A Moment-Based Polarimetric Radar Forward Operator for Rain Microphysics
- Department of Meteorology and Atmospheric Science, The Pennsylvania State University, University Park, Pennsylvania
- North Carolina Institute for Climate Studies, North Carolina State University, Asheville, North Carolina
- Argonne National Laboratory, Chicago, Illinois
- Center for Climate Systems Research, Columbia University, and NASA Goddard Institute for Space Studies, New York, New York
- National Center for Atmospheric Research, Boulder, Colorado
There is growing interest in combining microphysical models and polarimetric radar observations to improve our understanding of storms and precipitation. Mapping model-predicted variables into the radar observational space necessitates a forward operator, which requires assumptions that introduce uncertainties into model–observation comparisons. These include uncertainties arising from the microphysics scheme a priori assumptions of a fixed drop size distribution (DSD) functional form, whereas natural DSDs display far greater variability. To address this concern, this study presents a moment-based polarimetric radar forward operator with no fundamental restrictions on the DSD form by linking radar observables to integrated DSD moments. The forward operator is built upon a dataset of >200 million realistic DSDs from one-dimensional bin microphysical rain-shaft simulations, and surface disdrometer measurements from around the world. Furthermore, this allows for a robust statistical assessment of forward operator uncertainty and quantification of the relationship between polarimetric radar observables and DSD moments. Comparison of “truth” and forward-simulated vertical profiles of the polarimetric radar variables are shown for bin simulations using a variety of moment combinations. Higher-order moments (especially those optimized for use with the polarimetric radar variables: the sixth and ninth) perform better than the lower-order moments (zeroth and third) typically predicted by many bulk microphysics schemes.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States); Columbia Univ., New York, NY (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23). Atmospheric System Research; National Science Foundation (NSF); USDOE
- Grant/Contract Number:
- AC02-06CH11357; SC0016579
- OSTI ID:
- 1492119
- Alternate ID(s):
- OSTI ID: 1510038; OSTI ID: 1844478
- Journal Information:
- Journal of Applied Meteorology and Climatology, Journal Name: Journal of Applied Meteorology and Climatology Vol. 58 Journal Issue: 1; ISSN 1558-8424
- Publisher:
- American Meteorological SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
The Potential for Discriminating Microphysical Processes in Numerical Weather Forecasts Using Airborne Polarimetric Radio Occultations
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journal | September 2019 |
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