Growth by Accretion in the Ice Phase

  1. Helmut Weickmann
  1. R. H. Douglas

Published Online: 18 MAR 2013

DOI: 10.1029/GM005p0264

Physics of Precipitation: Proceedings of the Cloud Physics Conference, Woods Hole, Massachusetts, June 3-5, 1959

Physics of Precipitation: Proceedings of the Cloud Physics Conference, Woods Hole, Massachusetts, June 3-5, 1959

How to Cite

Douglas, R. H. (1960) Growth by Accretion in the Ice Phase, in Physics of Precipitation: Proceedings of the Cloud Physics Conference, Woods Hole, Massachusetts, June 3-5, 1959 (ed H. Weickmann), American Geophysical Union, Washington D. C.. doi: 10.1029/GM005p0264

Author Information

  1. Meteorological Service of Canada, and Mcgill University,, Montreal, Canada

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1960

Book Series:

  1. Geophysical Monograph Series

Book Series Editors:

  1. Waldo E. Smith

ISBN Information

Print ISBN: 9780875900056

Online ISBN: 9781118668931

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Keywords:

  • Accretion process, ice phase;
  • Density of particle;
  • Growth calculations;
  • Growth of spherical ice particles;
  • Growth rates

Summary

The growth of spherical ice particles of various densities by sublimation and accretion is considered. The less dense the particle, the greater the mass it must achieve by sublimation before accretion becomes the dominant growth mechanism. Once this stage is achieved, however, growth rates of particles of the same mass are relatively insensitive to particle density, the cloud water content exercising the major control. With low water content (0.1 gm m−3) such as in stratiform clouds and in the dilute peripheral regions of cold Cumulus, the precipitation products are essentially sublimation elements rather than graupel. In four gm m−3 Cumulus, low-density graupel can grow to millimeter size within six minutes and to centimeter size within ten minutes, much denser particles requiring only a few minutes longer to reach the same sizes. These times are comparable with the observed elapsed times of about 15 min between the detection of the first radar echo and the first appearance of hail at the ground.