Editorial Type:
Article
Article Type:
Research Article

The Influence of Terrain on Rainfall Estimates from Radar Reflectivity and Specific Propagation Phase Observations

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

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David N. Yates National Center for Atmospheric Research, Boulder, Colorado

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

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Print Publication:
01 Jul 1999
DOI:
https://doi.org/10.1175/1520-0426(1999)016<0837:TIOTOR>2.0.CO;2
Page(s):
837–845
Restricted access

Abstract

The effect of beam blockage on rainfall estimates derived from radar reflectivity and specific propagation phase was evaluated from measurements of a convective rainfall event from the National Center for Atmospheric Research’s S-band polarized (S-Pol) radar. This storm produced a flash flood in a mountainous watershed to the southwest of Denver, Colorado, and widespread rainfall over the plains. A beam blockage map of the region, based on a digital elevation model and characteristics of the S-Pol radiation pattern, was computed. Rain-rate estimates over both low and high beam-blockage areas were compared. Results supported the hypothesis that specific propagation phase–based quantitative precipitation estimates tend to be less influenced by terrain than reflectivity-based precipitation estimates are.

Corresponding author address: Dr. J. Vivekanandan, NCAR, P.O. Box 3000, Boulder, CO 80307.

Abstract

The effect of beam blockage on rainfall estimates derived from radar reflectivity and specific propagation phase was evaluated from measurements of a convective rainfall event from the National Center for Atmospheric Research’s S-band polarized (S-Pol) radar. This storm produced a flash flood in a mountainous watershed to the southwest of Denver, Colorado, and widespread rainfall over the plains. A beam blockage map of the region, based on a digital elevation model and characteristics of the S-Pol radiation pattern, was computed. Rain-rate estimates over both low and high beam-blockage areas were compared. Results supported the hypothesis that specific propagation phase–based quantitative precipitation estimates tend to be less influenced by terrain than reflectivity-based precipitation estimates are.

Corresponding author address: Dr. J. Vivekanandan, NCAR, P.O. Box 3000, Boulder, CO 80307.

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