一次层状云弱降水过程的机载Ka波段云雷达探测特征分析  

Detection characteristics of stratiform cloud during a weak precipitation process by airborne Ka-band precipitation cloud radar

作　　者：孙国德 蔡兆鑫 张佃国[6] 王烁 易田 SUN Guode;CAI Zhaoxin;ZHANG Dianguo;WANG Shuo;YI Tian(CMA Key Open Laboratory of Transforming Climate Resources to Economy,Chongqing 401147,China;Qianjiang Meteorological Bureau of Chongqing,Chongqing 404100,China;Qianjiang District Key Laboratory of Strong Weather Research in Southeast Chongqing,Chongqing 404100,China;Shanxi Meteorological Disasters Defense Technology Center,Taiyuan 030032,China;CMA Weather Modification Centre,Beijing 100081,China;Shandong Weather Modification Office,Jinan 250031,China)

机构地区：[1]中国气象局气候资源经济转化重点开放实验室,重庆401147 [2]重庆市黔江区气象局,重庆黔江404100 [3]渝东南强天气研究黔江区重点实验室,重庆黔江404100 [4]山西省气象灾害防御技术中心,山西太原030032 [5]中国气象局人工影响天气中心,北京100081 [6]山东省人民政府人工影响天气办公室,山东济南250031

出　　处：《海洋气象学报》2024年第3期107-114,共8页Journal of Marine Meteorology

基　　金：国家自然科学基金项目(42175099);重庆市气象部门业务技术攻关项目(YWJSGG-202217);山东省自然科学基金项目(ZR2020MD054)。

摘　　要：利用2019年11月17日一次层状云系弱降水过程中获取的机载Ka波段云雷达(Ka-band precipitation cloud radar,KPR)和云粒子测量系统(droplet measurement technologies,DMT)资料,将利用云粒子谱正演得到的雷达反射率因子(Z_(c))与KPR探测值(Z_(m))进行对比,并对影响两者偏差的成因进行探讨分析。结果发现:(1)在层状云内部,Z_(c)与Z_(m)有很好的一致性,两者之间的偏差和均方根偏差分别为4.1 dBZ和4.3 dBZ。(2)在KPR径向速度变化和速度谱宽较大的区域,或在云层比较薄的区域,Z_(c)与Z_(m)之间的偏差和均方根偏差变大,但在雷达反射率因子的变化趋势上有较好的一致性。(3)云粒子数浓度(N_(c))、云粒子有效直径和云中液态水含量的变化均对Z_(c)与Z_(m)之间的偏差有一定的影响,但偏差总体控制在±10 dBZ范围内。随着N_(c)的增大,两者之间的偏差变小,当N_(c)>200 cm^(-3)时,偏差大于10 dBZ的时次极少。当有效直径在50~230μm、液态水含量在0.15~0.50 g·m^(-3)范围内时,Z_(c)<Z_(m);当有效直径大于230μm、液态水含量大于0.50 g·m^(-3)时,Z_(c)>Z_(m)。Based on the data of airborne Ka-band precipitation cloud radar(KPR)and droplet measurement technologies(DMT)obtained during a weak precipitation process of stratiform cloud system on 17 November 2019,the radar reflectivity(Z_(c))calculated with the detected cloud particle spectrum is compared with the KPR observation(Z_(m)),and the causes of the deviation are discussed.The results are as follows.(1)Inside the stratiform cloud,Z_(c)and Z_(m)are in good agreement with a deviation and root mean square error of 4.1 dBZ and 4.3 dBZ,respectively.(2)The deviation and root mean square error between Z_(c)and Z_(m)are larger in areas with larger variation of KPR’s radial velocity and velocity spectrum width,or in thin cloud area,but there is a good consistency in the variation trend of radar reflectivity.(3)The variation of cloud particle number concentration(N_(c)),cloud particle effective diameter and cloud liquid water content all have certain influence on the deviation between Z_(c)and Z_(m),but the deviation is generally controlled within the range of±10 dBZ.With the increase of N_(c),the deviation between the two becomes smaller;when N_(c)is greater than 200 cm^(-3),the deviation greater than 10 dBZ is rare.Z_(c)is smaller than Z_(m)when the effective diameter is between 50 and 230μm and the liquid water content is between 0.15 and 0.50 g·m^(-3);Z_(c)is greater than Z_(m)when the effective diameter is greater than 230μm and the liquid water content is greater than 0.50 g·m^(-3).

关 键 词：Ka波段云雷达(KPR) 飞机观测 云微物理结构 

分 类 号：P426.5[天文地球—大气科学及气象学]