山西一次回流倒槽降雪过程的飞机观测研究  

Aircraft Observation and Study on the Snowfall Process Affected by Reflux Inverted Trough in Shanxi

作　　者：封秋娟 牛生杰[2] 侯团结 岳治国[5] 申东东 FENG Qiujuan;NIU Shengjie;HOU Tuanjie;YUE Zhiguo;SHEN Dongdong(Shanxi Artificial Precipitation Enhancement and Lightning Protection Technical Center,Taiyuan 030032,Shanxi,China;College of Atmospheric Physics,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Key Laboratory of Cloud-Precipitation Physics and Weather Modification(CPML),China Meteorological Administration(CMA),Beijing 100081,China;China Meteorological Administration Weather Modification Centre,Beijing 100081,China;Shaanxi weather modification center,Xi′an 710016,Shaanxi,China)

机构地区：[1]山西省人工增雨防雷技术中心,山西太原030032 [2]南京信息工程大学大气物理学院,江苏南京210044 [3]中国气象局云降水物理与人工影响天气重点开放实验室,北京100081 [4]中国气象局人工影响天气中心,北京100081 [5]陕西省人工影响天气中心,陕西西安710016

出　　处：《高原气象》2023年第4期1044-1054,共11页Plateau Meteorology

基　　金：山西省基础研究计划面上项目(20210302123358);国家重点研发计划项目(2019YFC1510301);山西省气象局重点项目(SXKZDDW20217104);山西省重点研究计划项目(202202130501020)。

摘　　要：2019年11月29日山西出现一次回流倒槽系统影响的降雪过程。利用机载云物理探测数据,研究了此次降雪过程云微物理结构和冰粒子增长的演变特征。雷达观测显示在强度5~15 dBZ的不均匀片状回波中镶嵌有15~25 dBZ的块状回波。第一次探测云内液态水分布在云的上部,云顶温度-10℃冰雪晶呈板状,云内冰雪晶形态以板状、针状为主;通过凝华增长主要生成小于200μm的小冰晶且数浓度最大值为297 L^(-1),雪花最大直径为1700μm位于2000 m,2000 m以下由于相对湿度减小导致大部分雪花未到达地面。第二次探测云内基本无液态水,云顶温度-12.5℃冰雪晶呈辐枝状,云内冰雪晶形态为板状、针状、大量辐枝状及聚合体;通过凝华和攀附增长N200(粒子直径大于200μm的冰雪晶数浓度)和冰雪晶最大直径分别在-11℃和-2℃出现极大值,冰雪晶谱出现第二峰值,近地面形成雪花最大直径为2800μm。通过平飞观测发现云内粒子水平分布不均匀,冰水含量和冰雪晶数浓度大的区域以辐枝状和聚合体冰雪晶为主,聚合增长是雪花重要增长方式。将FY-4A卫星反演云内粒子相态与飞机观测结果进行对比检验,发现两者具有较好的一致性。On 29 November 2019,there was a snowfall process in Shanxi affected by the reflux inverted trough system.Based on the airborne cloud physics data,the evolution characteristics and ice crystal particle growth of the snowfall process were analyzed.The results show that snowfall radar echo was embedded with 15~25 dBZ block echo in the uneven sheet echo with intensity of 5~15 dBZ.In the first detection the liquid water content was mainly distributed in the upper part of the cloud.When the cloud top temperature was-10℃,the ice and snow crystals were plate,and the ice and snow crystals observed in the cloud were mainly plate and needle.The maximum ice crystal number concentration was 297 L^(-1),which generated by deposition growth to less than 200μm.The maximum diameter of snowflakes was 1700μm located at 2000 m.Below 2000 m,most snowflakes did not reach the ground due to the decrease of relative humidity.In the second detection there was basically no liquid water in the cloud.When the cloud top temperature was -12.5℃,the ice and snow crystals were dendrite.There were a large number ice and snow crystals of plate,needle,dendrite and aggregate observed in the cloud.The maximum N200(Ice and snow crystal number concentration which particle diameter greater than 200μm)and maximum diameter of ice and snow crystals appeared at -11℃ and -2℃respectively through condensation and aggregation growth.The second peak appeared in the crystal spectrum of ice and snow.The maximum diameter of snowflakes near the ground was 2800μm.Through the observation of massive snowfall,it was found that the horizontal distribution of microphysical characteristics of particles in cloud was uneven.The cloud with high ice water content and ice snow crystal number concentration were dominated by large dendritic ice and snow crystals and aggregates.Aggregation growth was an important way of snow growth.The phase states of the particles in the cloud retrieved by the FY-4A satellite were consistent with those measured by the aircraft.

关 键 词：降雪云 回流倒槽 微物理特征 飞机观测 

分 类 号：P481[天文地球—大气科学及气象学]