一次典型南海季风槽云系的双偏振雷达特征分析  

Characteristic Analysis of Dual Polarization Radar for the Typical South China Sea Monsoon Trough System

作　　者：邢峰华 黄彦彬[1] 李光伟[1] 敖杰[1] Xing Fenghua;Huang Yanbin;Li Guangwei;Ao Jie(Hainan Institute of Meteorological Science,Haikou 570203,China;Key Laboratory of South China Sea Meteorological Disaster Prevention and Mitigation of Hainan Province,Haikou 570203,China)

机构地区：[1]海南省气象科学研究所,海南海口570203 [2]海南省南海气象防灾减灾重点实验室,海南海口570203

出　　处：《海南大学学报（自然科学版）》2022年第4期354-363,共10页Natural Science Journal of Hainan University

基　　金：海南省自然科学基金(421QN372);国家自然科学基金(41975008);海南省气象局科研基金(hnqxSJ202121,hnqxZC202112)。

摘　　要：鉴于过往对于南海季风槽降水云系的研究多以数值模拟或气象卫星数据为主,而以双偏振雷达对其展开详细分析的研究却相对较少,因此为了加强海南省西沙永兴岛双偏振雷达在南海季风槽降水云系中的应用效果研究,笔者以2021年10月17日发生在海南省西沙永兴岛附近的一次典型南海季风槽所引起的热带扰动降水云系为基础,同时结合S波段双偏振天气雷达、地面自动站降水观测等资料对其展开了深入的分析与研究,结果表明:该次热带扰动云系主要受南海季风槽影响,南海海域高空风场存在明显辐合,叠加高空偏东急流带来了丰富水汽、副热带高压带明显西伸等多重因素在过境永兴岛期间发生持续性降水;该次热带扰动云系过程可分为3个阶段,在其第2和第3发展阶段对流属性占据主导地位,10:00~11:00期间混合云系垂直积分液态水含量及雷达回波顶高出现小幅跃升,且云系内部小部分区域在高空5 km以上高度出现弱的“Z_(DR)柱”现象;在混合云系发展成熟期(11:00~12:00),云系内部超过50 dBZ的区域主要集中在6 km以下的中低层,云系的差分反射率(Z_(DR))超过1 dB的区域面积显著变大,相关系数(CC)基本维持在0.9~1区间.In the previous study,the numerical simulation or meteorological satellite data were wildly used for the analysis on the precipitation system in the monsoon trough,however,the dual-polarization radar were few used.In the report,based on the tropical disturbance precipitation system caused by South China Sea monsoon trough near Yongxing Island(Oct.17,2021),combined with S-band dual-polarization radar and ground automatic precipitation observations,the application study on dual-polarization radar was performed.The results showed that the typical case is mainly affected by the monsoon trough in the South China Sea,the wind field has obvious convergence phenomenon with abundant water vapor,and the subtropical belt extend westward;the process can be divided into three stages,in which the convective properties dominate in the second and third stage of the mixed cloud system.From 10:00 to 11:00,the vertical liquid water content and radar echo top of the mixed cloud system increases suddenly,and there are weak“Z_(DR) column”phenomenon observed when the small parts of the cloud system were above 5 km;From 11:00 to 12:00,the areas exceeding 50 dBZ are mainly concentrated below 6 km,the areas whose differential reflectivity(Z_(DR))more than 1dB are significantly larger than that of the other stages,and the correlation coefficients(CC)are basically maintained in the range of 0.9-1.

关 键 词：双偏振雷达 南海季风槽 降水云系 特征分析 

分 类 号：P426.5[天文地球—大气科学及气象学]