Abstract
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 (RHice), 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 μm (average size of 19 μm) are detected and 63% of them reveal regular habits. The observed particle habits match those predicted for a given RHice 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 μm. The second mode grows to sizes of 5 to 63 μm, just after the particles of the first one fall out. It is found that an increasing aspect ratio χ 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.
Original language | English |
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Pages (from-to) | 5811-5822 |
Journal | Appl. Opt |
Volume | 48 |
Issue number | 30 |
DOIs | |
Publication status | Published - 2009 |