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Austin W. Hogan

246 JOURNAL OF APPLIED METEOROLOGY Vo~vsM~, 14NOTES AND CORRESPONDENCESummer Ice Crystal Precipitation at the South Pole AUSTIN W. HOGANAtmospheric Sciences Research Center, State University of New York at Albany, Scotia, iV. Y. 12302 13 May 1974 and 19 August 1974ABSTRACT Ice crystal precipitation was observed and the crystals replicated, at the South Pole during Januaryand

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Larry Vardiman

2168 JOURNAL OF THE ATMOSPHERIC SCIENCES VOL~JME35The Generation of Secondary Ice Particles in Clouds by Crystal-Crystal CollisionLARRY VARDIMAN1 Colorado Stat~ Ugi~rsity, Fort Collin% CO 80521(Manuscript received 6 June 1977, in final form 7 August 1978)ABSTRACT The number of fragments generated by crystal collisions in a cloud is a product of the number of fragmentsproduced per collision and the

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T. E. Hoffer and J. A. Warburton

1068 JOURNAL. OF THE ATMOSPHERIC SCIENCES VO~.U~E27Observations of Diffusional Ice Crystal Growth in Clouds T. E. HottER AND J. A. WARtlURTON Uni*ersity of Nevada System, Desert Research Institute, Reno(Manuscript received 2 June 1969, in revised form 9 January 1970)ABSTRACT The observed size of ice crystals obtained by sampling in Formvar is compared to the theoretical size anice crystal should attain when

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J. Hallett and C. P. R. Saunders

June 1979) , ABSTRACT Laboratory studies of rime growth on a moving rod under conditions of secondary ice crystalproduction show that the rod acquires a positive charge, equivalent to charge associated wihh each ejectedparticle of 5 x 10-4C. Ice crystals produced by seeding also impart a positive charge to the rime,equivalent to a charge per particle of 5 x 10-~6C. As the water vapor supply is cut off, the chargesign reverses. The results suggest

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Von P. Walden, Stephen G. Warren, and Elizabeth Tuttle

Introduction Ice crystals are nearly always present in the atmospheric boundary layer over the Antarctic Plateau. They interact with both solar and infrared radiation and, therefore, affect the planetary energy budget. Regional and general circulation models are sensitive to the shapes and sizes of ice crystals and water droplets specified for antarctic clouds ( Lubin et al. 1998 ). It has been difficult to retrieve properties of clouds over snow using satellite instruments, such as the

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Pao K. Wang and Wusheng Ji

1. Introduction Any quantitative investigation of the formation of clouds and precipitation cannot avoid dealing with the complicated motion of particles such as cloud droplets, raindrops, ice crystals, graupel, and hailstones. These particles move in a viscous medium, the air, and thus create complicated flow fields around themselves. These fields have important effects on the growth of the particles themselves. For example, due to the existence of these flow fields, the collision efficiencies

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A. J. Heymsfield and C. D. Westbrook

1. Introduction The sedimentation rates of ice crystals and snowflakes remain poorly characterized at present. Analytical solutions for the terminal velocity υ t of natural ice particles as they fall through the air have not been forthcoming because of their nonspherical shape and the range of flow regimes that they span. Empirical formulas based on experimental data and approximate theory are therefore required to predict how fast an ice particle with a given shape, size, and mass will fall

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Paul R. Field, Andrew J. Heymsfield, and Aaron Bansemer

in terms of the moments of an arbitrary PSD (e.g., Zawadzki et al. 2000 ; Thompson et al. 2007, manuscript submitted to Mon. Wea. Rev. ) provided that the physical attributes (e.g., mass, fall speed) of ice crystal aggregates (snow) are written as power laws of the particle dimension, as is commonly done. Two-moment schemes for snow are now being introduced (e.g., Ferrier 1994 ; Morrison et al. 2005 ; Milbrandt and Yau 2005 ; Seifert and Beheng 2006 ) that predict both IWC and number

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Choji Magono, Shin-Ichi Fujita, and Takashi Taniguchi

DECEMBER 1979 MAGONO, FUJITA AND TANIGUCHI 2495Unusual Types of Single Ice Crystals Originating from Frozen C[loud DropletsCHOJI MAGONO, SHIN-ICHI FUJITA1 AND TAKASHI TANIGUCHIDepartment of Geophysics, Hokkaido University, Sapporo, Japan(Manuscript received 8 May 1979, in final form 31 July 1979)ABSTRACT Laboratory experiments were conducted to study the formation process of unusual types of ice crystals

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Motoi Kumai and Karl E. Francis

474 JOURNAL OF TIlE ATMOSPHERIC SCIENCES VOLUMe 19Nuclei in Snow and Ice Crystals on the Greenland Ice Cap under l~latural and Artificially Stimulated Conditions~ Mo~o~ Ku~_~~ The University of Chicago AND KARL E. FRANCISaU. S. Army Cold Regions Research and Engineering Laboratory(Manuscript received 1 June 1962, in revised form 23 July 1962,)ABSTRACT Natural snow crystals and

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