Beamwidth Effects on the Differential Phase Measurements of Rain

Alexander Ryzhkov Cooperative Institute for Mesoscale Meteorological Studies (CIMMS), University of Oklahoma, Norman, Oklahoma

Search for other papers by Alexander Ryzhkov in
Current site
Google Scholar
PubMed
Close
and
Dusan Zrnic National Severe Storms Laboratory, Norman, Oklahoma

Search for other papers by Dusan Zrnic in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Effects of beamfilling nonuniformities on the differential phase and rainfall estimation that use specific differential phase are examined. Two physical models are considered: an isolated rain cell with azimuthal dimensions comparable to the beamwidth and a sharp rain boundary approximating a squall line. The model results are compared to observations. An extension of the analysis to include observations of the melting layer is made. From this analysis emerges an interpretation of the radial profile of differential phase that varies from previous explanations. The current interpretation might be favored due to its simplicity and reliance on accepted physical properties of the melting layer.

Corresponding author address: Dr. Alexander V. Ryzhkov, NSSL/CIMMS, 1313 Halley Circle, Norman, OK 73069.

Email: ryzhkov@nsslsun.nssl.uoknor.edu

Abstract

Effects of beamfilling nonuniformities on the differential phase and rainfall estimation that use specific differential phase are examined. Two physical models are considered: an isolated rain cell with azimuthal dimensions comparable to the beamwidth and a sharp rain boundary approximating a squall line. The model results are compared to observations. An extension of the analysis to include observations of the melting layer is made. From this analysis emerges an interpretation of the radial profile of differential phase that varies from previous explanations. The current interpretation might be favored due to its simplicity and reliance on accepted physical properties of the melting layer.

Corresponding author address: Dr. Alexander V. Ryzhkov, NSSL/CIMMS, 1313 Halley Circle, Norman, OK 73069.

Email: ryzhkov@nsslsun.nssl.uoknor.edu

Save
  • Battan, L. J., 1973: Radar Observations of the Atmosphere. University of Chicago Press, 323 pp.

  • Caylor, J., and V. Chandrasekar, 1996: Time-varying ice crystal orientation in thunderstorms observed with multiparameter radar. IEEE Trans. Geosci. Remote Sens.,34, 847–858.

    • Crossref
    • Export Citation
  • Doviak, R. J., and D. S. Zrnic, 1993: Doppler Radar and Weather Observations. Academic Press, 562 pp.

  • Fabry, F., and I. Zawadzki, 1995: Long-term radar observations of the melting layer of precipitation and their interpretation. J. Atmos. Sci.,52, 838–851.

    • Crossref
    • Export Citation
  • Jefferys, W. H., and J. O. Berger, 1992: Ockham’s razor and Bayesian analysis. Amer. Sci.,80, 64–72.

  • Moninger, W. R., V. N. Bringi, T. R. Detman, J. R. Jordan, T. A. Seliga, and K. Aydin, 1984: Melting layer observations during MAYPOLE. Preprints, 22d Conf. on Radar Meteorology, Zurich, Switzerland, Amer. Meteor. Soc., 364–369.

  • Russchenberg, H. W. J., and L. P. Lighthart, 1996: Backscattering by and propagation through the melting layer of precipitation: A new polarimetric model. IEEE Trans. Geosci. Remote Sens.,34, 3–14.

    • Crossref
    • Export Citation
  • Ryzhkov, A. V., and D. S. Zrnic, 1996: Assessment of rainfall measurement that uses specific differential phase. J. Appl. Meteor.,35, 2080–2090.

    • Crossref
    • Export Citation
  • ——, and ——, 1998: Discrimination between rain and snow with a polarimetric radar. J. Appl. Meteor., in press.

  • ——, ——, and D. Atlas, 1997: Polarimetrically tuned R(Z) relations and comparison of radar rainfall methods. J. Appl. Meteor.,36, 340–349.

    • Crossref
    • Export Citation
  • Sachidananda, M., and D. S. Zrnic, 1987: Rain-rate estimates from differential polarization measurements. J. Atmos. Oceanic Technol.,4, 587–598.

    • Crossref
    • Export Citation
  • Zrnic, D. S., and A. V. Ryzhkov, 1996: Advantages of rain measurements using specific differential phase. J. Atmos. Oceanic Technol.,13, 454–464.

    • Crossref
    • Export Citation
  • ——, V. N. Bringi, N. Balakrishnan, K. Aydin, V. Chandrasekar, and J. Hubbert, 1993a: Polarimetric measurements in a severe hailstorm. Mon. Wea. Rev.,121, 2223–2238.

    • Crossref
    • Export Citation
  • ——, N. Balakrishnan, C. L. Ziegler, V. N. Bringi, K. Aydin, and T. Matejka, 1993b: Polarimetric signatures in the stratiform region of a mesoscale convective system. J. Appl. Meteor.,32, 678–693.

    • Crossref
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 241 46 8
PDF Downloads 118 24 2