The Role of Ice Growth/Evaporation Processes on the Ice Economy of Clouds

冰生长/蒸发过程对云冰经济的作用

• 批准号: 9900560
• 负责人: John Hallett
• 金额: $ 38.64万
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9900560&HistoricalAwards=false
• 关键词: Role; Ice; Growth; Evaporation; Processes

This project consists of a broad range of laboratory experiments on the growth and evaporation of ice crystals and the analysis of existing cloud data collected by aircraft. One set of experiments will simulate the conditions of crystal growth in cirrus clouds. Modifications to an existing cloud chamber will permit temperatures as cold as -100 C, pressures as low as 1 mb, and supersaturations with respect to ice as high as 200%. The chamber will be modified to permit the examination of impurities, in particular oxides of nitrogen, on crystal habit. Results for these experiments will contribute to the understanding of crystal growth at the extreme conditions in cirrus clouds in the high atmosphere. Another set of experiments at temperatures around 0 C will be designed to study aspects of particle growth, melting, and evaporation relevant to the melting layer of snow. Emphasis will be on conditions with high supersaturations with respect to water, to simulate ice as it falls and melts in air with and without cloud droplets. Electrical effects and secondary ice production will be monitored. Data from the CALJET and SHEBA projects using the airborne "cloudscope" instrument will be compared with laboratory results on both the cirrus cloud and the melting layer simulations.

该项目包括一系列关于冰晶生长和蒸发的实验室实验，以及对飞机收集的现有云数据的分析。其中一组实验将模拟卷云中晶体生长的条件。对现有云室的改造将允许温度低至-100摄氏度，压力低至1mb，以及对冰的过饱和度高达200%。试验室将进行改装，以允许对杂质，特别是氮氧化物，进行结晶习惯的检查。这些实验的结果将有助于理解高层大气中卷云中极端条件下的晶体生长。另一组温度在0摄氏度左右的实验将被设计用来研究与积雪融化层相关的颗粒生长、融化和蒸发的方面。重点将放在相对于水具有高过饱和度的条件下，模拟冰在有或没有云滴的情况下降落和融化在空气中的情况。将监测电气效应和二次结冰。CALJET和SHEBA项目使用机载“云镜”仪器的数据将与实验室对卷云和融化层模拟的结果进行比较。