基于时域有限差分法的冰晶粒子群多次散射特性  

Study of multiple scattering properties of ice crystal particle swarm based on the finite difference time domain method

作　　者：陈浩[1,2] 王金虎 魏鸣[1,2] 董佳阳[2] 刘宇琦 金子琪 Chen Hao1,2, Wang Jin-hu1,2,3, Wei Ming1,2, Dong Jia-yang2, Liu Yu-qi2, Jin Zi-qi1(1. Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China; 2. School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, China ;3. National Demonstration Center for Experimental Atmospheric Science and Environmental Meteorology Education, Nanjing University of Information Science and Technology, Nanjing 210044, Chin)

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中国气象局气溶胶-云-降水重点开放实验室,南京210044 [2]南京信息工程大学大气物理学院,南京210044 [3]南京信息工程大学大气科学与环境气象国家级实验教学示范中心,南京210044

出　　处：《兰州大学学报（自然科学版）》2018年第2期175-183,共9页Journal of Lanzhou University(Natural Sciences)

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)项目(2013CB430102);中国气象科学研究院灾害天气国家重点实验室开放课题项目(2016LASW-B12);2017年度中国气象局气溶胶与云降水重点开放实验室开放课题项目(KDW1703);南京信息工程大学人才启动基金项目(2016r028);南京信息工程大学大气物理学院天诺基业大学生科创基金项目;南京信息工程大学地球科学类实验课程创新项目(SYCX201710;SYCX201713;SYCX201619;SYCX201620);2017年江苏省大学生实践创新训练计划项目(Z201710300008)

摘　　要：为了精确地利用雷达回波信号反演降雪粒子的微观物理参数,建立满足Gamma谱分布的两类非球形降雪粒子群模型,利用XFDTD软件计算了这两类非球形冰晶粒子群模型在94 GHz频率下的雷达散射截面,分别为-37.690 0和-40.301 0dB·m^2,与简单叠加计算的结果对比后发现绝对误差分别达到0.334 4和0.733 7 dB.在冰水含量一定时,满足Gamma谱分布的两类非球形降雪粒子群模型在分别考虑多次散射和单次散射下雷达反射率因子的绝对误差分别为0.334 6和0.733 7 dB,因此粒子群的多次散射效应在实际气象探测中必须加以考虑.In order to accurately use the radar echo signal to retrieve the microphysical parameters of snow particles,nonspherical snow particle swarm models satifying the Gamma distribution were established, and the radar cross section（RCS） calculated by XFDTD software of the models at 94 GHz were respectively-37.690 0 and-40.301 0 dB·m^2, the absolute errors were 0.334 4 and 0.733 7 dB when compared with the results of the method of simple addition. When the ice water content was constant, the absolute error of radar reflectivity factor of the two kinds of nonspherical snow particle swarm models under multiple scattering and single scattering were 0.334 6 and 0.733 7 dB. The multiple scattering effects of particle swarm must be taken into account in the actual meteorological exploration.

关 键 词：时域有限差分法 广义洛伦兹Mie理论 冰晶粒子 雷达散射截面 多次散射 

分 类 号：P406[天文地球—大气科学及气象学]