Editorial Type:
Article
Article Type:
Research Article

An Evaluation of a Drop Distribution–Based Polarimetric Radar Rainfall Estimator

Edward A. Brandes National Center for Atmospheric Research,* Boulder, Colorado

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Guifu Zhang National Center for Atmospheric Research,* Boulder, Colorado

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J. Vivekanandan National Center for Atmospheric Research,* Boulder, Colorado

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Print Publication:
01 May 2003
DOI:
https://doi.org/10.1175/1520-0450(2003)042<0652:AEOADD>2.0.CO;2
Page(s):
652–660
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Abstract

A method for estimating the governing parameters of gamma drop size distributions (DSDs) and associated rainfall rates from polarimetric radar measurements at the S band is examined. The technique uses radar reflectivity at horizontal polarization, differential reflectivity, and an empirical constraining relationship between the DSD shape factor and slope parameter. Retrieved DSD parameters show good agreement with disdrometer observations. Retrieved rainfall estimates are insensitive to drop climatological regime. Comparison with fixed-form power-law estimators reveals that the constrained-gamma method outperforms reflectivity estimators and is roughly equivalent to radar reflectivity–differential reflectivity estimators optimized for local DSDs.

Corresponding author address: Dr. Edward A. Brandes, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307. brandes@ncar.ucar.edu

Abstract

A method for estimating the governing parameters of gamma drop size distributions (DSDs) and associated rainfall rates from polarimetric radar measurements at the S band is examined. The technique uses radar reflectivity at horizontal polarization, differential reflectivity, and an empirical constraining relationship between the DSD shape factor and slope parameter. Retrieved DSD parameters show good agreement with disdrometer observations. Retrieved rainfall estimates are insensitive to drop climatological regime. Comparison with fixed-form power-law estimators reveals that the constrained-gamma method outperforms reflectivity estimators and is roughly equivalent to radar reflectivity–differential reflectivity estimators optimized for local DSDs.

Corresponding author address: Dr. Edward A. Brandes, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307. brandes@ncar.ucar.edu

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Journal of Applied Meteorology and Climatology

  • Aydin, K. and V. Giridhar. 1992. C-band dual-polarization radar observables in rain. J. Atmos. Oceanic Technol. 9:383–390.

  • Brandes, E. A., G. Zhang, and J. Vivekanandan. 2002. Experiments in rainfall estimation with a polarimetric radar in a subtropical environment. J. Appl. Meteor. 41:674–685.

    • Search Google Scholar
    • Export Citation

  • Chandrasekar, V. and V. N. Bringi. 1987. Simulation of radar reflectivity and surface measurements of rainfall. J. Atmos. Oceanic Technol. 4:464–478.

    • Search Google Scholar
    • Export Citation

  • Direskeneli, H., K. Aydin, and T. A. Seliga. 1986. Radar estimation of rainfall rate using reflectivity and differential reflectivity measurements obtained during Maypole '84: Comparison with ground-based rain gauges. Preprints, 23d Conf. on Radar Meteorology, Snowmass, CO, Amer. Meteor. Soc., 116–120.

    • Search Google Scholar
    • Export Citation

  • Goddard, J. W. F. and S. M. Cherry. 1984. The ability of dual polarization radar (co-polar linear) to predict rainfall rate and microwave attenuation. Radio Sci. 19:201–208.

    • Search Google Scholar
    • Export Citation

  • Goddard, J. W. F., J. Tan, and M. Thurai. 1994. Technique for calibration of meteorological radars using differential phase. Electron. Lett. 30:166–167.

    • Search Google Scholar
    • Export Citation

  • Gorgucci, E., V. Chandrasekar, and G. Scarchilli. 1995. Radar and surface measurement of rainfall during CaPE: 26 July 1991 case study. J. Appl. Meteor. 34:1570–1577.

    • Search Google Scholar
    • Export Citation

  • Gorgucci, E., G. Scarchilli, and V. Chandrasekar. 1999. A procedure to calibrate multiparameter weather radar using properties of the rain medium. IEEE Trans. Geosci. Remote Sens. 37:269–276.

    • Search Google Scholar
    • Export Citation

  • Gunn, R. and G. D. Kinzer. 1949. The terminal velocity of fall for water droplets in stagnant air. J. Meteor. 6:243–248.

  • Ishimaru, A. 1991. Electromagnetic Wave Propagation, Radiation, and Scattering. Prentice Hall, 637 pp.

