吴举秀,窦芳丽,安大伟,顾瑜,周青,刘伟. 2019. 94/220 GHz星载雷达双波长比对非球形冰晶云参数敏感性分析[J]. 气象学报, 77(3):529-540, doi:10.11676/qxxb2019.016
94/220 GHz星载雷达双波长比对非球形冰晶云参数敏感性分析
Sensitivity of dual wavelength reflectivity ratio of 94/220 GHz space-borne radar to cloud parameters with non-spherical ice crystals
投稿时间:2018-03-16  修订日期:2018-07-24
DOI:10.11676/qxxb2019.016
中文关键词:  非球形冰晶  星载94/220GHz云雷达  双波长(反射率)比  冰晶谱参数
英文关键词:Non-spherical ice particles  94/220 GHz space-borne cloud radars  Dual wavelength reflectivity ratio  Parameters of ice particles size distribution
基金项目:国防科工局“十二五”项目“太赫兹测云成像技术研究”、科技部公益性行业(气象)科研专项(GYHY201406033)、国家自然科学基金项目(41305031)、江苏高校优势学科建设工程资助项目(PAPD)。
作者单位
吴举秀 山东省气象局大气探测技术保障中心, 济南, 250031 
窦芳丽 国家卫星气象中心, 北京, 100081 
安大伟 国家卫星气象中心, 北京, 100081 
顾瑜 青岛市气象局, 山东青岛, 266003 
周青 中国气象局气象探测中心, 北京, 100081 
刘伟 山东省气象局大气探测技术保障中心, 济南, 250031 
摘要点击次数: 213
全文下载次数: 174
中文摘要:
      利用不同形状冰晶的散射特性,获得了非球形冰晶云的94/220 GHz测云雷达双波长比,探讨了非球形冰晶云的双波长比与云内微物理参数的关系,分析了衰减前后的星载雷达反射率因子及双波长比的垂直廓线。结果表明:(1)双波长比可以反映小到0.1 mm中值尺度的冰粒子,对粒子总数、谱的形状参数不敏感,对粒子大小、形状、云衰减较敏感。(2)雷达灵敏度一定时,星载雷达可测云厚与雷达波长、冰含水量(IWC)的垂直分布、云厚及衰减有关;没有进行衰减订正时,双波长比和衰减有关,冰含水量越大,波长越短,衰减越大,双波长比最大值与可探测云厚有关。两部雷达可探测冰含水量为0.001—0.1 g/m3、厚2 km的冰云;当云厚5 km、冰含水量垂直分布在0.001—0.2 g/m3时,云厚的94%基本可以被220 GHz云雷达探测到。(3)如果两部雷达气象方程中用水的介电因子,测量回波强度应进行介电因子的订正后再计算双波长比。
英文摘要:
      The dual wavelength reflectivity ratio (DWR) of 94/220 GHz radar to non-spherical ice clouds was obtained based on the scattering characteristics of ice crystals with different shapes, and the relationships between the DWR and the cloud parameters were analyzed. The vertical profiles of the unattenuated and attenuated radar reflectivity factors and DWR were studied. The results are as follows. (1) The DWR is sensitive to the size and shape of particles, the attenuation from clouds and the median maximum dimension of the particles size distribution (PSD) that can even be as small as 0.1 mm, but insensitive to the particle concentration and shape parameters of the PSD. (2) When the sensitivity of radar receiver is certain, the ability of space-borne radars to detect cloud thickness depends on the wavelengths of radars, the vertical profiles of the ice water content (IWC), the thickness of the cloud and the attenuation. In the condition of no attenuation correction, the DWR related to the attenuation and the maximum is determined by the detected cloud thickness, while higher IWC and shorter wavelength correspond to larger attenuation. As a result, the two radars can detect the ice clouds with IWC=0.001-0.1 g/m3 and thickness of 2 km. Furthermore, 94% of the cloud thickness can be explored for the ice clouds with IWC=0.001-0.2 g/m3 and the thickness of 5 km. (3) When the dielectric factors of water are using in the two radars' meteorological equations, the DWR can only be obtained after directly detected echo intensity is corrected.
HTML   查看全文   查看/发表评论  下载PDF阅读器
分享按钮