对流降水云中大气垂直运动反演及个例试验  

Retrieval and Experiments of Atmospheric Vertical Motions in Convective Precipitation Clouds

作　　者：董佳阳 崔晔 阮征[2] 李南[1] 魏鸣[1] 李丰[2] Dong Jiayang;Cui Ye;Ruan Zheng;Li Nan;Wei Ming;Li Feng(Nanjing University of Information Science&Technology,Nanjing 210044;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081;Tianjin Meteorological Observation Center,Tianjin 300061)

机构地区：[1]南京信息工程大学,南京210044 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081 [3]天津市气象探测中心,天津300061

出　　处：《应用气象学报》2022年第2期167-179,共13页Journal of Applied Meteorological Science

基　　金：国家重点研发计划(2017YFC1501703);国家自然科学基金项目(41975046);中国气象科学研究院基本科研业务费项目(2020Z010);中国气象科学研究院科技发展基金(2020KJ021)。

摘　　要：为深入认识对流降水云结构及动力特征,基于降水频段调频连续波5520 MHz垂直指向雷达(VPR-CFMCW),使用地面至15 km高度的反射率因子及径向速度,建立对流降水云中大气垂直运动的反演方法,分析对流垂直结构及大气垂直运动随高度分布的演变特征。对在广东龙门测站探测的2019年4月20—22日前汛期4次对流降水进行反演试验发现,对流降水前大气上升运动对降水云反射率因子及地面降水有正贡献,深厚对流具有倾斜性,会导致垂直剖面在某些时刻呈分层结构;对流降水整层以下沉运动为主导,高层大气上升运动与下沉运动交替出现,低层大气下沉运动占比最高,大气上升运动在6 km高度以上占比有所增加;大气垂直速度在高层较大、在低层较小,超过10 m·s^(-1)的强上升运动与下沉运动多出现在6 km高度以上,4~6 km高度垂直运动变化较大,4 km高度以下的平均下沉运动小于5 m·s^(-1),上升运动约为2 m·s^(-1)。Detecting the vertical motions of the atmosphere in convective clouds is difficult.The cost of aircraft detection is expensive,limited by maximum flight altitude,high detection risk,low frequency,etc.In recent years,remote sensing instruments are applied with the development of detection technology.Groundbased vertical pointing radar has become a reliable way to obtain atmospheric vertical motions,through which the cloud structure and dynamic characteristics of convective precipitation clouds can be obtained,and the distribution and evolution characteristics of the intensity and proportion of atmospheric vertical movement during the mature stage of convection can be monitored in detail.Based on the vertical structure detection data of precipitation clouds from ground to 15 km height by a vertical pointing radar with5520 MHz C-band Frequency Modulation Continuous Wave(VPR-CFMCW) technology,the vertical motions in the convective precipitation cloud are retrieved,and the vertical structure of convection and evolution characteristics of vertical motions at different heights are analyzed.The VPR-CFMCW is used to carry out the atmospheric vertical motion retrieval experiments on 4 convective precipitation events at the Longmen Station in Guangdong Province during pre-monsoon from 20 April to 22 April in 2019.It is found that the updrafts of the atmosphere before convective precipitation have a positive contribution to the intensity of reflectivity and surface precipitation afterwards.The deep convection is inclined,which causes the vertical section to show a layered structure at certain moments.Convective precipitation is dominated by downdrafts of the entire level,updrafts and downdrafts of the upper-level atmosphere appear alternately,when downdrafts account for the highest proportion in the lower-level,and the updrafts account for an increased proportion above 6 km height.The intensity of atmospheric vertical motions is strong in the upper-level,as strong updrafts and downdrafts exceeding 10 m·s^(-1) mostly appear

关 键 词：垂直指向雷达 大气垂直运动反演 对流云垂直结构 对流云内垂直运动 华南前汛期 

分 类 号：P458.3[天文地球—大气科学及气象学] P407