• Albrecht, B., , P. Kollias, , R. Lhermitte, , and R. Peters. 1999. Observations of tropical cloud systems with a MM-wavelength Doppler radar—An overview. Preprints, 29th Int. Conf. on Radar Meteorology, Montreal, QC, Canada, Amer. Meteor. Soc., CD-ROM, P3.18.

  • Battan, L. J. 1973. Radar Observation of the Atmosphere. University of Chicago Press, 324 pp.

  • Bohren, C. F., and D. R. Huffman. 1998. Absorption and Scattering of Light by Small Particles. Wiley & Sons, 544 pp.

  • Campbell, J. R., , D. L. Hlavka, , E. J. Welton, , C. J. Flynn, , D. D. Turner, , J. D. Spinhirne, , V. S. Scott, , and I. H. Hwang. 2002. Full-time, eye-safe cloud and aerosol lidar observation at Atmospheric Radiation Measurement Program sites: Instruments and data processing. J. Atmos. Oceanic Technol. 19:431442.

    • Search Google Scholar
    • Export Citation
  • Demoz, B., , D. Starr, , D. Whiteman, , K. Evans, , D. Hlavka, , and R. Peravali. 2000. Raman lidar detection of cloud base. Geophys. Res. Lett. 27:18991902.

    • Search Google Scholar
    • Export Citation
  • Dennis, A. S., and W. Hitchfield. 1990. Advances in precipitation physics following the advent of weather radar. Radar in Meteorology, D. Atlas, Ed., Amer. Meteor. Soc., 98–108.

    • Search Google Scholar
    • Export Citation
  • Di Girolamo, P., , B. B. Demoz, , and D. N. Whiteman. 2003. Model simulations of melting hydrometeors: A new bright band from melting frozen drops. Geophys. Res. Lett. 30.1626, doi:10.1029/2002GL016825.

    • Search Google Scholar
    • Export Citation
  • Ecklund, W. L., , C. R. Williams, , P. E. Johnston, , and K. S. Gage. 1999. A 3 GHz profiler for precipitating cloud studies. J. Atmos. Oceanic Technol. 16:309322.

    • Search Google Scholar
    • Export Citation
  • Fabry, F., and I. Zawadski. 1995. Long-term radar observations in the melting layer of precipitation and their interpretation. J. Atmos. Sci. 52:838851.

    • Search Google Scholar
    • Export Citation
  • Fabry, F., and W. Szyrmer. 1999. Modeling of the melting layer. Part II: Electromagnetic. J. Atmos. Sci. 56:35933600.

  • Joss, J., and A. Waldvogel. 1990. Precipitation measurement and hydrology. Radar in Meteorology, D. Atlas, Ed., Amer. Meteor. Soc., 577–597.

    • Search Google Scholar
    • Export Citation
  • Kerker, M. 1969. The Scattering of Light and Other Electromagnetic Radiation. Academic Press, 666 pp.

  • Lhermitte, R. 1988. Observation of rain at vertical incidence with a 94 GHz Doppler radar: An insight on Mie scattering. Geophys. Res. Lett. 15:11251128.

    • Search Google Scholar
    • Export Citation
  • Lhermitte, R. 2002. Centimeter and Millimeter Wavelength Radars in Meteorology. Lhermitte Productions, 550 pp.

  • Meneghini, R., and L. Liao. 2000. Effective dielectric constants of mixed-phase hydrometeors. J. Atmos. Oceanic Technol. 17:628640.

  • Michaels, P. J. 1985. Anomalous mid-atmospheric heights and persistent thunderstorm patterns over Florida. J. Climatol. 5:529542.

  • Mitra, S. K., , O. Vohl, , M. Ahr, , and H. R. Pruppacher. 1990. A wind tunnel and theoretical study of the melting behavior of atmospheric ice particles. VI: Experiment and theory for snow flakes. J. Atmos. Sci. 47:584591.

    • Search Google Scholar
    • Export Citation
  • Moran, K. P., , B. E. Martner, , M. J. Post, , R. A. Kropfli, , D. C. Welsh, , and K. B. Widener. 1998. An unattended cloud-profiling radar for use in climate research. Bull. Amer. Meteor. Soc. 79:443455.

    • Search Google Scholar
    • Export Citation
  • Oraltay, R. G., and J. Hallett. 1989. Evaporation and melting of ice crystals: A laboratory study. Atmos. Res. 24:169189.

  • Oraltay, R. G., and J. Hallett. 2005. The melting layer: A laboratory investigation of ice particle melt and evaporation near 0°C. J. Appl. Meteor. 44:206220.

    • Search Google Scholar
    • Export Citation
  • Pruppacher, H. R., and K. Beard. 1970. A wind tunnel investigation of the internal circulation and shape of water drops falling at terminal velocity in air. Quart. J. Roy. Meteor. Soc. 96:247256.

    • Search Google Scholar
    • Export Citation
  • Ro, P. S., , T. S. Fahlen, , and H. C. Bryant. 1968. Precision measurement of water droplet evaporation rates. Appl. Opt. 7:883890.

