Particle Impact and Breakup in Aircraft Measurement

German Vidaurre Desert Research Institute, Reno, Nevada

Search for other papers by German Vidaurre in
Current site
Google Scholar
PubMed
Close
and
John Hallett Desert Research Institute, Reno, Nevada

Search for other papers by John Hallett in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Measurements of cloud particle properties from aircraft by optical and impact techniques are subject to artifacts following particle breakup prior to detection. The impact kinetic energy to surface energy ratio (L) provides a breakup criterion at L ≥ 7 for water and ice with major fragmentation for L > 100. This applies to optical imaging probes for particle concentration, size, and projected area spectra measurement. Uncertainty arises should impacting particles shatter and disperse, defeating the intent of the original measurements. Particle shatter is demonstrated in Formvar replicas (University of North Dakota Citation) and video records of particle approach and impact on the Cloudscope (NCAR C-130, NASA DC-8) at airspeeds of 130 and 200 m s−1. Sufficient impact kinetic energy results in drop splash and ice shatter, with conversion to surface energy and ultimately thermal energy through viscous dissipation and ice defect production occurring down to the molecular scale. The problem is minimized in design by reducing the regions responsible for particle breakup to a minimum and locating sensors in regions inaccessible to shatter fragments.

Corresponding author address: John Hallett, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512. Email: hallett@dri.edu

Abstract

Measurements of cloud particle properties from aircraft by optical and impact techniques are subject to artifacts following particle breakup prior to detection. The impact kinetic energy to surface energy ratio (L) provides a breakup criterion at L ≥ 7 for water and ice with major fragmentation for L > 100. This applies to optical imaging probes for particle concentration, size, and projected area spectra measurement. Uncertainty arises should impacting particles shatter and disperse, defeating the intent of the original measurements. Particle shatter is demonstrated in Formvar replicas (University of North Dakota Citation) and video records of particle approach and impact on the Cloudscope (NCAR C-130, NASA DC-8) at airspeeds of 130 and 200 m s−1. Sufficient impact kinetic energy results in drop splash and ice shatter, with conversion to surface energy and ultimately thermal energy through viscous dissipation and ice defect production occurring down to the molecular scale. The problem is minimized in design by reducing the regions responsible for particle breakup to a minimum and locating sensors in regions inaccessible to shatter fragments.

Corresponding author address: John Hallett, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512. Email: hallett@dri.edu

Save
  • Arnott, W. P., Dong Y. , Hallett J. , and Poellot M. , 1994: Role of small ice crystals in radiative properties of cirrus: A case study, FIRE II, November 22, 1991. J. Geophys. Res., 99 , 13711381.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Emery, E. F., Miller D. R. , Plaskon S. R. , Strapp W. , and Lillie L. , 2004: Ice particle impact on cloud water content instrumentation. Proc. 42nd Aerospace Sciences Meeting and Exhibit, Reno, NV, AIAA, AIAA-2004-0731.

    • Search Google Scholar
    • Export Citation
  • Field, P. R., Wood R. , and Brown P. R. A. , 2003: Ice particle interarrival times measured with a fast FSSP. J. Atmos. Oceanic Technol., 20 , 249261.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gardiner, B. A., and Hallett J. , 1985: Degradaton of in-cloud forward scattering spectrometer probe measurements in the presence of ice particles. J. Atmos. Oceanic Technol., 2 , 171180.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Garner, B. W., 2001: On the density of atmospheric particles. M.S. thesis, Dept. of Atmospheric Sciences, University of Nevada, Reno, 174 pp.

  • Goodman, M., and Hardin D. , cited 2008: 3rd Convection and Moisture Experiment (CAMEX). NASA. [Available online at http://ghrc.nsstc.nasa.gov/camex3/.].

  • Hallett, J., 1976: Measurement of size, concentrations and structure of atmospheric particulates by the airborne continuous particle replicator. Air Force Geophysics Laboratory Rep. AFGL-TR-76-0149, Hanscom AFB, MA, 92 pp.

    • Search Google Scholar
    • Export Citation
  • Hallett, J., and Christensen L. , 1984: Splash and penetration of drops in water. J. Rech. Atmos., 18 , 226262.

  • Hallett, J., and Isaac G. , 2002: Aircraft icing in glaciated and mixed phase clouds. Proc. 40th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, AIAA, AIAA-2002-0677.

    • Search Google Scholar
    • Export Citation
  • Ivanova, D. C., Mitchell D. L. , Arnott W. P. , and Poellot M. , 2001: A GCM parameterization for bimodal size spectra and ice mass removal rates in mid-latitude cirrus clouds. Atmos. Res., 59 , 89113.

