CAREER: Laboratory Studies of Small-Scale Processes in Clouds

职业：云中小规模过程的实验室研究

• 批准号: 9984294
• 负责人: Raymond Shaw
• 金额: $ 44.99万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9984294&HistoricalAwards=false
• 关键词: CAREER; Laboratory; Studies; Small; Scale

The research component of this CAREER grant consists of laboratory investigations of two kinds of small-scale processes that are important for the formation and growth of water droplets in natural clouds: (1) kinetic effects, as characterized by the accommodation coefficient and the condensation coefficient, that determine the rates of exchange of heat and mass between a drop and its environment; (2) effects of small-scale turbulence on the interactions between drops and the humidity of their environment. The study of kinetic effects are conducted using an electrodynamic levitation cell coupled with an environmental control chamber that enables the observation of individual cloud particles. The effects of turbulence are carried out using an expansion chamber that includes provision for creating turbulence of variable intensity using internally mounted fans. Objectives of the research include (1) independent measurement of the accommodation coefficient and the condensation coefficient of pure water drops and solution drops over a range of temperature and pressure corresponding to conditions in the atmosphere; (2) studies of turbulence-induced humidity fluctuations on the growth rates of drops, using observed efflorescence of solution droplets as indicators of humidity fluctuations below a predetermined threshold. Results of the experiments will be a better understanding of the small scale processes in clouds that are precursors to the formation of precipitation. The educational component of the grant emphasizes undergraduate research. It consists of (1) working with teams of undergraduate students in the design, construction, and deployment of simple instruments for atmospheric measurements as part of the Midwest Rockets for Schools Program of Michigan Technical University and (2) mentoring upper-level undergraduates in laboratory research projects in cloud physics as part of the physics department's senior thesis program.

这项CAREER资助的研究部分包括对两种小尺度过程的实验室研究，这两种过程对自然云中水滴的形成和生长非常重要：（1）动力学效应，以调节系数和凝结系数为特征，决定水滴与其环境之间的热量和质量交换率;（2）小尺度湍流对液滴与环境湿度相互作用的影响。 动力学效应的研究是使用一个电动悬浮细胞与环境控制室，使个别云粒子的观察。 湍流的影响是使用膨胀室来实现的，该膨胀室包括使用内部安装的风扇来产生可变强度的湍流的装置。 研究的目标包括：（1）在与大气条件相对应的温度和压力范围内，独立测量纯水滴和溶液滴的容纳系数和冷凝系数;（2）使用观察到的溶液滴的风化作为低于预定阈值的湿度波动的指标，研究由温度和压力引起的湿度波动对液滴生长速率的影响。 实验结果将有助于更好地理解云的小尺度过程，这是降水形成的前兆。 补助金的教育部分强调本科生的研究。 它包括：（1）与本科生团队合作，设计，建造和部署用于大气测量的简单仪器，作为密歇根理工大学中西部火箭学校计划的一部分;（2）指导高水平的本科生在云物理实验室研究项目中，作为物理系高级论文计划的一部分。