Editorial Type:
Article
Article Type:
Research Article

Aircraft Observations of Ice Crystal Evolution in an Altostratus Cloud

Paul R. Field Meteorological Research Flight, DERA, Farnborough, Hampshire, United Kingdom

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Print Publication:
01 Jun 1999
DOI:
https://doi.org/10.1175/1520-0469(1999)056<1925:AOOICE>2.0.CO;2
Page(s):
1925–1941
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Abstract

Observations from a Lagrangian spiral descent within altostratus cloud associated with a cold front were used to study the evolution of ice particle spectra by following populations of ice crystals as they fell through the cloud. The flight track was corrected for wind effects and was divided into distinct regions for spatial comparison of ice particle spectra. Analysis of size spectra for particles larger than 800 μm revealed heterogeneity on horizontal scales of 5 km in average particle diameter and concentration. In the temperature range −40° to −20°C the ice crystal evolution was dominated by diffusional growth, although observations of the evolution of the bimodal size spectra suggested that aggregation was occurring. Between −20° and −10°C aggregation dominated evolution.

Corresponding author address: Dr. Paul R. Field, Meteorological Research Flight, Building Y46 DERA, Farnborough, Hampshire GU14 0LX, United Kingdom.

Abstract

Observations from a Lagrangian spiral descent within altostratus cloud associated with a cold front were used to study the evolution of ice particle spectra by following populations of ice crystals as they fell through the cloud. The flight track was corrected for wind effects and was divided into distinct regions for spatial comparison of ice particle spectra. Analysis of size spectra for particles larger than 800 μm revealed heterogeneity on horizontal scales of 5 km in average particle diameter and concentration. In the temperature range −40° to −20°C the ice crystal evolution was dominated by diffusional growth, although observations of the evolution of the bimodal size spectra suggested that aggregation was occurring. Between −20° and −10°C aggregation dominated evolution.

Corresponding author address: Dr. Paul R. Field, Meteorological Research Flight, Building Y46 DERA, Farnborough, Hampshire GU14 0LX, United Kingdom.

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  • Arnott, W. P., Y. Dong, J. Hallet, and M. R. Poellot, 1994: Role of small ice crystals in radiative properties of cirrus: A case study, FIRE II, November 22, 1991. J. Geophys. Res.,99 (D1), 1371–1381.

  • Francis, P. N., 1995: Some aircraft observations of the scattering properties of ice crystals. J. Atmos. Sci.,52, 1142–1154.

  • ——, A Jones, R. W. Saunders, K. P. Shine, A. Slingo, and Z. Sun, 1994: An observational and theoretical study of the radiative properties of cirrus: Some results from ICE’89. Quart. J. Roy Meteor. Soc.,120, 809–848.

  • Gordon, G. L., and J. D. Marwitz, 1986: Hydrometeor evolution in rainbands over the California valley. J. Atmos. Sci.,43, 1087–1100.

  • Gunn, K. L. S., and J. S. Marshall, 1958: The distribution with size of aggregate snowflakes. J. Meteor.,15, 452–461.

  • Herzegh, P. H., and P. V. Hobbs, 1985: Size spectra of ice particles in frontal clouds: Correlations between spectrum shape and cloud conditions. Quart. J. Roy. Meteor. Soc.,111, 463–477.

  • Heymsfield, A. J., 1975: Cirrus uncinus generating cells and the evolution of cirriform clouds. Part I: Aircraft observations of the growth of the ice phase. J. Atmos. Sci.,32, 799–808.

  • ——, 1977: Precipitation development in stratiform ice clouds: A microphysical and dynamical study. J. Atmos. Sci.,34, 367–381.

  • ——, and L. M. Miloshevich, 1995: Relative humidity and temperature influences on cirrus formation and evolution: Observations from wave clouds and FIRE II. J. Atmos. Sci.,52, 4302–4326.

  • Houze, R. A., Jr., J. D. Locatelli, and P. V. Hobbs, 1976: Dynamics and cloud microphysics of the rainbands in an occluded frontal system. J. Atmos. Sci.,33, 1921–1936.

  • ——, P. V. Hobbs, P. H. Herzergh, and D. B. Parsons, 1979: Size distributions of precipitation particles in frontal clouds. J. Atmos. Sci.,36, 156–162.

  • Kajikawa, M., and A. J. Heymsfield, 1989: Aggregation of ice crystals in cirrus. J. Atmos. Sci.,46, 3108–3121.

  • Knollenberg, R. G., 1970: The optical array: An alternative to scattering or extinction for airborne particle size determination. J. Appl. Meteor.,9, 86–103.

  • Lo, K., and R. E. Passarelli, 1982: The growth of snow in winter storms: An airborne observational study. J. Atmos. Sci.,39, 697–706.

  • Mitchell, D. L., 1988: Evolution of snow-size spectra in cyclonic storms. Part I: Snow growth by vapor deposition and aggregation. J. Atmos. Sci.,45, 3431–3451.

  • ——, 1991: Evolution of snow-size spectra in cyclonic storms. Part II: Deviations from the exponential form. J. Atmos. Sci.,48, 1885–1899.

  • ——, S. K. Chai, Y. Liu, A. J. Heymsfield, and Y. Dong, 1996: Modeling cirrus clouds. Part I: Treatment of bimodal size spectra and case study analysis. J. Atmos. Sci.,53, 2952–2966.

  • Moss, S. J., P. R. A. Brown, D. W. Johnson, D. R. Lauchlin, G. M. Martin, M. A. Pickering, and A. Spice, 1993: Cloud microphysics measurements on the MRF C-130: Working group report. MRF Tech. Note 12, Meteorological Research Flight, Farnborough, Hampshire, United Kingdom, 147 pp. [Available from Meteorological Research Flight, Building Y46 DERA, Farnborough, Hampshire GU14 0LX, United Kingdom.].

  • Ohtake, T., 1970: Factors affecting the size distribution of raindrops and snowflakes. J. Atmos. Sci.,27, 804–813.

  • Passarelli, R. E., 1978a: An approximate analytical model of the vapor deposition and aggregation growth of snowflakes. J. Atmos. Sci.,35, 118–124.

  • ——, 1978b: Theoretical and observational study of snow-size spectra and snowflake aggregation efficencies. J. Atmos. Sci.,35, 882–889.

  • Platt, C. M. R., 1997: A parameterization of the visible extinction coefficient of ice clouds in terms of the ice/water content. J. Atmos. Sci.,54, 2083–2098.

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