The Mueller matrix (<i>M</i>) corresponding to the phase matrix in the backscattering region (scattering angles ranging from 175° to 180°) is investigated for light scattering at a 0.532-μm wavelength by hexagonal ice crystals, ice spheres, and water droplets. For hexagonal ice crystals we assume three aspect ratios (plates, compact columns, and columns). It is shown that the contour patterns of the backscattering Mueller matrix elements other than <i>M</i><sub>11</sub>, <i>M</i><sub>44</sub>, <i>M</i><sub>14</sub>, and <i>M</i><sub>41</sub> depend on particle geometry; <i>M</i><sub>22</sub> and <i>M</i><sub>33</sub> are particularly sensitive to the aspect ratio of ice crystals. The Mueller matrix for spherical ice particles is different from those for nonspherical ice particles. In addition to discriminating between spherical and nonspherical particles, the Mueller matrix may offer some insight as to cloud thermodynamic phase. The contour patterns for large ice spheres with an effective size of 100 μm are substantially different from those associated with small water droplets with an effective size of 4 μm.
© 2003 Optical Society of America
(010.1310) Atmospheric and oceanic optics : Atmospheric scattering
(290.1090) Scattering : Aerosol and cloud effects
(290.1350) Scattering : Backscattering
(290.5850) Scattering : Scattering, particles
Ping Yang, Heli Wei, George W. Kattawar, Yong X. Hu, David M. Winker, Chris A. Hostetler, and Bryan A. Baum, "Sensitivity of the Backscattering Mueller Matrix to Particle Shape and Thermodynamic Phase," Appl. Opt. 42, 4389-4395 (2003)