高原气象2025，Vol.44Issue(3)：720-732,13.DOI:10.7522/j.issn.1000-0534.2024.00083
基于GPM观测的山谷风对伊犁河谷地形降水的影响研究
Research on the Impact of Mountain-Valley Wind on Topographic Precipitation in the Ili River Valley Based on GPM Observations
摘要
Abstract
Studying the impact of valley winds on terrain precipitation is crucial for gaining a deeper understand-ing of the mechanism of precipitation formation under complex terrain conditions.Based on GPM/DPR data from 2014 to 2021,the connected domain method was used to identify the summer terrain precipitation system in the Ili River Valley.Combined with the 10 m surface wind data from ERA5,the precipitation process was divided in-to valley wind type and mountain wind type.The spatiotemporal distribution,vertical structure,and macro and micro characteristics of precipitation in these two types of"trumpet mouth"terrain were compared and analyzed.The results show that valley wind precipitation is concentrated on the windward slopes of the southern and east-ern foothills of the valley,with the precipitation period mainly from noon to evening(12:00-20:00 Beijing time,same as after).Mountain wind precipitation is more abundant in the valley plain,with more precipitation occurring from night to morning(01:00-06:00).The average wind speed of valley wind(0.79 m·s-1)is 6.8%higher than that of mountain wind(0.74 m·s-1).The average near surface precipitation rate(R)and rain top height(STH)of valley wind and mountain wind precipitation are 1.32 mm·h-1,respectively 1.15 mm·h-1,5.90 km,5.72 km,statistics show a positive correlation between STH and R;Under the influence of uphill winds,the R,STH,mass weighted average diameter(Dm),and particle number concentration(dBNw)of valley wind precipitation increase under the influence of terrain uplift,reaching a maximum at an altitude of 2-3 km.The up-welling airflow formed on the windward slope promotes the condensation and coalescence of cloud droplets into raindrops;The average dBNw of valley wind precipitation(33.5)is nearly 3%smaller than that of mountain wind precipitation(34.5),while the average Dm of the former(1.63 mm)is 18.1%larger than that of the lat-ter(1.38 mm).Due to the lower radar reflectivity factor of mountain winds compared to valley winds in the liq-uid phase region below 0℃,when raindrops descend to the dry layer near the ground,the large droplets break and evaporate,resulting in more dBNw and smaller Dm.Valley winds affect the macroscopic structure and micro-physical processes of terrain precipitation.In future research on identifying the potential of terrain cloud artificial precipitation enhancement and numerical simulation of fine structure of precipitation in mountainous areas,atten-tion should be paid to the role and dynamic mechanism of valley winds.关键词
伊犁河谷/降水系统/山谷风/GPM/DPRKey words
Ili River Valley/rain cell/surface wind/GPM/DPR分类
天文与地球科学引用本文复制引用
王智敏,冯婉悦,杨璟,李圆圆,汪会,付亚鹏..基于GPM观测的山谷风对伊犁河谷地形降水的影响研究[J].高原气象,2025,44(3):720-732,13.基金项目
新疆维吾尔自治区自然科学基金项目(2022D01B182) （2022D01B182）
中国气象局高影响天气(专项)重点开放实验室开放课题 （专项）
中国沙漠气象科学研究基金项目(Sqj2023011) （Sqj2023011）
新疆气象局科技创新发展基金项目(MS202412) （MS202412）
