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Rain Fallspeeds and Rates Derived from Airborne Nadir-Pointing Doppler Radar MeasurementsThe use of vertical-incidence Doppler velocity in addition to radar reflectivity may yield information on drop size distribution and therefore result in better rainrate estimates. Doppler velocity can provide useful information on the raindrop size distribution. Doppler velocities from a zenith-pointing radar represent the sum of the mean reflectivity-weighted hydrometeor fallspeed and the vertical air motion. Dual-parameter rain estimation methods using the Doppler velocity, require that the latter can be removed, or is negligible. Atlas et al. (1972) derived relations between Doppler velocity, reflectivity, and rain rate assuming an exponential size distribution for rain. Ulbrich (1994) expanded on this work by deriving the relation between the Doppler velocity and the reflectivity assuming a Gamma size distribution. This distribution provides a more realistic representation of the small rain drops. To get accurate information on raindrop size distributions with the above method, the air motions must be removed from the observed Doppler velocities
Document ID
19990109159
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Heymsfield, Gerald M. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Tian, L. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Geerts, Bart (NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1999
Subject Category
Meteorology And Climatology
Meeting Information
Meeting: Radar Meteorology
Location: Montreal
Country: Canada
Start Date: July 1, 1999
Sponsors: American Meteorology Society
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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