• Alena, T., J. Hallett, and C. P. R. Saunders, 1990: On the facet-skeletal transition of snow crystals: Experiments in high and low gravity. J. Cryst. Growth, 104, 539555.

    • Search Google Scholar
    • Export Citation
  • Anderson, B. J., and J. Hallett, 1979: Influence of environmental saturation and electric field on growth and evaporation of epitaxial ice crystals. J. Cryst. Growth, 46, 427444.

    • Search Google Scholar
    • Export Citation
  • Bailey, M., J. Hallett, D. Petersen, and W. Beasley, 2004: Laboratory investigation of positive discharges from ice crystals: Possible relevance to lightning initiation and ice multiplication. Proc. 14th Int. Conf. on Clouds and Precipitation, Vol. 2, Bologna, Italy, ICCP, 986–989.

  • Frank, F. C., 1982: Snow crystals. Contemp. Phys., 23, 322.

  • Griggs, D. J., and T. W. Choularton, 1983: Freezing modes of riming droplets with application to ice splinter production. Quart. J. Roy. Meteor. Soc., 109, 243253.

    • Search Google Scholar
    • Export Citation
  • Hallett, J., and B. J. Mason, 1958: The influence of temperature and supersaturation on the habit of ice crystals grown from the vapour. Proc. Roy. Soc. London, 247A, 440453.

    • Search Google Scholar
    • Export Citation
  • Hallett, J., and S. C. Mossop, 1974: Production of secondary ice particles during the riming process. Nature, 249, 2628.

  • Keller, V. W., and J. Hallett, 1982: Influence of air velocity on the habit of ice crystal growth from the vapor. J. Cryst. Growth, 60, 91106.

    • Search Google Scholar
    • Export Citation
  • Keller, V. W., C. V. McKnight, and J. Hallett, 1980: Growth of ice discs from the vapor and the mechanism of habit change of ice crystals. J. Cryst. Growth, 49, 458464.

    • Search Google Scholar
    • Export Citation
  • Knight, C. A., 1972: Another look at ice crystal growth habits. Trans. Amer. Geophys. Union, 53, 382.

  • Knight, C. A., 2005: An exploratory study of ice-cube spikes. J. Glaciol., 51, 191200.

  • Knight, C. A., and N. C. Knight, 1974: Drop freezing in clouds. J. Atmos. Sci., 31, 11741176.

  • Knight, C. A., and A. L. DeVries, 2009: Ice growth in supercooled solutions of a biological “antifreeze”, AFGP 1-5: An explanation in terms of adsorption rate for the concentration dependence of the freezing point. Phys. Chem. Chem. Phys., 11, 57495761.

    • Search Google Scholar
    • Export Citation
  • Kobayashi, T., 1961: The growth of snow crystals at low supersaturations. Philos. Mag., 6, 13631370.

  • Libbrecht, K. G., 2005: The physics of snow crystals. Rep. Prog. Phys., 68, 855895.

  • Libbrecht, K. G., and V. M. Tanusheva, 1998: Electrically induced morphological instabilities in free dendrite growth. Phys. Rev. Lett., 81, 176179.

    • Search Google Scholar
    • Export Citation
  • Libbrecht, K. G., and V. M. Tanusheva, 1999: Cloud chambers and crystal growth: Effects of electrically enhanced diffusion on dendrite formation from neutral molecules. Phys. Rev. E, 59, 32533261.

    • Search Google Scholar
    • Export Citation
  • Libbrecht, K. G., T. Crosby, and M. Swanson, 2002: Electrically enhanced free dendrite growth in polar and non-polar systems. J. Cryst. Growth, 240, 241254.

    • Search Google Scholar
    • Export Citation
  • Magono, C., and C. W. Lee, 1966: Meteorological classification of natural snow crystals. J. Fac. Sci. Hokkaido Univ., 2, 321335.

  • McKnight, C. V., and J. Hallett, 1978: X-ray topographic studies of dislocations in vapor-grown ice crystals. J. Glaciol., 21, 397407.