  • Roy, G., and L. R. Bissonnette. 2001. Strong dependence of rain-induced lidar depolarization on the illumination angle: Experimental evidence and geometrical-optics interpretation. Appl. Opt. 40:47704780.

    • Search Google Scholar
    • Export Citation
  • Sassen, K. 1977a. Lidar observations of high plains thunderstorm precipitation. J. Atmos. Sci. 34:14441457.

  • Sassen, K. 1977b. Optical backscattering from near-spherical water, ice and mixed phase drops. Appl. Opt. 16:13321341.

  • Sassen, K., and T. Chen. 1995. The lidar dark band: An oddity of the radar bright band analogy. Geophys. Res. Lett. 22:35053508.

  • Sassen, K., and L. Liao. 1996. Estimation of cloud content by W-band radar. J. Appl. Meteor. 35:932938.

  • Simpson, J., , C. Kummerow, , W. K. Tao, , and R. F. Adler. 1996. On the Tropical Rainfall Measuring Mission (TRMM). Meteor. Atmos. Phys. 60:1936.

    • Search Google Scholar
    • Export Citation
  • Spinhirne, J. D. 1993. Micro pulse lidar. IEEE Trans. Geosci. Remote Sens. 31:4855.

  • Stephens, G. L. Coauthors 2002. The CloudSat mission and the A-train: A new dimension of space-based observations of clouds and precipitation. Bull. Amer. Meteor. Soc. 83:17711790.

    • Search Google Scholar
    • Export Citation
  • Stewart, R. E., , J. D. Marwitz, , J. C. Pace, , and R. E. Carbone. 1984. Characteristics through the melting layer of stratiform clouds. J. Atmos. Sci. 41:32273237.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 38 38 11
PDF Downloads 30 30 5

Lidar and Triple-Wavelength Doppler Radar Measurements of the Melting Layer: A Revised Model for Dark- and Brightband Phenomena

View More View Less
  • a Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska
  • b Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida
  • c NOAA/Environmental Technology Laboratory, Boulder, Colorado
  • d Cooperative Institute for Research in Environmental Sciences, University of Colorado, and NOAA Aeronomy Laboratory, Boulder, Colorado
© Get Permissions
Restricted access

Abstract

During the recent Cirrus Regional Study of Tropical Anvils and Cirrus Layers (CRYSTAL) Florida Area Cirrus Experiment (FACE) field campaign in southern Florida, rain showers were probed by a 0.523-μm lidar and three (0.32-, 0.86-, and 10.6-cm wavelength) Doppler radars. The full repertoire of backscattering phenomena was observed in the melting region, that is, the various lidar and radar dark and bright bands. In contrast to the ubiquitous 10.6-cm (S band) radar bright band, only intermittent evidence is found at 0.86 cm (K band), and no clear examples of the radar bright band are seen at 0.32 cm (W band), because of the dominance of non-Rayleigh scattering effects. Analysis also reveals that the relatively inconspicuous W-band radar dark band is due to non-Rayleigh effects in large water-coated snowflakes that are high in the melting layer. The lidar dark band exclusively involves mixed-phase particles and is centered where the shrinking snowflakes collapse into raindrops—the point at which spherical particle backscattering mechanisms first come into prominence during snowflake melting. The traditional (S band) radar brightband peak occurs low in the melting region, just above the lidar dark-band minimum. This position is close to where the W-band reflectivities and Doppler velocities reach their plateaus but is well above the height at which the S-band Doppler velocities stop increasing. Thus, the classic radar bright band is dominated by Rayleigh dielectric scattering effects in the few largest melting snowflakes.

Corresponding author address: Kenneth Sassen, 903 Koyukuk Drive, Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775. Email: ksassen@gi.alaska.edu

Abstract

During the recent Cirrus Regional Study of Tropical Anvils and Cirrus Layers (CRYSTAL) Florida Area Cirrus Experiment (FACE) field campaign in southern Florida, rain showers were probed by a 0.523-μm lidar and three (0.32-, 0.86-, and 10.6-cm wavelength) Doppler radars. The full repertoire of backscattering phenomena was observed in the melting region, that is, the various lidar and radar dark and bright bands. In contrast to the ubiquitous 10.6-cm (S band) radar bright band, only intermittent evidence is found at 0.86 cm (K band), and no clear examples of the radar bright band are seen at 0.32 cm (W band), because of the dominance of non-Rayleigh scattering effects. Analysis also reveals that the relatively inconspicuous W-band radar dark band is due to non-Rayleigh effects in large water-coated snowflakes that are high in the melting layer. The lidar dark band exclusively involves mixed-phase particles and is centered where the shrinking snowflakes collapse into raindrops—the point at which spherical particle backscattering mechanisms first come into prominence during snowflake melting. The traditional (S band) radar brightband peak occurs low in the melting region, just above the lidar dark-band minimum. This position is close to where the W-band reflectivities and Doppler velocities reach their plateaus but is well above the height at which the S-band Doppler velocities stop increasing. Thus, the classic radar bright band is dominated by Rayleigh dielectric scattering effects in the few largest melting snowflakes.

Corresponding author address: Kenneth Sassen, 903 Koyukuk Drive, Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775. Email: ksassen@gi.alaska.edu

Save