• Anderson, T. L., R. J. Charlson, and D. S. Covert, 1993: Calibration of a counterflow virtual impactor at aerodynamic diameters from 1 to 15 μm. Aerosol Sci. Technol.,19, 317–329.

  • Busen, R., and A. L. Buck, 1993: A high performance hygrometer for air craft use: Description, installation, and flight data. Institute für Physik der Atmosphäre Rep. 10, 29 pp. [Available from Institute für Physik der Atmosphäre, Oberpffaffenhofen, D-82234 Weßling, Germany.].

  • Charlson, R. J., S. E. Schwartz, J. M. Hales, R. D. Cess, J. A. Coakley Jr., J. E. Hansen, and D. J. Hofmann, 1992: Climate forcing by anthropogenic aerosols. Science,255, 423–429.

  • DeMott, Paul J., M. P. Meyers, and W. R. Cotton, 1994: Parameterization and impact of ice initiation processes relevant to numerical model simulations of cirrus clouds. J. Atmos. Sci.,51, 77–90.

  • Dowling, D. R., and L. F. Radke, 1990: A summary of the physical properties of cirrus clouds. J. Appl. Meteor.,29, 970–978.

  • Hallett, J., 1976: Measurement of size, concentration and structure of atmospheric particulates by the airborne continuous particle replicator. Report AFGL-TR-76-0149, 92 pp. [Available from Desert Research Institute, University of Nevada System, Reno, NV 89507.].

  • Heymsfield, A. J., and R. M. Sabin, 1989: Cirrus crystal nucleation by homogeneous freezing of solution droplets. J. Atmos. Sci.,46, 2252–2264.

  • ——, and L. M. Miloshevich, 1993: Homogeneous ice nucleation and supercooled liquid water in orographic wave clouds. J. Atmos. Sci.,50, 2335–2353.

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

  • Jensen, E. J., O. B. Toon, D. L. Westphal, S. Kinne, and A. J. Heymsfield, 1994a: Microphysical modeling of cirrus 1: Comparison with 1986 FIRE IFO measurements. J. Geophys Res.,99D, 10421–10442.

  • ——, ——, ——, ——, and ——, 1994b: Microphysical modeling of cirrus 2: Sensitivity studies. J. Geophys. Res.,99D, 10443–10454.

  • Kinne, S., T. P. Ackerman, A. J. Heymsfield, F. P. J. Valero, K. Sassen, and J. D. Spinhirne, 1992: Cirrus microphysics and radiative transfer: Cloud field study on 28 October 1986. Mon. Wea. Rev.,120, 661–684.

  • Lin, H., and J. Heintzenberg, 1995: A theoretical study of the counterflow virtual impactor. J. Aerosol Sci.,26, 903–918.

  • ——, and K. J. Noone, 1996: A simulation of cloud formation and sampling using the counterflow virtual impactor. Contrib. Atmos. Phys.,69, 321–332.

  • Liou, K. N., 1986: Influence of cirrus clouds on weather and climate processes: A global perspective. Mon. Wea. Rev.,114, 1167–1199.

  • Noone, K. B., K. J. Noone, J. Heintzenberg, J. Ström, and J. A. Ogren, 1993: In situ observations of cirrus cloud microphysical properties using the counterflow virtual impactor. J. Atmos. Oceanic Technol.,10, 294–303.

  • Noone, K. J., J. A. Ogren, J. Heintzenberg, R. J. Charlson, and D. S. Covert, 1988: Design and calibration of a counterflow virtual impactor for sampling of atmospheric fog and cloud droplets. Aerosol Sci. Technol.,8, 235–244.

  • ——, ——, and ——, 1990: An examination of clouds at a mountain-top site in central Sweden: The distribution of solute within cloud droplets. Atmos. Res.25, 3–15.

  • Ogren, J. A., J. Heintzenberg, and R. J. Charlson, 1985: In situ sampling of clouds with a droplet to aerosol converter. Geophys. Res. Lett.,12, 121–124.

  • Sassen, K., and G. C. Dodd, 1989: Haze particles nucleation simulations in cirrus clouds, and applications for numerical modeling and lidar studies. J. Atmos. Sci.,46, 3005–3014.

