晴空回波的大气风温湿结构及双偏振雷达参量分析  

Analysis of Atmospheric Wind,Temperature and Humidity Structure and Dual-Polarization Radar Parameters of Clear Air Echo

作　　者：黄琴 魏鸣[1,2] 胡汉峰[1,2] ABRO Mohammad Ilyas HUANG Qin;WEI Ming;HU Hanfeng;ABRO Mohammad Ilyas(Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Naniing 210044;Key Laboratory for Aerosol-Cloud-Precipitation, CMA, Nanjing University of Information Science and Technology, Nanjing 210044)

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,南京210044 [2]中国气象局气溶胶与云降水重点开放实验室、南京信息工程大学,南京210044

出　　处：《气象》2018年第4期526-537,共12页Meteorological Monthly

基　　金：国家自然科学基金项目(41675029); 国家重点基础研究发展计划(973计划)(2013CB430102); 地理信息科学教育部重点实验室开放研究基金资助项目(KLGIS2015A01); 中国气象科学研究院灾害天气国家重点实验室开放课题(2016LASW-B12)共同资助

摘　　要：晴空回波有助于认识大气的风温湿结构,双偏振多普勒天气雷达为探测晴空大气提供了丰富信息。本文以2015年夏季南京信息工程大学C波段双偏振雷达探测的晴空回波为例,结合探空资料分析大气风温湿结构及晴空回波的影响因素,分析了晴空大气的反射率因子Z、径向速度Vr以及差分反射率因子ZDR回波特征。研究表明:大气温、压、湿梯度造成折射指数分布不均以及背景风场引起的湍流增强,均可造成晴空回波,其回波机理为湍流散射;差分反射率因子受到多普勒效应的影响;在风场及大气湍团干湿特性不同的情况下,晴空回波的差分反射率因子呈现不同的特征。研究结果有益于深入认识大气风温湿结构特征对雷达电磁波的散射的影响以及雷达资料质量控制。Clear air echo（CAE）helps to understand the structure of wind,temperature and humidity of the atmosphere;dual-polarization Doppler weather radar provides a wealth of information in detecting atmosphere.In this paper,CAE of Nanjing University of Information Science and Techonogy,C-Pol dual-polarization radar in summer of 2015 is taken as cases to analyze the wind,temperature and humidity structure of atmosphere and the impact factors of CAE,combined with the sounding observations.The characteristics of radar reflectivity factor Z,radial velocity Vrand differential reflectivity factor ZDR of CAE are analyzed.The results show that the uneven distribution of refractive index caused by the temperature,pressure and humidity gradients and the turbulence enhancement induced by the background wind field can cause the clear sky echo.The echo mechanism is turbulent scattering.The differential reflectivity factor is affected by the Doppler effect.The ZDRof CAE has different characteristics in different wind and air turbulence situations.The results are helpful for better understanding the impact of atmospheric wind,temperature andhumidity structure on radar electro-magnetic scattering and the quality control of radar data.

关 键 词：晴空回波 双偏振雷达 湍流散射 大气风 温湿结构 

分 类 号：P412[天文地球—大气科学及气象学]