Laboratory Measurements of Light Scattering by Single Levitated Ice Crystals

Autor: N.J. Bacon, Brian D. Swanson
Rok vydání: 2000
Předmět:
Zdroj: Journal of the Atmospheric Sciences. 57:2094-2104
ISSN: 1520-0469
0022-4928
DOI: 10.1175/1520-0469(2000)057<2094:lmolsb>2.0.co;2
Popis: The authors have measured the differential light-scattering cross sections and phase functions of single vapor-grown hexagonal ice particles levitated in an electrodynamic balance. The ice particles, grown at temperatures −5° > T > −10°C, were typically ≈50 μm in diameter and tended to orient with the c axis either nearly vertical (parallel to the scattering plane normal) or horizontal (in the scattering plane). Helium–neon laser light scattered by a levitated crystal was collected in the angular ranges 20°–65° and 115°–160° with a 1024-element linear photodiode array with an angular resolution of about 0.05°. The particle size and orientation were measured a few seconds before and after the scattering measurements with top- and side-view video telemicroscopes. Three basic features are found in the scattering from vertically aligned crystals: (i) a strong “halo” peak between about 21° and 35°, (ii) a secondary peak with ripple structure between about 30° and 70°, and (iii) a weaker peak in the ba...
Databáze: OpenAIRE