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and fall velocity as a function of time under different temperatures and removed some obstacles caused by the lack of proper experimental data that have hindl~red cloud microphysical research. The analysis in this thesis was set out to fulftll at least the following four goals using the data sets from the previous experiments. First, some specific features: of microphysical theories have been verified with the experimental data. Second, time-dependent ecluations of ma~s, dimensions, and fall velocity applicable to different regimes of growth have been developed by considering the measured data and the functional styles of theories and not by merely obtaining a set of best fitting polynomials. Third, an empirical equation was derived by similar means to express the aerodynamic behavior of the falling ice crystal with the relationship among the Reynolds number, the Best number, and the axial ratio. Finally, a set of simplified parameterized equations has been gl~nerated that is experimentally consistent and suitable for cloud modeling and analysis. The empirical equations generated in this thesis based on the specific functional style of the theory have the advantage over the best fit polynomial equations, which have little support from physics and chemistry of the ice crystal growth and are valid only within the range of experimental data. Redder, C., and N. Fukuta, 1988: Empirical equations of ice crystal growth microphysics for modeling and analysis. Preprints, 10th International Cloud Physics Conference, IAMAP/lUGG, Bad Homburg, F.R.G., August 15-20, 1988. Annalen der Meteorologie, No. 25, IBSN 3-88148-240-7, 1:12-14. No abstract. Reinking, R. F., R. J. Meitin, F. Kopp, H. D. Orville, and J. L. Stith, 1992: Fields of motion and transport within a sheared thunderstonn. Atmospheric Research, 28:197-226. The fields of motion within a small, strongly sheared High Plains thunderstonn are examined using measurements of reflectivity and velocity from an airborne Doppler radar and other in situ measurements. The measurements are complemented by a high resolution two-dimensional numerical simulation of the storm. Implications fo, predicting stonn characteristics, delivery and effectiveness of seeding material, and precipitation efficiency are examined. The numerical model run was made in the forecasting mode 5 h before initial stonn development and 7 h before the observations of the mature stage. The main features of the simulated stonn struclture and motions are very similar to those measured, except that the model produced a vertically and temporally compressed stonn. The characteristics of the measured and the modeled stonn, in combination, are consistent with other theories and observations that precipitation efficiency is low and a large portion of the processed water substance is transported out through the anvil in thunderstonns that develop in an environment with strong wind speed shears in the vertical. The measurements and the model reveal a quasi-steady-state organization during the mature stage. Although the stonn fonned in response to surface heating, the simulation and the radar measurements in combination indicate that the relative importance of inflow' directly from the surface was diminished during the mature stage and completely cut off during the dissipation stage. Despite the modest size and intensity of this stonn, th'e actual circulation within it was highly three dimensional, and this, of course, could not be directly simulated by the two-dimensional model. Mature-stage inflows between about 3 and 6 kIn above ground level from a south-flank feeder cell field contributed significantly to the main updraft. Effective delivery of cloud seeding material to a stonn like this would be influenced by the three-dimensionallity and the relative importance of surface feeding in relation to inflows from levels above the surface. Such features would have to be deliennined in real time, and state-of-the-art technologies offer the means to do this. 61