xinjiang low pressure trough,plateau trough,India⁃Myanmar low pressure and plateau shear line.The continuous rain formed by the influence of subtropical high mainly occurs in September.The 500 hPa weather system that forms heavy rainfall is similar to continuous rain,but the influence of subtropical high on heavy rainfall is more obvious and the heavy rainfall can be formed by subtropical high from July to September.In the physical quantity field,during the typi⁃cal rainfall period,the source region of the Yellow River is in the high value area of humidity,vertical velocity and pseudo⁃equivalent poten⁃tial temperature field and the water vapor,dynamic and thermal conditions are very favorable.When the heavy rainfall occurs,the rising speed,specific humidity and pseudo⁃equivalent potential temperature are stronger than that o

关 键 词：气象成因 降水特点 连阴雨 强降雨 黄河源区 

分 类 号：P426.6[天文地球—大气科学及气象学] P448