    • Search Google Scholar
    • Export Citation
  • Jayaratne, E. R., Saunders C. P. R. , and Hallett J. , 1983: Laboratory studies of the charging of soft-hail during ice crystal interactions. Quart. J. Roy. Meteor. Soc., 109 , 609630.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kingsmill, D., and Coauthors, 2004: TRMM common microphysics products: A tool for evaluating spaceborne precipitation retrieval algorithms. J. Appl. Meteor., 43 , 15981618.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Knollenberg, R. G., 1981: Techniques for probing cloud microstructure. Clouds: Their Optical Properties and Effects, P. V. Hobbs and A. Deepak, Eds., Academic Press, 15–89.

    • Search Google Scholar
    • Export Citation
  • Korolev, A., and Isaac G. A. , 2005: Shattering during sampling by OAPs and HVPS. Part I: Snow particles. J. Atmos. Oceanic Technol., 22 , 528542.

  • Korolev, A., Strapp J. W. , and Isaac G. A. , 1998: The Nevzorov airborne hot-wire LWC-TWC probe: Principle of operation and performance characteristics. J. Atmos. Oceanic Technol., 15 , 14951510.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Langmuir, I., 1944: Atmospheric phenomena. Mathematical Investigation of Water Droplet Trajectories, Vol. 10, The Collected Works of Irving Langmuir, C. G. Suits, Ed., Pergamon Press, 348–393.

    • Search Google Scholar
    • Export Citation
  • McDonald, J. E., 1958: The physics of cloud modification. Advances in Geophysics, Vol. 5, Academic Press, 223–303.

  • McFarquhar, G., Um J. , Freer M. , Baumgardner D. , and Kok G. L. , 2007: Importance of small ice crystals to cirrus properties: Observations from the Tropical Warm Pool International Cloud Experiment (TWP-ICE). Geophys. Res. Lett., 34 , L13803. doi:10.1029/2007GL029865.

    • Search Google Scholar
    • Export Citation
  • Meyers, M. B., and Hallett J. , 2001: Micrometer-sized hygroscopic particles in the atmosphere: Aircraft measurement in the Arctic. J. Geophys. Res., 106 , 3406734080.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Mitchell, D. L., Rasch P. , Ivanova D. , McFarquhar G. , and Nousiainen T. , 2006: The impact of controversial small ice crystals on GCM simulations. Preprints, 12th Conf. on Cloud Physics, Madison, WI, Amer. Meteor. Soc., J2.9. [Available online at http://ams.confex.com/ams/pdfpapers/113642.pdf.].

    • Search Google Scholar
    • Export Citation
  • Noone, K. J., Ogren J. A. , Heintzenberg J. , Charlson R. J. , and Covert D. S. , 1988: Design and calibration of a counterflow virtual impactor for sampling of atmospheric fog and cloud droplets. Aerosp. Sci. Technol., 8 , 235244.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Pruppacher, H. R., and Klett J. D. , 2000: Microphysics of Clouds and Precipitation. 2nd ed. Kluwer, 976 pp.

  • Ranz, W. E., and Wong J. B. , 1952: Impaction of dust and smoke particles on surface and body collectors. J. Ind. Eng. Chem., 44 , 13711381.

  • Riley, J. T., 1998: Mixed-phase icing conditions: A review. Airport and Aircraft Safety Research and Development Rep. DOT/FAA/AR-98/76, Federal Aviation Administration, Atlantic City, NJ, 45 pp.

    • Search Google Scholar
    • Export Citation
  • Sassen, K., and Coauthors, 1995: The 5–6 December 1991 FIRE IFO II jet stream cirrus case study: The influence of volcanic aerosols. J. Atmos. Sci., 52 , 97123.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schwarzenbock, A., and Heintzenberg J. , 2000: Cut size minimization and cloud element break-up in a ground-based CVI. J. Aerosol Sci., 31 , 477489.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Twohy, C. H., Schanot A. J. , and Cooper W. A. , 1997: Measurement of condensed water content in liquid and ice clouds using an airborne counterflow virtual impactor. J. Atmos. Oceanic Technol., 14 , 197202.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Twohy, C. H., Strapp J. W. , and Wendisch M. , 2003: Performance of a counterflow virtual impactor in the NASA Icing Research Tunnel. J. Atmos. Oceanic Technol., 20 , 781790.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Vidaurre, G., and Hallett J. , 2006: Energetics of mixed phase cloud particle interactions. Preprints, 12th Conf. on Cloud Physics, Madison, WI, Amer. Meteor. Soc., P2.54. [Available online at http://ams.confex.com/ams/pdfpapers/112624.pdf.].

    • Search Google Scholar
    • Export Citation
  • Weber, R. J., Clarke A. D. , Litchy M. , Li J. , Kok G. , Schillawski R. D. , and McMurry P. H. , 1998: Spurious aerosol measurements when sampling from aircraft in the vicinity of clouds. J. Geophys. Res., 103 , (D21). 2833728346.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 398 96 2
PDF Downloads 341 95 7