Corona-producing ice clouds: a case study of a cold mid-latitude cirrus layer.
Corona-producing ice clouds: a case study of a cold mid-latitude cirrus layer.
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电晕产生的冰云：寒冷中纬度卷云层的案例研究。
DOI：
10.1364/ao.37.001477
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发表时间：
1998
期刊：
影响因子：
1.9
通讯作者：
M. Poellot
中科院分区：
文献类型：
--
作者：
K. Sassen;Gerald G. Mace;John Hallett;M. Poellot
1994年4月19日晚，在北方俄克拉荷马州的云和辐射试验台，用地面偏振激光雷达、毫米波雷达和飞机探测器研究了一个高（14.0公里）、冷（-71.0 ℃）的卷云。这种1-2公里深的云产生了罕见的卷云月晕，从而提供了一个现场测量成分的机会，这在以前只是根据激光雷达去偏振数据和简单的球体衍射理论假设的。在这种情况下，电晕环分析表明有效粒径为~22 μ m。各种原位数据证实了被动检索方法得出的近似冰颗粒大小，特别是在云顶附近，受影响的云样品显示简单的固体晶体。平流层起源的硫酸液滴的均匀冻结被认为是主导的冰粒子成核模式在产生日冕的卷云。据推测，这一过程导致了一种以前未被认识到的酸污染冰粒生长模式，这种小颗粒冷卷云可能是一种辐射独特的云。
A high (14.0-km), cold (-71.0 degrees C) cirrus cloud was studied by ground-based polarization lidar and millimeter radar and aircraft probes on the night of 19 April 1994 from the Cloud and Radiation Testbed site in northern Oklahoma. A rare cirrus cloud lunar corona was generated by this 1-2-km-deep cloud, thus providing an opportunity to measure the composition in situ, which had previously been assumed only on the basis of lidar depolarization data and simple diffraction theory for spheres. In this case, corona ring analysis indicated an effective particle diameter of ~22 mum. A variety of in situ data corroborates the approximate ice-particle size derived from the passive retrieval method, especially near the cloud top, where impacted cloud samples show simple solid crystals. The homogeneous freezing of sulfuric acid droplets of stratospheric origin is assumed to be the dominant ice-particle nucleation mode acting in corona-producing cirrus clouds. It is speculated that this process results in a previously unrecognized mode of acid-contaminated ice-particle growth and that such small-particle cold cirrus clouds are potentially a radiatively distinct type of cloud.