定量测量降水量的回波结构自适应算法研究  

An examination of the self-adaption algorithms used in qualitative precipitation estimations

作　　者：魏鸣[1,2] 宋羽轩 张蕾[1] WEI Ming;SONG Yuxuan;ZHANG Lei(Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration,Nanjing University of Information Science&Technology,Nanjing 210044,China;Collaborative Innovation Center on Forecast and Evaluation of Meterological Disasters(CIC-FEMD),Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心,江苏南京210044 [2]南京信息工程大学中国气象局气溶胶-云-降水重点开放实验室,江苏南京210044

出　　处：《大气科学学报》2018年第5期676-683,共8页Transactions of Atmospheric Sciences

基　　金：国家自然科学基金资助项目(41675029);国家重点基础研究发展计划(973计划)项目(2013CB430102)

摘　　要：为提高临近预报中对流性降水估测的准确性,分析了统计法估算降水的局限性。依据降水物理机制和降水回波结构,研究雷达反射率因子定量测量降水量(QPE-Qualitative Precipitation Estimate)的自适应算法,旨在减少由于雨滴谱变化导致的Z-I关系不稳定所引起的降水量测量误差。同时考虑组合反射率因子RC和垂直液态水含量VIL两个参量对降水的影响,建立适于城市区域的动态自适应的Z-I关系,改进对强降水严重低估的问题。Currently,major challenges exist in the area of the quantitative precipitation estimations of convective short-term flooding caused by local heavy rainfall events.In this study,in order to improve the accuracy of the forecasting of the convective precipitation estimates,various currently used quantitative measurements methods for precipitation were summarized.Then,the limitations of these statistical methods for rainfall estimations were analyzed.It is known that different types of precipitation affect the accuracy of the precipitation estimates due to the variations in power,heat,and water vapor,which result in different micro-physical mechanisms and internal structures.Therefore,based on the physical mechanisms of the precipitation,along with the precipitation echo structures,the coefficient A and exponent b in the Z-I relationship become spatial functions rather than simple constants.Therefore,they can provide a theoretical basis for an adaptive method which can be effectively used to quantitatively estimate precipitation.In this research study,the mechanisms of convective precipitation,mixed precipitation,and stratiform precipitation were examined,and the echo structural features,precipitation micro-physical characteristics,and echo extinction laws were analyzed.It is known that multiple parameters have certain impacts on precipitation,such as composite reflectivity factors(CR)and vertical liquid water content(VIL).Therefore,it was necessary to first distinguish the three different types of precipitation from the structure,and then use statistical methods for the fitting process.The lg R C-lg I and R C-I data pairs were respectively utilized.Then,depending on the type of rain event and the corresponding Z-I relationship,the precipitation measurement errors were reduced which had resulted from the unstable Z-I relationship caused by changes in the rain events,in order to solve the problem of the serious underestimations of heavy rainfall events.The results of this study showed that the lg R C-lg I data pairs d

关 键 词：雷达 定量降水估计 回波 结构 自适应 

分 类 号：P412.25[天文地球—大气科学及气象学] TV125[水利工程—水文学及水资源] TU992.02[建筑科学—市政工程]