重庆地区一次雨转雪过程微物理特征分析  

A Case Study of Microphysical Characteristics During aRain to Snow Conversion in Chongqing

作　　者：张逸轩[1] 廖向花[1] 张丰伟 ZHANG Yi-xuan;LIAO Xiang-hua;ZHANG Feng-wei(Chongqing Weather Modification Office,Chongqing 401147,China;Gansu Weather Modification Office,Lanzhou 730030,China)

机构地区：[1]重庆市人工影响天气办公室,重庆401147 [2]甘肃省人工影响天气办公室,兰州730030

出　　处：《西南大学学报（自然科学版）》2020年第11期128-140,共13页Journal of Southwest University(Natural Science Edition)

基　　金：中国气象局大气探测重点实验室项目(KLAS201705);中国气象局云雾物理环境重点实验室开放课题项目(2017Z01605).

摘　　要：为了研究重庆地区雨转雪天气过程降水微物理特征,利用布设在重庆西部沙坪坝区气象站的一部MRR(Micro-rain Radar)微雨雷达及一台OTT Parsivel2雨滴谱仪探测到的2016年1月22-24日的雨转雪天气过程的垂直方向上的滴谱资料,对此次雨转雪天气过程的粒子下落速度、雷达反射率、粒子谱等微物理特征进行了分析.结果表明:雨滴谱仪及微雨雷达能较好地应用于云下垂直方向上的降水研究;此次过程,液(固)态降水中粒子平均直径、谱分布等特征具有明显差异,液态降水中表现为垂直下落方向上先减小后增大的特征,粒子以碰并增长为主,固态降水中垂直方向上各特征值则较为稳定;受仪器观测原理影响,雨转雪过程中粒子相态转变在微雨雷达观测特征量上表现为粒子下落速度均匀分布在1 m/s附近,粒子数浓度急剧增加1~2量级,回波反射率Z分布在10 dBZ附近.In order to understand the microphysical characteristics of precipitationin Chongqing,the vertical raindrop spectrarecorded during a rain to snow conversionon January 22-24,2016by MRR(micro rain radar)and OTT Parsivel2 raindrop spectrometer in Shapingba Weather Observatory of the citywere used to analyze the particle fallvelocity,radar reflectivity and particle spectra in this weather process.The results showed that the raindrop spectrometer and the micro-rain radar could wellbe applied to the study of precipitation vertically under the cloud;that during this precipitation process,the droplet mean diameter and droplet spectrum distribution of liquid precipitation were obviously different from thoseof solid precipitation:in liquid precipitation,a decrease was detected followed by an increase down from the cloud,caused by the collision-coalescence process,while in solid precipitation,the values of these microphysical characteristics were relatively stable;and that due to the principle of MRR observation,the phase change of particles in the process of rain to snow conversion was marked by the uniformly distributed falling velocity of particles around 1m/s,the dramatic increase of particle concentration by magnitude,and the Z distribution reflectivity around 10 dBZ.

关 键 词：微雨雷达 微物理特征 雨转雪过程 

分 类 号：P458[天文地球—大气科学及气象学]