3836C波段双线偏振多普勒雷达及其在一次降水过程中的应用研究  

Data Quality Analysis of 3836 C-Band Dual-linear Polarimetric Weather Radar and Its Observation of a Rainfall Process

作　　者：曹俊武[1] 刘黎平[1] 陈晓辉[2] 陈刚[2] 

机构地区：[1]中国气象科学研究院灾害天气国家重点实验室 [2]安徽四创电子股份有限公司,合肥230088

出　　处：《应用气象学报》2006年第2期192-200,257,共10页Journal of Applied Meteorological Science

基　　金：科技部科研院所技术开发研究专项"双线偏振雷达气象产品生成软件系统研制";安徽四创电子股份有限公司与中国气象科学研究院灾害天气国家重点实验室合作项目"双偏振雷达高端产品开发"共同资助。

摘　　要：该文介绍了2004年完成的在北京市气象局升级改造后的3836C波段双线偏振多普勒雷达的技术状况,并通过对2004年11月9日北京地区一次大范围层状云降水观测资料的分析,讨论了其探测资料的质量情况和对降水粒子的探测性能,同时还根据零度层亮带内不同相态降水粒子的散射和空间取向等特征建立了一种利用双线偏振雷达观测资料识别零度层亮带的方法,并利用该雷达的观测资料对识别结果做分析检验,最后讨论了零度层亮带内各种降水粒子相态的变化规律。研究结果表明:除线性退极化比LDR未作分析外,3836雷达探测到的这次降雨过程的分析结果与国外双线偏振雷达的研究结果相似,其对降水粒子相态结构的反映比较有效合理。建立的零度层亮带识别模式合理,识别得到的结果能反映零度层亮带的特征。通过对零度层亮带内各偏振参数的变化特点分析,从双偏振雷达测量参数的角度解释了“零度层亮带”现象的形成是由于在零度层以下的冰相粒子融化成大雨滴然后再裂碎为小雨滴,从而造成在该层内水平偏振反射率因子ZH、差分反射率因子ZDR先增大后减小、水平/垂直偏振波零延迟相关系数ρhv(0)先减小后增大的规律。The technical status of upgraded 3836 C-band Dual-linear Polarimetric Weather Radar （3836 radar） in Beijing Meteorological Bureau in 2004 is studied. Based on the large area stratus rainfall observation over Beijing on November 19, 2004, the 3836 radar＇s measurement quality and its detection ability are presented. According to the characteristics of the scattering and orientations of the precipitation particles with different phases in the space within the melting-layer （so-called bright band）, a model is established , in which the bright band can be identified by applying the fuzzy logic method to three polarimetric radar observation variables and the height. The radar measurements are used to assess the outputs from the model and discuss the variation features of different phased hydrometeors within the melting-layer . The results show that： ① the phase distribution structure of hydrometeors of the storm revealed by the 3836 radar data, except the LDR non-analysed data, is reasonable and similar to those from foreign polarimetric radars. ②The result from the established model based on the 3836 radar measurements is reasonable and able to reflect the feature of melting-layer. ③ Upon the polarimetric radar measurements, the melting-layer is characterized by a drop in ρhv（0） associated with Z and ZDR peaks, the cause is that the ice particles descend below 0 ℃ height, melt into large rain drops, and the break into more rain droplets,resulting in the variation rule that the ZH and ZDR increase first then decrease while ρhv（0） is just on the contrary in this layer. In additional, the maximum Z is observed at a higher altitude than that of the maximum ZDR and minimum of ρhi（0） . It indicates that the maximum eccentricity of melted hydrometeors occurs at a lower level in the atmosphere than that with the maximum size, assuming the largest particles are located near the reflectivity maximum. It is a preliminary study on examining the potential ability of polarimetric weather rad

关 键 词：3836C波段双线偏振多普勒雷达 资料质量 零度层亮带 降水粒子的相态结构 

分 类 号：P412.25[天文地球—大气科学及气象学]