西天山地区一次冷锋暴雪微物理特征分析  

Microphysical Characteristics of A Cold Front Snowstorm Event in the West Tianshan Mountains

作　　者：刘凡 张晋茹 刘晶[1,2,3] 杨莲梅 LIU Fan;ZHANG Jinru;LIU Jing;YANG Lianmei(Institute of Desert and Meteorology,China Meteorological Administration,Urumqi 830002;Xinjiang Cloud Precipitation Physics and Cloud Water Resources Development Laboratory,Urumqi 830002;Field Scientific Observation Base of Cloud Precipitation Physics in West Tianshan Mountains,Urumqi 830002)

机构地区：[1]中国气象局乌鲁木齐沙漠气象研究所,乌鲁木齐830002 [2]新疆云降水物理与云水资源开发实验室,乌鲁木齐830002 [3]西天山云降水物理野外科学观测基地,乌鲁木齐830002

出　　处：《大气科学》2023年第2期417-429,共13页Chinese Journal of Atmospheric Sciences

基　　金：国家重点研发计划“重大自然灾害监测预警与防范”重点专项2018YFC1507102;中央级公益性科研院所基本科研业务费专项资金项目IDM2020002;国家自然科学基金项目U2003106;中亚大气科学研究基金项目CAAS201916;中国沙漠气象科学研究基金项目Sqj2018007。

摘　　要：基于二维视频雨滴谱仪联合毫米波云雷达、风廓线雷达、微波辐射计、GPS/MET水汽等垂直探测设备,对2020年2月18~19日西天山地区一次冷锋暴雪过程进行了微物理特征研究。本文设计了雪花及霰粒子分类算法,用于定量研究降雪微物理特征。结果表明:(1)冷锋入侵、动力强迫阶段,降雪粒子类型主要为雪花,微物理过程主要为凝华增长及聚并增长;(2)冷锋控制、大风降温阶段,降雪粒子类型主要为雪花、霰粒子,微物理过程主要是聚并增长及凇附过程,同时聚并增长有利于凇附过程的发生;(3)在冷锋过境阶段,由于云顶温度升高、大气冰核减少、充足的过冷水,有利于凇附过程的发生。不同于南京地区的降雪,西天山地区降雪,雪花直径及雪强偏小,但霰粒子对雪强有较大贡献。通过两种融化模型,拟合出相应的雨滴谱及其Gamma分布,发现与本地层状云降水的特征相似。Based on a two-dimensional video disdrometer,combined with cloud radar,wind profile radar,microwave radiometer,GPS/MET water vapor,and other vertically-scanning instruments,the microphysical characteristics of a cold front snowstorm event in the West Tianshan Mountain on February 18 and 19,2020,were analyzed and studied.A classification algorithm for the snowflake and graupel was designed to quantitatively study the microphysical characteristics of the snowfall.The results show that(1)in the cold front invasion and dynamic forcing stage,the precipitation particles are mainly snowflakes and the microphysical processes are deposition and aggregation;(2)in the stage of cold front control bringing wind chill,the precipitation particles are snowflakes and graupel,and the microphysical processes are aggregation and riming,with the aggregation exhibiting a positive impact on the riming;(3)in the cold front passage,less ice nucleation and enough subcooled water favor riming due to the rise of the cloud top temperature.Unlike those in Nanjing,the snowflake diameter and snow intensity in the West Tianshan Mountains are relatively small,but graupel has a greater contribution to the snow intensity.The raindrop size and Gamma distributions are fitted using two melting models,similar to the characteristics of local stratiform cloud precipitation.

关 键 词：西天山地区 固态降水 凇附过程 微物理特征 

分 类 号：P412[天文地球—大气科学及气象学]