Radar Scattering from Ice Aggregates Using the Horizontally Aligned Oblate Spheroid Approximation
Radar Scattering from Ice Aggregates Using the Horizontally Aligned Oblate Spheroid Approximation
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DOI：
10.1175/jamc-d-11-074.1
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发表时间：
2012-03
影响因子：
3
通讯作者：
Robin J. Hogan;L. Tian;P. R. A. Brown;Christopher D. Westbrook;A. Heymsfield;J. Eastment
中科院分区：
文献类型：
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作者：
Robin J. Hogan;L. Tian;P. R. A. Brown;Christopher D. Westbrook;A. Heymsfield;J. Eastment
摘要假设冰粒质量与尺寸之间的关系在冰云雷达检索中非常重要，但对于毫米波雷达来说，形状和首选方向也很重要。在本文中，作者首先考察了这样一个事实的后果，即广泛使用的“布朗和弗朗西斯”质量尺寸关系经常被应用于飞机观测到的最大粒子尺寸，而不是最初由布朗和弗朗西斯使用的粒子尺寸在两个正交方向上的平均值Dmean。粒子图像的分析表明Dmax≃1.25Dmean，因此，对于具有这种质量-大小关系的云，结果是冰含水量高估了53%左右，瑞利散射雷达反射系数高估了3.7 dB。同时进行的雷达和飞机测量表明，使用这种质量-尺寸关系与Dmean在反射率因子上有更好的一致性。然后，作者研究了……
AbstractThe assumed relationship between ice particle mass and size is profoundly important in radar retrievals of ice clouds, but, for millimeter-wave radars, shape and preferred orientation are important as well. In this paper the authors first examine the consequences of the fact that the widely used “Brown and Francis” mass–size relationship has often been applied to maximum particle dimension observed by aircraft Dmax rather than to the mean of the particle dimensions in two orthogonal directions Dmean, which was originally used by Brown and Francis. Analysis of particle images reveals that Dmax ≃ 1.25Dmean, and therefore, for clouds for which this mass–size relationship holds, the consequences are overestimates of ice water content by around 53% and of Rayleigh-scattering radar reflectivity factor by 3.7 dB. Simultaneous radar and aircraft measurements demonstrate that much better agreement in reflectivity factor is provided by using this mass–size relationship with Dmean. The authors then examine t...