Laboratory, Field and Modeling Studies of Raindrop Shape

本研究的目的是调查 通过实验室、野外和建模， 问题研究 在实验室里，一个28米长的竖井将被用来 评估空气动力反馈在持续的 振荡1.5至4.0 mm直径的液滴。 额外 实验计划使用100米的落差进行更大的跌落 柱 此外，现场测量的液滴振荡光谱和 将进行各种雨的振幅， 涡流脱落、液滴碰撞和湍流在 促进雨滴振荡。 该项目包括分析 由光学阵列测量的雨滴形状的飞机数据 对流和降水/带电期间的探测器 在佛罗里达进行的实验（1991年夏）。 自然的原因 雨滴形状将使用降雨率的测量来评估， 液滴尺寸分布、多普勒雷达反射率和 极化 最后，模型将使用这些 观察以表征雨中水滴形状的变化。 自然雨滴形状的半经验分布将是 应用于微波散射和极化问题。

The objective of this research is the investigate of the natural shapes of raindrops through laboratory, field and modeling studies. In the laboratory, a 28-meter shaft will be used to evaluate the role of aerodynamic feedback in the persistent oscillation for 1.5 to 4.0 mm diameter drops. Additional experiments are planned for larger drops using a 100-meter fall column. Also, field measurements of drop oscillation spectra and amplitudes in various types of rain will be conducted to examine the roles of eddy shedding, drop collisions and turbulence in promoting raindrop oscillations. The project includes the analysis of aircraft data of raindrop shape as measured by an optical-array probe during the Convective and Precipitation/Electrification Experiment in Florida (Summer 1991). The causes of natural raindrop shapes will be evaluated using measurements of rain rates, drop-size distributions, Doppler radar reflectivities and polarization. Finally, models will be developed using these observations to characterize the variety of drop shapes in rain. The semi-empirical distributions of natural raindrop shapes will be applied to problems in microwave scattering and polarization.