An Intercomparison of Model Simulations and VPR Estimates of the Vertical Structure of Warm Stratiform Rainfall during TWP-ICE

Abstract A model of rain shaft microphysics that solves the stochastic advection–coalescence–breakup equation in an atmospheric column was used to simulate the evolution of a stratiform rainfall event during the Tropical Warm Pool-International Cloud Experiment (TWP-ICE) in Darwin, Australia. For the first time, a dynamic simulation of the evolution of the drop spectra within a one-dimensional rain shaft is performed using realistic boundary conditions retrieved from real rain events. Droplet size distribution (DSD) retrieved from vertically pointing radar (VPR) measurements are sequentially imposed at the top of the rain shaft as boundary conditions to emulate a realistic rain event. Time series of model profiles of integral parameters such as reflectivity, rain rate, and liquid water content were subsequently compared with estimates retrieved from vertically pointing radars and Joss–Waldvogel disdrometer (JWD) observations. Results obtained are within the VPR retrieval uncertainty estimates. Besides eva...

[1]  P. Joe,et al.  Comparison of Raindrop Size Distribution Measurements by a Joss-Waldvogel Disdrometer, a PMS 2DG Spectrometer, and a POSS Doppler Radar , 1994 .

[2]  R. C. Srivastava,et al.  Doppler radar characteristics of precipitation at vertical incidence , 1973 .

[3]  G. Feingold,et al.  The Evolution of Raindrop Spectra. Part III: Downdraft Generation in an Axisymmetrical Rainshaft Model , 1991 .

[4]  K. Gage,et al.  Recent Developments in Observation, Modeling, and Understanding Atmospheric Turbulence and Waves , 2003 .

[5]  Determining reflectivity measurement error from serial measurements using paired disdrometers and profilers , 2004 .

[6]  Exploring the use of a column model for the characterization of microphysical processes in warm rain: results from a homogeneous rainshaft model , 2007 .

[7]  R. Gunn,et al.  THE TERMINAL VELOCITY OF FALL FOR WATER DROPLETS IN STAGNANT AIR , 1949 .

[8]  R. Cifelli,et al.  Comparison of Precipitation Estimation Using Single- and Dual-Frequency Wind Profilers: Simulations and Experimental Results , 1999 .

[9]  C. Ulbrich.  Natural Variations in the Analytical Form of the Raindrop Size Distribution , 1983 .

[10]  Brian E. Sheppard,et al.  Effect of Irregularities in the Diameter Classification of Raindrops by the Joss-Waldvogel Disdrometer , 1990 .

[11]  Kenneth S. Gage,et al.  Vertical Structure of Precipitation and Related Microphysics Observed by NOAA Profilers and TRMM during NAME 2004 , 2007 .

[12]  P. T. Willis,et al.  Functional fits to some observed drop size distributions and parameterization of rain , 1984 .

[13]  R. Vincent,et al.  Raindrop Size Distribution Retrievals from a VHF Boundary Layer Profiler , 2004 .

[14]  Firat Yener Testik,et al.  Toward elucidating the microstructure of warm rainfall: A survey , 2007 .

[15]  V. Chandrasekar,et al.  Evaluation of a New Polarimetrically Based Z–R Relation , 2004 .

[16]  Henri Sauvageot,et al.  The Shape of Averaged Drop Size Distributions , 1995 .

[17]  Susumu Kato,et al.  A Direct Method for Deriving Drop-Size Distribution and Vertical Air Velocities from VHF Doppler Radar Spectra , 1986 .

[18]  Olivier P. Prat,et al.  Revisiting Low and List (1982): Evaluation of Raindrop Collision Parameterizations Using Laboratory Observations and Modeling , 2008 .

[19]  James Duncan McTaggart-Cowan,et al.  Collision and Breakup of Water Drops at Terminal , 1975 .

[20]  David B. Wolff,et al.  Rain gauge and disdrometer measurements during the Keys Area Microphysics Project (KAMP) , 2003 .

[21]  Anthony J. Illingworth,et al.  The Need to Represent Raindrop Size Spectra as Normalized Gamma Distributions for the Interpretation of Polarization Radar Observations , 2002 .

[22]  C. Williams,et al.  Estimation of Rainfall Drop Size Distributions from Dual-Frequency Wind Profiler Spectra Using Deconvolution and a Nonlinear Least Squares Fitting Technique , 2002 .

[23]  R. C. Srivastava,et al.  Evolution of Raindrop Size Distribution by Coalescence, Breakup, and Evaporation: Theory and Observations , 1995 .

[24]  J. Marshall,et al.  THE DISTRIBUTION OF RAINDROPS WITH SIZE , 1948 .

[25]  J. Klett,et al.  Microphysics of Clouds and Precipitation , 1978, Nature.

[26]  Greg M. McFarquhar,et al.  The Evolution of Three-Peak Raindrop Size Distributions in One-Dimensional Shaft Models. Part II: Multiple Pulse Rain , 1990 .

[27]  Greg Michael McFarquhar,et al.  A New Representation of Collision-Induced Breakup of Raindrops and Its Implications for the Shapes of Raindrop Size Distributions , 2004 .

[28]  R. Stewart,et al.  Temporal evolution of drop spectra to collisional equilibrium in steady and pulsating rain , 1987 .

[29]  Olivier P. Prat,et al.  A Robust Numerical Solution of the Stochastic Collection–Breakup Equation for Warm Rain , 2007 .

[30]  Earl E. Gossard,et al.  Measurement of Cloud Droplet Size Spectra by Doppler Radar , 1994 .

[31]  D. Ramkrishna,et al.  On the solution of population balance equations by discretization—II. A moving pivot technique , 1996 .

[32]  Zev Levin,et al.  The Evolution of Raindrop Spectra. Part II: Collisional Collection/Breakup and Evaporation in a Rainshaft , 1989 .

[33]  C. Williams.  Simultaneous ambient air motion and raindrop size distributions retrieved from UHF vertical incident profiler observations , 2001 .

[34]  Greg Michael McFarquhar,et al.  The Effect of Curve Fits for the Disdrometer Calibration on Raindrop Spectra, Rainfall Rate, and Radar Reflectivity , 1993 .

[35]  Roland List,et al.  Collision, Coalescence and Breakup of Raindrops. Part I: Experimentally Established Coalescence Efficiencies and Fragment Size Distributions in Breakup , 1982 .

[36]  Roland List,et al.  Collision, Coalescence and Breakup of Raindrops. Part II: Parameterization of Fragment Size Distributions , 1982 .

[37]  The effect of raindrop clustering on collision‐induced break‐up of raindrops , 2004 .