HR: 0800h
AN: H31B-0353    [Abstracts]
TI: An Explicit Microphysical Model for the Transient Evolution of the Vertical Structure of Warm Stratiform Rain: Application to Rainfall Radar Estimation
AU: * Prat, O P
EM: oprat@duke.edu
AF: Civil and Environmental Engineering Department, Pratt School of Engineering, Duke University, 121 Hudson Hall, Box 90287, Durham, NC 27708, United States
AU: Barros, A P
EM: barros@duke.edu
AF: Civil and Environmental Engineering Department, Pratt School of Engineering, Duke University, 121 Hudson Hall, Box 90287, Durham, NC 27708, United States
AU: Williams, C R
EM: Christopher.R.Williams@noaa.gov
AF: Physical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Mail Stop R/PSD5, 325 Broadway, Boulder, CO 80305, United States
AB: A rainshaft model of the stochastic advection equation with explicit representation of microphysics (coalescence, collisional breakup, condensation, and evaporation) is presented here as a dynamic simulator of raindrop size distributions in active storm systems (DSD) for use in physically-based retrieval of radar rainfall. The model was used to simulate the evolution of a stratiform rainfall observed event during TWP-ICE (Tropical Warm Pool – International Cloud Experiment). Transient DSD based on vertically Pointing Radars (VPR) retrieval, were imposed as realistic boundary conditions at the top of the column. The transient evolution of simulated vertical profiles of integral parameters such as drop number concentration, liquid water content (LWC), rainrate (RNT) and radar reflectivity factor (Z) were compared against Vertically Pointing Radars (VPR) estimates and ground based observations (Joss-Waldvogel Disdrometer). Results obtained suggest that the model is able to emulate with high accuracy the temporal and spatial evolution of the Reflectivity factor and with an acceptable level of confidence the evolution of the Rainrate and Liquid Water Content. More importantly the cross-comparison of modeling results with VPR and JWD observations showed that the model was able to significantly improve the description of the rain event for the lower level of the atmosphere where estimates provided VPR are not reliable. Recent progress including the extension of the one dimensional model to ice formation/melting mechanisms and aerosols processes will be also discussed.
DE: 1847 Modeling
DE: 1853 Precipitation-radar
DE: 1854 Precipitation (3354)
SC: Hydrology [H]
MN: 2007 Fall Meeting