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FAAR abstract instructions and template Please read carefully - the text contains instructions for abstract preparation CLOUD PARTICLES DISTRIBUTION IN A THUNDERSCLOUD I.M. GUBENKO1, K.G. RUBINSTEIN1 and M.M. KURBATOVA1 1 Hydrometeorological Research Center of the Russian Federation, 11-13, B. Predtechensky lane, Moscow, Russia Keywords: THUNDERSTORMS, NUMERICAL SIMULATION, CLOUD PARTICLES, ATMOSHERIC ELECTRICITY. INTRODUCTION Well-known that there is a close relationship between electrical and microphysical processes between cloud particles: electric field formation and charge separation interconnect to dynamics of air flow, moisture distribution and phase composition of the cloud. It is especially important for the thunderclouds since lightning discharges are the greatest threat to human, technical devices and engineering structures. For this moment the atmospheric electric field is insufficiently studied due to the lack of in-situ measurements in cumulus clouds at the mature stage. However, there are possibilities to use output data of numerical weather prediction models for explicit algorithms of thunderstorm forecast and analysis of spatio-temporal microphysical and electrical characteristics. Such techniques are based on computation of the electric field. The aim of presented work is the explicit electrification and lightning forecast using Cumulonimbus (Cb) electrification model implemented within the WRF-ARW (Weather Research and Forecast) model. WRFARW model has an option of many cloud microphysics parametrizations. In current research Thompson, Purdue Lin and WDM6 schemes including vapor and 5 classes of hydrometeors (ice and snow crystals, graupels, rain and cloud droplets) are studied (Lim, 2010; Lin et al, 1983; Thompson et al, 2004). So the objectives of this study are: 1.Physical and mathematical description of the Cb electrification model. 2.Analysis of spatio-temporal microphysical and electrical characteristics of solid particles in a simulated thunderstorm cloud for observed supercell storm in Moscow region, 13-14 of July, 2016. 3.Sensitivity test results of thresholds of the electrical characteristics of solid particles in Cb for the lightning activity occurrence to the type of used WRF-ARW microphysics parameterization schemes. METHODS The possibility of using the electrification model for the thunderstorm forecast is studied in this research. Cb electrification model uses ouput obtained from hydrodynamic mesoscale model WRF-ARW: profiles of hydrometeors’ fractions (snow, ice particles and graupels), cloud water content, air temperature and vertical wind component in the layer of 1020-300 hPa. Cb electrification model is a set of equations describing the processes of charge generation and separation in convective clouds, constants and profiles of meteorological data. Charge generation process is described by equations taking into account the diameters of interacting hydrometeors (snow, ice particles, graupels, cloud droplets), their concentration, the fraction of particles between which there was a collision /merger, the resulting charge from a collision/merger, gravitational speed of particles’ sedimentation and air temperature (Gardiner et al, 1985; MacGorman et a., 2001; Mansel et al, 2005; Ziegler et al., 1991). The model includes the equations describing non-inductive, inductive mechanisms and its combination the integrated schemes of charge generation. Non-inductive mechanism of the charge generation implies the interaction of solid hydrometeors (ice crystals+graupels, particles of snow+graupels). Inductive charging equation implies the interaction of FAAR abstract instructions and template Please read carefully - the text contains instructions for abstract preparation graupels and cloud droplets (Zeigler et al, 1991). Pairwise interaction between other hydrometeors is neglected because of the small charge generated as a result of the collision/merger between particles (Latham and Mason, 1962; Gaskel, 1989; Mansel et al, 2005). Charge separation unit of the elecrization model includes equations of the total volume charge, potential and electric field intensity. CONCLUSIONS Maximum concentration and terminal speeds of solid hydrometeors and their total space densities strongly depend on used WRF-ARW microphysics parameterization scheme. So there are no any common thresholds for the lightning prediction. Model spatio-temporal microphysical and electrical characteristics do not contradict the results obtained experimentally in studies of electricity in thunderclouds and radar maps of observed convective cells (Mansell, 2005). ACKNOWLEDGEMENTS This work was supported by the Russian Foundation for Basic Research under grants А 14-08-01105, А 15-05-02395 and A 16-05-00822. REFERENCES Gardiner B., D. Lamb and R. Pitter (1986). Measurements of initial potential gradient and particle charges in a Montana summer thunderstorm, J. of Geophysical Research 90, N D4, 6079-6086. Gaskell W. (1981). A laboratory study of the inductive theory of thunderstorm electrification, Quarterly Journal of Royal Meteorological Society 107, N 454, 955-966. Latham J. and B.J. Mason (1962). Electrical charging of hail pellets in a polarizing electric field, Proc. R. Soc. London, Ser. A., 266, 387-401. Lim K.-S.S. (2010). 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A model evaluation of noninductive graupel-ice charging in the early electrization of a mountain thunderstorm, J. of Geophysical Research 96, N D7, 12833-12855.