藏东南墨脱地区季风期降水的垂直结构特征  

Vertical Structure Characteristics of Precipitation in Mêdog Area of Southeastern Tibet During the Monsoon Period

作　　者：文镓齐 王改利[1,2] 周任然 李冉 Wen Jiaqi;Wang Gaili;Zhou Renran;Li Ran(State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Science,Beijing 100081;Mêdog National Climate Observatory,Mêdog 860700)

机构地区：[1]中国气象科学研究院灾害天气国家重点实验室,北京100081 [2]墨脱国家气候观象台,墨脱860700

出　　处：《应用气象学报》2023年第5期562-573,共12页Journal of Applied Meteorological Science

基　　金：第二次青藏高原综合科学考察研究(2019QZKK0105);中国气象科学研究院基本科研业务费(2023Z009);中国气象科学研究院科技发展基金(2023KJ041)。

摘　　要：以2021年6—9月(季风期)藏东南水汽输送通道入口关键区墨脱布设的微雨雷达、降水现象仪和雨量计的观测数据为基础,对比不同仪器测量结果的一致性。将降水划分为对流云降水、层状云降水、浅层云降水3种类型,研究不同类型降水的雨滴谱分布、下落速度、降水率、液态水含量和雷达反射率因子的平均垂直分布特征。结果表明:微雨雷达、降水现象仪和雨量计测量结果一致性较好,微雨雷达和雨量计日降水量相关系数最高达到0.96,各相关系数的显著性水平较高;对流云降水的各微物理量特征值较大,雨滴在下落过程中碰并增长过程显著,雨滴数浓度迅速增加,在1~2 km高度处存在明显的上升气流;层状云降水回波强度较弱,反射率因子、降水率和液态水含量随高度降低有所增加,雨滴下落速度在垂直方向基本保持均匀,中等大小的雨滴浓度随高度不变,蒸发、破碎和碰并过程处于相对平衡状态;浅层云降水各微物理量较小,但随高度变化明显,垂直方向上为明显的负梯度变化,以雨滴的碰并过程为主。Precipitation is particularly important for the earth's climate system.Understanding the structural characteristics,microphysical processes and drop size distribution(DSD)of precipitation is very important for quantitative precipitation estimation with radar and improving microphysical parameter schemes of numerical weather prediction models.With the launch of the Second Tibet Plateau Scientific Expedition and Research(STEPS),Chinese Academy of Meteorological Sciences has deployed Ka-band cloud radar(KaCR),X-band dual polarization phased array radar(X-PAR),disdrometer,micro rain radar(MRR)and other detection equipment in Mêdog,filling the gap of cloud and precipitation observation in this area and provides data basis for studying the physical characteristics of clouds and precipitation.Mêdog is located at Yarlung Zangbo Grand Canyon,the entrance of the water vapor channel in southeastern Tibet.Influenced by the warm and humid airflow brought by the Indian Ocean monsoon,the precipitation of Mêdog during the monsoon period exceeds 60%of the annual precipitation.MRR is a low-cost,miniaturized vertical directional Doppler rain radar that can more accurately analyze the vertical structural changes of precipitation.Based on observation of the rain gauge,MRR and disdrometer set up at Mêdog National Climate Observatory from 1 June to 30 September in 2021,the consistency of different instruments is studied.The observed rainfall is classified into convective,stratiform and shallow precipitation types,and the average vertical distribution characteristics of different precipitation types are studied from the aspects of raindrop size distribution,falling speed,rain rate,liquid water content and radar reflectivity.The results show that the measurement of rain gauge,MRR and distrometer are highly consistent.The correlation coefficient of daily rainfall is above 0.89,and the highest correlation coefficient between MRR and rain gauge is 0.96.However,MRR overestimates weak precipitation and underestimate strong precipitation.T

关 键 词：微雨雷达 雨滴谱 墨脱 垂直结构 降水分类 

分 类 号：P426.6[天文地球—大气科学及气象学]