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<br />computed from droplet and crystal single scattering and an analytical treatment of droplet double <br />scattering. Water cloud results reveal the expected increases in linear depolarization ratios (0) with <br />increasing lidar field of view and distance to cloud, but also show that depolarization is a function of <br />cloud liquid water content, which depends primarily on temperature. Ice crystals modulate mixed-phase <br />cloud liquid water contents through water vapor competition effects. thereby affecting multiple scattering <br />o values as functions of updraft velocity, temperature, and crystal size and concentration. Although the <br />minimum 0 at cloud base increases with increasing ice content, the peak measurable 0 in the cloud <br />decreases. Comparison with field data demonstrate that this modeling approach is a valuable <br />supplement to cloud measurements. <br /> <br />Sassen, K., 1991: The lidar depolarization technique for cloud and aerosol research. Preprints, 71st Annual <br />Meeting of the American Meteorological Society, New Orleans, LA. January 14-18, 1991. American <br />Meteorological Society, Boston, MA, 448-451. <br /> <br />No abstract. <br /> <br />Sassen, K.. 1991: The polarization lidar technique for cloud research: A review and current assessment. <br />Bulletin of the American Meteorological Society, 72:1848-1866. <br /> <br />The development of the polarization lidar field over the past two decades is reviewed. and the current <br />cloud research capabilities and limitations are evaluated. Relying on fundamental scattering principles <br />governing the interaction of polarized laser light with distinctly shaped hydrometers, this remote sensing <br />technique has contributed to our knowledge of the composition and structure of a variety of cloud types. <br />For example, polarization lidar is a key component of current climate research programs to characterize <br />the properties of cirrus clouds, and is an integral part of multiple remote sensor studies of mixed-phase <br />cloud systems, such as winter mountain storms. Although unambiguous cloud phase discrimination and <br />the identification of some ice particle types and orientations are demonstrated capabilities. recent <br />theoretical approaches involving ice crystal ray-tracing and cloud microphysical model simulations are <br />promising to increase the utility of the technique. New results simulating the single and multiple <br />scattering properties of precipitating mixed-phase clouds are given for illustration of such methods. <br /> <br />Sassen, K., A. W. Huggins, A. B. Long, J. B. Snider, and R.,J. Meitin, 1990: Investigations of a winter <br />mountain storm in Utah. Part II: Mesoscale structure, supercooled liquid water development, and <br />precipitation processes. Journal of the Atmospheric Sciences, 47:1323-1350. <br /> <br />A comprehensive analysis of a deep winter storm system during its passage over the Tushar Mountains <br />of southwestern Utah is reported. The case study, drawn from the 1985 Utah/NOAA cooperative <br />weather modification experiment, is divided into descriptions of the synoptic and kinematic properties in <br />Part I, and storm structure and composition here in Part II. In future parts of this series, the turbulence <br />structure and indicated cloud seeding potential will be evaluated. The analysis presented here in Part II <br />focuses on multiple remote sensor and surface microphysical observations collected from a midbarrier <br />(2.57 km MSL) field site. The collocated remote sensors were a dual-channel microwave radiometer, a <br />polarization lidar, and a Ka-band Doppler radar. These data are supplemented by upwind, valley-based <br />C-band Doppler radar observations, which provided a considerably larger-scale view of the storm. <br /> <br />In general, storm properties above the barrier were either dominated by barrier-level orographic clouds <br />or propagating mesoscale cloud systems. The orographic cloud component consisted of weakly (_30 to <br />-100C) supercooled liquid water (SL W) clouds in the form of an extended barrier-wide cap cloud that <br />contained localized SL W concentrations. The spatial SL W distribution was linked to topographical <br />features surrounding the midbarrier site, such as abrupt terrain rises and nearby ridges. This orographic <br />cloud contributed to precipitation primarily through the riming of particles sedimenting from aloft. and <br /> <br />66 <br />