摘要
单波段雷达用Z-LWC关系反演液态水因不同降水类型反演的液态水含量相差较大。利用双波段雷达回波强度偏差反演液态水含量,直接将双波段雷达基数据回波强度相减的差值不仅包括了衰减的偏差也包括散射不同带来的偏差。因此,利用双波段雷达功率谱数据经过小粒子选择计算受Mie散射影响小的粒子,用最小二乘法计算DWR(dual wavelength ratio)的变化率,反演液态水含量和液态水积分总量,将双波段雷达基数据和功率谱数据反演结果与微波辐射计的作对比,结果表明:(1)经过小粒子选择,去掉了双波段雷达的回波强度因散射不同带来的偏差。(2)在高度较低时双波段雷达基数据和功率谱数据经过小粒子选择反演的液态水含量有着较大区别。随着高度的增加,反演的液态水含量比较接近。(3)双波段雷达基数据和功率谱数据反演的液态水含量与微波辐射计进行定性分析,变化趋势能够达到较为一致,微波辐射计液态水含量较强的区域,两者反演的液态水含量也相应较大。(4)双波段雷达基数据和功率谱数据反演的液态水积分总量和微波辐射计的液态水积分总量随着时间的变化趋势较为一致,但双波段雷达功率谱数据总体程度小于基数据反演的液态水积分,双波段雷达基数据与功率谱数据反演的液态水积分总量总体小于微波辐射计的液态水积分总量值。
When a single-band radar uses the Z-LWC relationship to retrieve liquid water content,the content of liquid water retrieved by different precipitation types will vary greatly.Using dual-band radar echo intensity deviation to retrieve the liquid water content,the difference obtained by directly subtracting the dual-band radar base data echo intensity includes not only the deviation of attenuation but also the deviation caused by different scattering.Therefore,this paper uses the dual-band radar doppler spectrum data to calculate the particles that are less affected by Mie scattering through small particle selection,calculates the rate of change of DWR(dual wavelength ratio)using the least square method,and retrieves the liquid water content and total liquid water integral,the results of the dual-band radar base data and doppler spectrum data are compared with the microwave radiometer.The results show that:(1)After selecting small particles,the echo intensity of the dual-band radar is removed due to different scattering bias.(2)When the altitude is low,there is a big difference between the liquid water content of the dual-band radar base data and the doppler spectrum data after small particle selection.With the altitude increases,the retrieved liquid water content is closer.(3)The liquid water content retrieved from dual-band radar base data and doppler spectrum data is qualitatively analyzed with the microwave radiometer,and the change trend can be more consistent.In areas where the liquid water content is strong,the liquid water content retrieved by the dual-wavelength is correspondingly larger.(4)The total liquid water integration retrieved by the dual-band radar base data and doppler spectrum data and the total liquid water integration retrieved by the microwave radiometer the change trend of the quantity over time is relatively consistent,but the overall degree of the dual-band radar doppler spectrum data is less than the liquid water integration retrieved from the base data,and the total liquid water integrat
作者
邹琳
刘黎平
ZOU Lin;LIU Liping(College of Electronic Engineering,Chengdu University of Information Technology,Chengdu 601225,China;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Science,Beijing 100081,China)
出处
《成都信息工程大学学报》
2021年第2期129-137,共9页
Journal of Chengdu University of Information Technology
基金
国家自然科学基金资助项目(41875036)
关键词
双波段云雷达
液态水含量
回波强度偏差
小粒子
最小二乘法
微波辐射计
dual-wavelength cloud radar
liquid water content
echo strength deviation
small particles
least squares method
microwave radiometer
