Ice crystal habits from cloud chamber studies obtained by in-line holographic microscopy related to depolarization measurements.
Ice crystal habits from cloud chamber studies obtained by in-line holographic microscopy related to depolarization measurements.
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DOI：
10.1364/ao.48.005811
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发表时间：
2009-10
期刊：
影响因子：
1.9
通讯作者：
P. Amsler;O. Stetzer;M. Schnaiter;E. Hesse;S. Benz;O. Moehler;U. Lohmann
中科院分区：
文献类型：
--
作者：
P. Amsler;O. Stetzer;M. Schnaiter;E. Hesse;S. Benz;O. Moehler;U. Lohmann
我们用新开发的全息显微镜显微物体全息成像仪(HOLIMO)研究了AIDA小室的水流星习性。混合相云实验中冰晶和水滴的大小和习性与相对于冰的相对湿度(RH(冰))、温度(T)和实验时间有关。这项实验是用过冷水滴启动的。结果发现，冰晶的最大粒径范围为2到118微米(平均尺寸为19微米)，其中63%的冰晶具有规律性。观察到的粒子习性与对给定的RH(冰)和T的预测相匹配，从这片云中出现了两种不同的生长模式。第一个出现在注水过程中，主要显示光学颗粒尺寸在5至250微米范围内。第二个模式在第一个模式的粒子刚刚脱落之后，增长到5到63微米的大小。结果表明，HOLIMO测量得到的最大长度与厚度的长径比chi从2增加到20，对应的线性退极化比从0.1减小到0.04，这是由退偏测量独立获得的。
We investigate hydrometeor habits at the AIDA chamber with a newly developed in-line holographic microscope HOLographic Imager for Microscopic Objects (HOLIMO). Sizes and habits of ice crystals and droplets in a mixed-phase cloud experiment are related to relative humidity with respect to ice (RH(ice)), temperature (T), and experiment time. This experiment is initiated with supercooled water drops. As a result, ice crystals within a maximum particle diameter size range of 2 to 118 microm (average size of 19 microm) are detected and 63% of them reveal regular habits. The observed particle habits match those predicted for a given RH(ice) and T. Two different growth modes emerge from this cloud. The first one appears during water injection and reveals mainly optical particle sizes in the range of 5 to 250 microm. The second mode grows to sizes of 5 to 63 microm, just after the particles of the first one fall out. It is found that an increasing aspect ratio chi of maximum length over thickness from 2 to 20 as obtained by HOLIMO corresponds to a decreasing linear depolarization ratio from 0.1 to 0.04, as independently obtained by depolarization measurements.