  • Schröder, F., and J. Ström, 1995: Aircraft measurements of sub micrometer aerosol particles (>7 nm) in the midlatitude free troposphere and tropopause region. F.L. thesis, Department of Meteorology, Stockholm University, 22 pp.

  • Starr, D. O., and S. Cox, 1985: Cirrus clouds. Part I: A cirrus cloud model. J. Atmos. Sci.,42, 2663–2681.

  • Ström, J., and J. Heintzenberg, 1994: Water vapor, condensed water, and crystal concentration in orographically influenced cirrus clouds. J. Atmos. Sci.,51, 2368–2383.

  • ——, ——, K. J. Noone, K. B. Noone, J. A. Ogren, F. Albers, and M. Quante, 1994a: Small crystal in cirriform clouds: A case study of residue size distribution, cloud water content and related cloud properties. Atmos. Res.,32, 125–141.

  • ——, R. Busen, M. Quante, B. Guillemet, P. R. A. Brown, and J. Heintzenberg, 1994b: Pre-EUCREX intercomparison of airborne humidity measuring instruments. J. Atmos. Oceanic Technol.,11, 1392–1399.

  • ——, B. Strauss, F. Shröder, T. Anderson, J. Heintzenberg, and P. Wendling, 1997: In situ observations of the microphysical properties of young cirrus clouds, J. Atmos. Sci.,54, 2542–2553.

  • Zender, C. S., and J. T. Kiehl, 1994: Radiative sensitivities of tropical anvils to small ice crystals. J. Geophys. Res.,99, 25869–25880.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 55 55 3
PDF Downloads 34 34 1

Small Ice Crystals in Cirrus Clouds: A Model Study and Comparison with In Situ Observations

View More View Less
  • 1 Atmospheric Environment Service, Downsview, Ontario, Canada
  • | 2 Department of Meteorology, Stockholm University, Stockholm, Sweden
  • | 3 National Center for Atmospheric Research, Boulder, Colorado
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

An air parcel model including homogeneous freezing nucleation of ice crystals has been used to study the formation and development of cirrus clouds. In situ measurements taken during March 1994 over southern Germany were used for comparison with model predictions. Typical experimental data were chosen for a base-case model run. Using measured aerosol properties as input values, the model predicts the measured ice crystal size distribution. In particular, both measurements and model results show the presence of numerous small ice crystals (diameter between 1 and 20 μm). Both measurements and model results also show that small aerosol particles (below 0.1 μm diameter) are active in forming cirrus cloud particles. The modeled microphysical properties including ice crystal size distribution, number concentration, and the residual particle size distribution are in good agreement with the experimental data. Based on the measured parameter values, a model sensitivity study considering air parcel updraft velocity, initial temperature, relative humidity, aerosol size distribution, number concentration, and air parcel vertical displacement is presented.

Corresponding author address: Dr. Hong Lin, Cloud Physics Research Division, Atmospheric Environment Service, 4905 Dufferin Street, Downsview, ON M3H 5T4, Canada.

Email: lin@armph3.tor.ec.gc.ca

Abstract

An air parcel model including homogeneous freezing nucleation of ice crystals has been used to study the formation and development of cirrus clouds. In situ measurements taken during March 1994 over southern Germany were used for comparison with model predictions. Typical experimental data were chosen for a base-case model run. Using measured aerosol properties as input values, the model predicts the measured ice crystal size distribution. In particular, both measurements and model results show the presence of numerous small ice crystals (diameter between 1 and 20 μm). Both measurements and model results also show that small aerosol particles (below 0.1 μm diameter) are active in forming cirrus cloud particles. The modeled microphysical properties including ice crystal size distribution, number concentration, and the residual particle size distribution are in good agreement with the experimental data. Based on the measured parameter values, a model sensitivity study considering air parcel updraft velocity, initial temperature, relative humidity, aerosol size distribution, number concentration, and air parcel vertical displacement is presented.

Corresponding author address: Dr. Hong Lin, Cloud Physics Research Division, Atmospheric Environment Service, 4905 Dufferin Street, Downsview, ON M3H 5T4, Canada.

Email: lin@armph3.tor.ec.gc.ca

Save