雷达反射率因子数据中的亮带自动识别和抑制  

Automatic Recognition and Removal of the Bright Band Using Radar Reflectivity Data

作　　者：肖艳姣[1,2] 刘黎平[2] 李中华 王红艳[2] 

机构地区：[1]中国气象局武汉暴雨研究所,湖北武汉430074 [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]湖北气象信息与技术保障中心,湖北武汉430074

出　　处：《高原气象》2010年第1期197-205,共9页Plateau Meteorology

基　　金：灾害天气国家重点实验室基金项目(2006LASW012);武汉暴雨研究所基本科研业务费专项(0602)资助

摘　　要：为了减轻雷达反射率因子数据中的亮带污染对雷达降水估计的影响,一种基于新一代天气雷达体扫资料自动识别零度层亮带平均高度、厚度和区域以及对亮带进行抑制的算法被提出。该算法首先利用近距离分层平均方法建立视反射率因子垂直廓线,然后基于亮带VPR曲线在融化层高度的显著弯曲特征来识别和抑制亮带。比较该方法识别的零度层亮带的平均高度和实测0℃等温层高度表明,前者比后者平均低0.5km。亮带的厚度大多在1～1.25km。亮带区域识别算法能合理地识别亮带反射率因子高值区,用经过亮带抑制后的体扫资料得到的组合反射率因子和反射率因子垂直剖面上的高值区被抑制掉,用经过抑制后的亮带区的所有反射率因子库建立的平均VPR在融化层高度的显著弯曲消失。通过亮带抑制后的雷达体扫资料将用于雷达降水估计。To alleviate the effect of contaminated reflectivity measurements by brightband on surface rainfall estimation, an automated algorithm that operates on volume scan reflectivity data from China New Generation Weather Radar （CINRAD） to identify the height, depth and region of the bright band and restrain the bright band reflectivities for every volume scan has been developed. First of all, the apparent Vertical Profile of radar Reflectivity （VPR） is reconstructed by averaging the layered reflectivities at near range. Then based on the prominent curvature of VPR of brightband, the brightband is identified and removed. A comparison of radar-deduced brightband heights with melting levels derived from temperature profiles measured with rawinsondes launched from nearby radiosonde shows that the brightband height is, on average, 0.5 km lower than the melting level. The thicknesses of brightband are mostly 1 km to 1.25 kin. The brightband areas can be recognized and removed effectively. After bright remoyal, the high reflectivity areas of compose reflectivity and vertical cross-section of reflectivity are restrained, and the marked curvature of mean VPR of brightband disappears. The volume scan reflectivity data through - bright removal will be used for radar rainfall estimation.

关 键 词：零度层亮带 自动识别 雷达 反射率因子垂直廓线 

分 类 号：P412.25[天文地球—大气科学及气象学]