    • Search Google Scholar
    • Export Citation
  • Mizuno, Y., 1978: Studies of crystal imperfections in ice with reference to the growth process by the use of X-ray diffraction topography and divergent Laue method. J. Glaciol., 21, 409418.

    • Search Google Scholar
    • Export Citation
  • Mossop, S. C., 1976: Production of secondary ice particles during the growth of graupel by riming. Quart. J. Roy. Meteor. Soc., 102, 4557.

    • Search Google Scholar
    • Export Citation
  • Mossop, S. C., 1980: The mechanism of ice splinter production during riming. Geophys. Res. Lett., 7, 167169.

  • Mossop, S. C., 1985a: The origin and concentration of ice crystals in clouds. Bull. Amer. Meteor. Soc., 66, 264273.

  • Mossop, S. C., 1985b: Secondary ice particle production during rime growth: The effect of drop size distribution and rimer velocity. Quart. J. Roy. Meteor. Soc., 111, 11131124.

    • Search Google Scholar
    • Export Citation
  • Mossop, S. C., and J. Hallett, 1974: Ice crystal concentration in cumulus clouds: Influence of the drop spectrum. Science, 186, 632634.

    • Search Google Scholar
    • Export Citation
  • Nakaya, U., 1954: Snow Crystals, Natural and Artificial. Harvard University Press, 510 pp.

  • Nelson, J., and C. Knight, 1998: Snow crystal habit changes explained by layer nucleation. J. Atmos. Sci., 55, 14521465.

  • Shimizu, H., 1963: “Long prism” crystals observed in the precipitation in Antarctica. J. Meteor. Soc. Japan, 41, 305307.

  • Visagie, P. J., 1969: Pressures inside freezing water drops. J. Glaciol., 8, 301309.

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Ice Growth from the Vapor at −5°C

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  • 1 National Center for Atmospheric Research,* Boulder, Colorado
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Abstract

Results are summarized and illustrated from a long series of experiments on ice growth from the vapor, nearly all in a very small range of conditions: −5°C, slightly below liquid water saturation, with minimal environmental gradients and no imposed ventilation. The temperature was chosen because c-axis ice needles grow in a narrow temperature interval there, which coincides with the temperature at which the Hallett–Mossop ice multiplication process operates most effectively, and one may suspect that this coincidence is likely to be meaningful. The ice growth habit is poorly reproducible in these conditions, dictating many runs with little change. Growth as plates can persist for hours, and two distinct types of needle growth occur, called sheath needles and sharp needles. Both are distinct from thin columns in that they taper to a point, with no discernible basal face. Both deviate slightly from parallel to the c axis. Sharp needles have been reported before, but only as occurring with an applied high DC voltage. New crystal orientations nucleate occasionally at the tips of the sharp needles; this also has been seen before in the presence of strong electric fields. There appears to be an ice multiplication mechanism in these conditions that does not involve riming.

The National Center for Atmospheric Research is sponsored by the National Science Foundation.

Corresponding author address: Charles A. Knight, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307. E-mail: knightc@ucar.edu

Abstract

Results are summarized and illustrated from a long series of experiments on ice growth from the vapor, nearly all in a very small range of conditions: −5°C, slightly below liquid water saturation, with minimal environmental gradients and no imposed ventilation. The temperature was chosen because c-axis ice needles grow in a narrow temperature interval there, which coincides with the temperature at which the Hallett–Mossop ice multiplication process operates most effectively, and one may suspect that this coincidence is likely to be meaningful. The ice growth habit is poorly reproducible in these conditions, dictating many runs with little change. Growth as plates can persist for hours, and two distinct types of needle growth occur, called sheath needles and sharp needles. Both are distinct from thin columns in that they taper to a point, with no discernible basal face. Both deviate slightly from parallel to the c axis. Sharp needles have been reported before, but only as occurring with an applied high DC voltage. New crystal orientations nucleate occasionally at the tips of the sharp needles; this also has been seen before in the presence of strong electric fields. There appears to be an ice multiplication mechanism in these conditions that does not involve riming.

The National Center for Atmospheric Research is sponsored by the National Science Foundation.

Corresponding author address: Charles A. Knight, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307. E-mail: knightc@ucar.edu
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