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Robert S. Schrom and Matthew R. Kumjian

. 2013 ), thereby determining the change in volume during the time step. This deposition density roughly approximates the sparse distribution of branches and subbranches during branched planar crystal growth; ρ at any stage of growth is simply the mass of the particle divided by its volume. The first component of a radar forward model maps the physical properties of a given ice particle to scattering properties. These scattering properties are calculated using two general methods: detailed

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Robert S. Schrom and Matthew R. Kumjian

below that of solid ice. This reduced density approximates the complex structure of pristine ice crystals and aggregates as a random distribution of mass within the particle’s bounding region. Therefore, in scattering calculations, ice particles with aspect ratios < 1, such as platelike crystals and aggregates, are modeled as oblate spheroids, and ice particles with aspect ratios > 1, such as columns and conical graupel, are modeled as prolate spheroids. Aspect ratio defined herein is the ratio of

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Mariko Oue, Matthew R. Kumjian, Yinghui Lu, Johannes Verlinde, Kultegin Aydin, and Eugene E. Clothiaux

). Recently developed numerical models that are capable of describing particle growth with diverse sizes, aspect ratios, and densities in such mixed-phase clouds (e.g., Harrington et al. 2013 ; Sulia et al. 2013 , 2014 ) require validation with observations. Polarimetric radar observables offer the capability of identification of hydrometeor species ( Hall et al. 1984 ; Straka and Zrnić 1993 ; Vivekanandan et al. 1999 ; and many others), including ice hydrometeors such as pristine crystal habits (e

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R. Paul Lawson, Brad A. Baker, Patrick Zmarzly, Darren O’Connor, Qixu Mo, Jean-Francois Gayet, and Valery Shcherbakov

1. Introduction SPEC, Inc., collected unique measurements of the size, shape, and concentration of over 900 000 ice crystals at the South Pole Station (SPS) from 1 to 8 February 2001. In 2001, SPEC operated two cloud particle imagers (CPIs) ( Lawson et al. 2001 ), and in February 2002 measurements from a polar nephelometer (PN) ( Gayet et al. 1997 ) that measures scattering phase function were added. The surface temperature during the period of observation reported here, 1–8 February 2001

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Kwo-Sen Kuo, William S. Olson, Benjamin T. Johnson, Mircea Grecu, Lin Tian, Thomas L. Clune, Bruce H. van Aartsen, Andrew J. Heymsfield, Liang Liao, and Robert Meneghini

properties of ice. Third, the relationship between particle number concentrations and gross particle size (or mass) must be specified for the purpose of computing the bulk scattering properties of snow particle polydispersions. In previous studies of the scattering properties of ice particles, particle geometries that are based upon the habits of individual pristine crystals (e.g., Tang and Aydin 1995 ; Liu 2004 ; Kim 2006 ; Hong 2007 ; Weinman and Kim 2007 ; Botta et al. 2013 ; Lu et al. 2014

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C. P. R. Saunders and N. M. A. Wahab

.qF. PTEMBElt 1973 C. P. R. S A U N 1) E P, S A N D N. M . A. \V A It A B 1035The Replication of Ice Crystals C. P. R. SAUNDERS AND N. M. A. WAttABPhysics Dept., Institute of Science and .Technology, University oJ Manchesler, England(Manuscript received 13 February 1973, in revised form 4 May 1973)ABSTRACT During the replication of ice crystals by conventional methods the crystals both grow and flocculate; thiscan lead to erroneous

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Takeshi Ohtake and Rudolf G. Suchannek

AVmL1970 TAKESHI OHTAKE AND RUDOLF G. SUCHANNEK 289Electric Properties of Ice Fog Crystals TAKESHI OttTAKE1 AND RUDOL~ G. S~JCX-X~NNEXGeophysical Institute, University of Alaska, College, Alaska(Manuscript received 28 April 1969, in revised form 8 December 1969)ABSTRACT Electric properties of ice fog crystals were studied using uniform and nonuniform electric-fields. It wasobserved that natural and artificial

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Steven J. Cooper and Timothy J. Garrett

1. Introduction Many field campaigns and satellite missions have been designed partly in attempt to gain a more accurate characterization of cirrus clouds. For example, the Cirrus Regional Study of Tropical Anvils and Cirrus Layers–Florida Area Cirrus Experiment (CRYSTAL-FACE), WB-57 Midlatitude Cirrus Cloud Experiment (WB57 MidCiX), and the Tropical Composition, Cloud, and Climate Coupling (TC4) experiment have pursued quantification of these ice clouds through the combination of in situ

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J. C. Hubbert, S. M. Ellis, W.-Y. Chang, and Y.-C. Liou

(H polarization), thereby causing bias in the SHV polarimetric variables. The two primary mechanisms that cause cross coupling are 1) antenna polarization errors ( McCormick and Hendry 1975 ; Hubbert et al. 2010a ) and 2) forward scatter through a medium of precipitation particles that have a significant nonzero mean canting angle, relative to the horizontal direction in the radar plane of polarization. One such medium is ice crystals that are canted because of an electric field ( Hendry and

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C. M. R. Platt

482 JOURNAL OF APPLIED METEOROLOGY VOLUME I7Lidar Backscatter from Horizontal Ice Crystal Plates C. M. R. PLATT~Cooperative lnsti~e for Research in Environmental S~iences, Uni~s~y of Co~r~/NOAA, B~, Colo. ~0300 (M~pt r~eived 7 Nov~ber 1977, in ~ fo~ 4 Janua~ 1978)ABSTRACT Some unusual lidar returns from an altostratus cloud are interpreted in terms of reflections

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