Use of polarization for cloud study
Use of polarization for cloud study
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DOI：
10.1117/12.283865
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发表时间：
1997-10
期刊：
影响因子：
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通讯作者：
P. Goloub;H. Chepfer;M. Herman;G. Brogniez;F. Parol
中科院分区：
文献类型：
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作者：
P. Goloub;H. Chepfer;M. Herman;G. Brogniez;F. Parol
POLDER已于1996年8月在日本的ADEOS平台上推出。由于它的多方向、多光谱和多极化能力，这种新的辐射计提供了关于云及其对短波范围内辐射的影响的有用信息。POLDER双向观测能力提供了以443、670和865 nm为中心的空间分辨率为7 KM×7 KM的三个光谱带中大范围散射角的偏振特征。这些原始特征可以获得一些关于云的热力学相，甚至关于粒子的云微物理的信息。云相识别是云研究的重要内容。冰晶对应于不同于液态水滴的物理过程和性质。在角度极高的空中观测中，液云液滴在140度附近的散射角度显示出彩虹的非常特殊的偏振特征。相反，根据理论研究和航空测量，各种晶体粒子的散射都表明，当粒子离开球形时，彩虹特征就消失了。本文给出了利用POLDER星载版本的偏振光进行云观测的初步结果，重点介绍了云的位相检测和微物理反演。
POLDER has been launched on the Japanese ADEOS platform in August 1996. Due to its multi-directional, multispectral and multi-polarization capabilities, this new radiometer gives useful information on the clouds and on their influence on the radiation in the shortwave range. The POLDER bidirectional observation capability provides the polarization signatures within a large range of scattering angles in three spectral bands centered on 443, 670 and 865 nm with a spatial resolution of 7km X 7km. These original features allow to obtain some information both on cloud thermodynamic phase and even on the cloud microphysic of particles. Cloud phase recognition is important for cloud studies. Ice crystals correspond to physical process and properties that differ from those of liquid water drops. The angular POLDER airborne observations, liquid cloud droplets exhibit the very specific polarization features of the rainbow for scattering angels near 140 degrees. Conversely, according to theoretical studies and also to airborne measurements, scattering by various crystalline particles all show that the rainbow characteristics disappear as soon as the particles depart from the spherical shape. In the paper, preliminary results about cloud observations using polarized light measured by the spaceborne version of POLDER are presented, with emphasis on cloud phase detection and microphysic retrieval.