Rain Drop Size Distributions Estimated from NOAA Snow-Level Radar Data
- Univ. of Colorado, Boulder, CO (United States); NOAA/Physical Sciences Lab., Boulder, CO (United States)
- Univ. of Colorado, Boulder, CO (United States)
- NOAA/Physical Sciences Lab., Boulder, CO (United States)
Using NOAA’s S-band High-Power Snow-Level Radar (HPSLR), a technique for estimating the rain drop size distribution (DSD) above the radar is presented. This technique assumes the DSD can be described by a four parameter, generalized gamma distribution (GGD). Using the radar’s measured average Doppler velocity spectrum and a value (assumed, measured, or estimated) of the vertical air motion w, an estimate of the GGD is obtained. Four different methods can be used to obtain w. One method that estimates a mean mass-weighted raindrop diameter Dm from the measured reflectivity Z produces realistic DSDs compared to prior literature examples. These estimated DSDs provide evidence that the radar can retrieve the smaller drop sizes constituting the “drizzle” mode part of the DSD. Here, this estimation technique was applied to 19 h of observations from Hankins, North Carolina. Results support the concept that DSDs can be modeled using GGDs with a limited range of parameters. Further work is needed to validate the described technique for estimating DSDs in more varied precipitation types and to verify the vertical air motion estimates.
- Research Organization:
- Univ. of Colorado, Boulder, CO (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER). Earth and Environmental Systems Science Division
- Grant/Contract Number:
- SC0021345
- OSTI ID:
- 1963104
- Journal Information:
- Journal of Atmospheric and Oceanic Technology, Vol. 39, Issue 3; ISSN 0739-0572
- Publisher:
- American Meteorological SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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