  • Joss, J. and A. Waldvogel. 1967. Ein spectrograph für Niederschagstropfen mit automatisher Auswertung (A spectrograph for the automatic analysis of raindrops). Pure Appl. Geophys. 68:240–246.

    • Search Google Scholar
    • Export Citation

  • Kruger, A. and W. F. Krajewski. 2002. Two-dimensional video disdrometer: A description. J. Atmos. Oceanic Technol. 19:602–617.

  • Nešpor, V., W. F. Krajewski, and A. Kruger. 2000. Wind-induced error of raindrop size distribution measurement using a two-dimensional video disdrometer. J. Atmos. Oceanic Technol. 17:1483–1492.

    • Search Google Scholar
    • Export Citation

  • Pruppacher, H. R. and R. L. Pitter. 1971. A semi-empirical determination of the shape of cloud and rain drops. J. Atmos. Sci. 28:86–94.

    • Search Google Scholar
    • Export Citation

  • Ryzhkov, A. V. and D. S. Zrnić. 1994. Precipitation observed in Oklahoma mesoscale convective systems with a polarimetric radar. J. Appl. Meteor. 33:455–464.

    • Search Google Scholar
    • Export Citation

  • Ryzhkov, A. V. and D. S. Zrnić. 1995. Comparison of dual-polarization radar estimators of rain. J. Atmos. Oceanic. Technol. 12:249–256.

    • Search Google Scholar
    • Export Citation

  • Sachidananda, M. and D. S. Zrnić. 1987. Rain rate estimates from differential polarization measurements. J. Atmos. Oceanic Technol. 4:588–598.

    • Search Google Scholar
    • Export Citation

  • Sauvageot, H. and J. Lacaux. 1995. The shape of averaged drop size distributions. J. Atmos. Sci. 52:1070–1083.

  • Scarchilli, G., E. Gorgucci, V. Chandrasekar, and A. Dobaie. 1996. Self-consistency of polarization diversity measurement of rainfall. IEEE Trans. Geosci. Remote Sens. 34:22–26.

    • Search Google Scholar
    • Export Citation

  • Seliga, T. A. and V. N. Bringi. 1976. Potential use of radar differential reflectivity measurements at orthogonal polarizations for measuring precipitation. J. Appl. Meteor. 15:69–76.

    • Search Google Scholar
    • Export Citation

  • Seliga, T. A. and V. N. Bringi. 1978. Differential reflectivity and differential phase shift: Applications in radar meteorology. Radio Sci. 13:271–275.

    • Search Google Scholar
    • Export Citation

  • Seliga, T. A., V. N. Bringi, and H. H. Al-Khatib. 1981. A preliminary study of comparative measurements of rainfall rate using the differential reflectivity radar technique and a raingage network. J. Appl. Meteor. 20:1362–1368.

    • Search Google Scholar
    • Export Citation

  • Tokay, A., A. Kruger, and W. Krajewski. 2001. Comparison of drop size distribution measurements by impact and optical disdrometers. J. Appl. Meteor. 40:2083–2097.

    • Search Google Scholar
    • Export Citation

  • Ulbrich, C. W. 1983. Natural variations in the analytical form of the raindrop size distribution. J. Climate Appl. Meteor. 22:1764–1775.

    • Search Google Scholar
    • Export Citation

  • Ulbrich, C. W. and D. Atlas. 1998. Rainfall microphysics and radar properties: Analysis methods for drop size spectra. J. Appl. Meteor. 37:912–923.

    • Search Google Scholar
    • Export Citation

  • Vivekanandan, J., G. Zhang, S. M. Ellis, D. Rajopadhyaya, and S. K. Avery. 2003. Radar reflectivity calibration using differential propagation phase measurement. Radio Sci., in press.

    • Search Google Scholar
    • Export Citation

  • Zhang, G., J. Vivekanandan, and E. Brandes. 2001. A method for estimating rain rate and drop size distribution from polarimetric radar measurements. IEEE Trans. Geosci. Remote Sens. 39:830–841.

    • Search Google Scholar
    • Export Citation

  • Zhang, G., J. Vivekanandan, E. Brandes, R. Meneghini, and T. Kozu. 2003. The shape–slope relation in observed gamma raindrop size distributions: Statistical error or useful information? J. Atmos. Oceanic Technol., in press.

    • Search Google Scholar
    • Export Citation
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