利用雷达反射率因子垂直廓线改进复杂地形下的台风降水估测精度  

Improving Orographic Typhoon Quantitative Precipitation Estimation Through Radar-Based VPR Correction

作　　者：黄旋旋[1,2] 朱科锋 赵坤[1] HUANG Xuanxuan ZHU Kefeng ZHAO Kun(Key Laboratory of Mesoscale Severe Weather of the Ministry of Education, School of Atmospheric Sciences Nanjing University, Nanjing 210023 Ningbo Meteorological Bureau of Zhejiang Province, Ningho 315012)

机构地区：[1]南京大学中尺度灾害性天气教育部重点实验室,南京210023 [2]宁波市气象局,宁波315012

出　　处：《气象》2017年第10期1198-1212,共15页Meteorological Monthly

基　　金：公益性行业(气象)科研专项(GYHY201506006);国家自然科学青年基金项目(41405100);宁波市科技计划项目(2015C50054);宁波市气象科技计划项目(N13QX2014011B);浙江省科技厅公益项目[2016C33G20400061(2016C33012)]共同资助

摘　　要：文章发展了一种利用雷达垂直反射率因子廓线改进复杂地形下台风降雨的雷达定量估测方法。该方法通过全局与区域最优拟合的垂直反射率因子廓线(VPR)获取近地面的最优反射率,并获取最优的动态Z-R关系。该方法充分考虑了复杂地形下的垂直降雨结构特征以及地形增雨增幅影响,因此有效弥补了雷达在复杂地形下VPR监测不完整问题。利用浙江地区三个典型登陆台风对方法进行检验,结果表明,反演的VPR能够较好地反映洋面、平原与山区的低层反射率因子结构差异,符合实际降水系统低层结构特征。相比传统的定量降水估计方法.改进算法较好地解决了复杂地形区域的强降水低估问题,其估测的小时降水与地面检验的雨量站观测相关系数达到0.85~0.94,降水累积估测误差减少约50%。In this paper, an algorithm for improving the radar-based quantitative precipitation estimation （QPE） for orographic typhoon precipitation through vertical profiles of reflectivity （VPR） correction is de- veloped. With this method the optimal ground reflectivity and the optimal Z-R relationship are obtained simultaneously by the iterative solution of the objective function （the global and regional optimal fitting of VPR）. The vertical rainfall structure characteristics and the increase of rainfall in the complex terrain re- gion are fully considered and well corrected. Three typical typhoon cases are selected to verify the accuracy of this newly established method. The results show that the algorithm can display non-uniform VPR char- acteristics of the different regions of the ocean, plain and complex terrain region, being consistent with the observed structure of the low-layer precipitation clouds. Compared with other Z-R estimation algorithms, this improved scheme could better improve QPE in the complex terrain region. The correlation coefficient between the rainfall estimated by the new algorithm and the rain gauge observations is as high as 0. 85--0.94 and the estimation error is reduced by 50% or so.

关 键 词：复杂地形台风降水 雷达垂直反射率因子廓线 雷达定量降雨估测 

分 类 号：P413[天文地球—大气科学及气象学]