青藏高原东侧甘孜云雷达观测的非降水云垂直结构特征分析  

Vertical structure of non-precipitation cloud obtained from cloud radar observation at Ganzi in the eastern Qinghai-Tibet Plateau

作　　者：万霞[1] 徐桂荣[1] 万蓉[1] 王斌[1] 任靖 罗成 WAN Xia;XU Guirong;WAN Rong;WANG Bin;REN Jing;LUO Cheng(Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research,Institute of Heavy Rain,Wuhan 430205;Sichuan Province Ganzi Meteorological Service,Ganzi 626799)

机构地区：[1]暴雨监测预警湖北省重点实验室中国气象局武汉暴雨研究所,武汉430205 [2]四川省甘孜县气象局,甘孜626799

出　　处：《暴雨灾害》2020年第5期442-450,共9页Torrential Rain and Disasters

基　　金：国家自然科学基金高原专项重点项目(91637211);湖北省气象局科技发展基金项目(2015Q10)。

摘　　要：利用青藏高原东侧甘孜站Ka波段云雷达2019年6—8月观测资料,对该地区非降水云垂直结构特征进行了分析。结果表明:(1)甘孜非降水云中单层云的出现率为78.3%,高于两层云的出现率18.3%和多层云的出现率3.4%。分不同高度云来看,低云的出现率为46%,中云和高云各占27%,当云层数增加时,中云和高云的出现率增加。(2)云的出现率具有白天小、夜间大的日变化特征,云层数增多后,上层云出现率的日变化特征减弱;地形对云出现率的日变化有一定影响。(3)云底高和云顶高的垂直分布结构多为双峰形态,当出现三层云时,下层云的垂直结构为单峰形态。(4)甘孜云厚呈现出云压缩现象:单层云的平均云厚约为3.8 km;两层云的下层云平均云厚约为2.5 km,上层云平均云厚约为1.5 km;三层云的下层云平均云厚减小至约1.8 km,上层云平均云厚减小至约1.2 km,中层云平均云厚最小,约为1 km;云压缩现象随云层数增加而愈发明显。地基云雷达展示了局地云探测的优势,有益于高原云探测和研究。Based on the observation data of Ka-band cloud radar at Ganzi site in the eastern Qinghai-Tibet Plateau(QTP)from June to August 2019,the vertical structure of non-precipitation cloud in this area is analyzed.The results show that:(1)The cloud occurrence frequency(COF)of single-layer cloud is 78.3%,which is higher than 18.3%of two-layer cloud and 3.4%of multi-layer cloud under the cloudy condition.For clouds with different height,the COF of low cloud is 46%,while middle and high clouds account for 27%each.When the number of cloud layers increases,the COFs of middle and high clouds increase.(2)The COF presents a diurnal variation,in which it is low in daytime and high in nighttime.However,the COF diurnal variation of upper layer clouds weakens,when the number of cloud layers increases.Additionally,terrain has a certain impact on the COF diurnal variation.(3)The vertical distributions of cloud base height(CBH)and cloud top height(CTH)are mostly bimodal.When three-layer cloud happens,the vertical distributions of CBH and CTH are unimodal for the lower layer cloud.(4)The cloud thickness shows the phenomenon of cloud compression.Namely,for single-layer cloud,the average cloud thickness is about 3.8 km.For two-layer cloud,the average cloud thickness of lower layer cloud is about 2.5 km,and that of upper layer cloud is about 1.5 km.For three-layer cloud,the average cloud thickness of lower and upper layer clouds decrease to about 1.8 and 1.2 km,respectively,and the average cloud thickness of middle layer cloud is the smallest,with a value about 1 km.The phenomenon of cloud compression becomes more obvious with the increase of cloud layers.These results indicate that ground-based cloud radar shows the advantages of local cloud detection,which is beneficial to cloud detection and research over the QTP.

关 键 词：青藏高原 毫米波云雷达 云出现率 云垂直结构 

分 类 号：P426.5[天文地球—大气科学及气象学]