Advanced Comprehensive Analysis of Rain Drop Shapes, Oscillation Modes, and Fall Velocities Using High-Resolution Surface Disdrometers, Polarimetric Radar, and Numerical Models

使用高分辨率表面测距仪、偏振雷达和数值模型对雨滴形状、振荡模式和降落速度进行高级综合分析

• 批准号: 1431127
• 负责人: Viswanathan Bringi
• 金额: $ 49.92万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1431127&HistoricalAwards=false
• 关键词: Advanced; Comprehensive; Analysis; Rain; Drop

Raindrops do not stay in a constant state as they fall towards the surface. They can change shape, size, and speed. Weather radars can measure some of these aspects, but need to rely on assumptions about others. This project will combine observations of droplets with numerical modeling to provide researchers a better idea about how many of each size of drops there are, how the drops interact when they collide, and how the radar views the droplets. The result will be better data for the estimation of precipitation from radars, which impacts flood forecasting and hydrology. The project will also provide training opportunities for students, the next generation of scientists. The research team will combine observational analysis with numerical models in order to increase the accuracy and completeness of rain drop sizes, oscillations, and fall speeds. Knowledge of these quantities will enable a new evaluation of the importance of collisional-forcing of drop oscillation in moderate-to-intense rain rates. The observations and modeling will also allow the PIs to create new "drop-by-drop" calculations of scattering matrices and polarimetric radar observables. The observational part of the project will take place at a highly instrumented site near the University of Alabama-Hunstville campus. The main instruments to be used will be the Meteorological Particle Spectrometer, for imaging and measurement of small drops, and the low-profile 2D-video disdrometer (2DVD) for overlap and larger drops. Modeling work will consist of extending the "drop-by-drop" scattering methodology to include both symmetric and asymmetric shapes, the latter computations to be based on advance method-of-moments surface-integral-equation techniques.

当雨滴朝向表面时，它们不会保持恒定状态。 它们可以改变形状，尺寸和速度。 天气雷达可以衡量其中的某些方面，但需要依靠对其他方面的假设。 该项目将将液滴的观察结果与数值建模相结合，以使研究人员更好地了解其中有多少滴液滴，滴在碰撞时如何相互作用以及雷达如何看待液滴。 结果将是估计雷达降水的更好数据，这会影响洪水的预测和水文学。 该项目还将为下一代科学家提供培训机会。研究团队将将观察性分析与数值模型相结合，以提高降雨量，振荡和跌落速度的准确性和完整性。 对这些数量的了解将使对中度到强度降雨率在碰撞振荡的重要性进行新的评估。 观察结果和建模还将允许PI创建新的“逐滴”计算，来计算散射矩阵和偏光雷达可观测值。 该项目的观察部分将在阿拉巴马大学 - 亨斯特维尔大学校园附近的一个高度乐器地点举行。 要使用的主要仪器将是气象颗粒光谱仪，用于小滴的成像和测量，以及用于重叠和较大滴的低调的2D-VIDEO序列（2DVD）。 建模工作将包括扩展“逐滴”散射方法以包括对称形状和不对称形状，后者的计算是基于预先的弹奏方法表面整体方程技术的。