Inferring Fall Attitudes of Pristine Dendritic Crystals from Polarimetric Radar Data
Inferring Fall Attitudes of Pristine Dendritic Crystals from Polarimetric Radar Data
复制标题
从偏振雷达数据推断原始树枝状晶体的坠落姿态
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
I. Djalalova
中科院分区：
文献类型：
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作者：
S. Matrosov;R. Reinking;I. Djalalova
摘要单一的原始平面冰晶在下落时，会围绕其优先的水平方向出现一些颤动。本研究提出了估计颤振和分析的原始树枝状晶体的偏振敏捷Ka波段云雷达观察到的主要下降的态度。观测是在山的斜坡上的弱降水冬季云。华盛顿，新罕布什尔州。该雷达可测量标准水平-垂直极化基（HLDR）和倾斜45°-135°极化基（SLDR）的线退极化比。HLDR和SLDR都依赖于晶体形状。HLDR也表现出强烈的依赖于晶体取向，而SLDR仅弱依赖于取向。SLDR和HLDR对形状和取向效应的不同敏感性被解释为估计晶体的角颤振。一个简单的解析表达式推导出的标准偏差的角颤振作为一个函数的HLDR到SLDR比假设p…
Abstract Single pristine planar ice crystals exhibit some flutter around their preferential horizontal orientation as they fall. This study presents estimates of flutter and analyzes predominant fall attitudes of pristine dendritic crystals observed with a polarization agile Ka-band cloud radar. The observations were made in weakly precipitating winter clouds on slopes of Mt. Washington, New Hampshire. The radar is capable of measuring the linear depolarization ratios in the standard horizontal–vertical polarization basis (HLDR) and the slant 45°–135° polarization basis (SLDR). Both HLDR and SLDR depend on crystal shape. HLDR also exhibits a strong dependence on crystal orientation, while SLDR depends only weakly on orientation. The different sensitivities of SLDR and HLDR to the shape and orientation effects are interpreted to estimate the angular flutter of crystals. A simple analytical expression is derived for the standard deviation of angular flutter as a function of the HLDR to SLDR ratio assuming p...