Droplet Nuclei and Condensed Water Content in Mixed-Phase Clouds

混合相云中的液滴核和凝结水含量

• 批准号: 0312036
• 负责人: Cynthia Twohy
• 金额: $ 27.97万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0312036&HistoricalAwards=false
• 关键词: Droplet; Nuclei; Condensed; Water; Content

This grant supports the participation of Dr. Twohy in the AIRS II project (second Alliance Icing Research Study), a collaboration of American, Canadian, and European agencies and institutions motivated by the important practical problem of aircraft icing. The AIRS field program is scheduled for the winter of 2003-2004 and based at Mirabel Airport, north of Montreal, Canada, where a surface observing network and ground-based remote-sensing equipment will be located. Dr. Twohy and her colleagues will be responsible for cloud microphysical observations aboard the NSF C-130 aircraft operating out of Cleveland, Ohio. The main scientific objective is to explain the circumstances by which regions of supercooled drops can form and continue to exist in clouds that may also contain ice crystals. The C-130 will be equipped for measuring the water content and ice content of clouds; the concentration, size, habit, and density of ice crystals; the concentration of ice-forming nuclei; the activity spectrum of cloud condensation nuclei (CCN); and the concentration and characteristics of aerosol particles both within the project area and in the air upstream of where the clouds of interest form. Dr. Twohy will be in charge of two instruments, a counterflow virtual impactor (CVI) and a cloud spectrometer and impactor (CSI). The CVI is a fuselage-mounted instrument that samples and sizes cloud droplets and ice crystals between about 8 and 50 micrometers in diameter and evaporates the water, leaving residual particles that can be analyzed to determine the size and composition of the nuclei on which the droplets and crystals formed. The CSI is a new, wing-mounted instrument that measures the mass of condensed water per unit volume of cloud, the droplet-size distribution, and the particle residue. The data provided by these instruments, when compared with the aerosols and CCN measured just outside the cloud, will indicate which of the aerosols participated in cloud formation, the extent to which they were mixed into the cloud, and the degree to which theory enables the prediction of the drop-size distribution on the basis of the CCN activity spectrum. Special attention will be given to large supercooled drops, because these are a major cause of aircraft icing. The research contributes not only to the fundamental understanding of the microphysical structure of supercooled clouds but also to the advancement of aviation safety.

这项赠款支持Twiel博士参与Airs II项目（第二联盟结冰研究），这是美国，加拿大，加拿大，欧洲机构和机构的合作，这是由飞机结冰的重要实践问题所激发的。 AIRS Field计划计划于2003 - 2004年冬季，位于加拿大蒙特利尔以北的Mirabel机场，那里将找到一个地面观测网络和基于地面的遥感设备。 Twiphy博士和她的同事将负责在俄亥俄州克利夫兰运营的NSF C-130飞机上的云微物理观测。 主要科学目标是解释在可能包含冰晶的云中可以形成并继续存在的超冷滴区域的环境。 C-130将配备用于测量云的水含量和冰含量；冰晶的浓度，大小，习惯和密度；冰形核的浓度；云凝结核（CCN）的活性谱；以及在项目区域内和在感兴趣云形成的空气中的气溶胶颗粒的浓度和特性。 Twiphy博士将负责两种仪器，即逆流虚拟影响器（CVI）和云光谱仪和影响器（CSI）。 CVI是一种机身安装的仪器，对云滴和冰晶的尺寸在大约8至50微米之间的直径之间，并蒸发水，留下可以分析的残留颗粒，以确定核的大小和组成，这些粒子的大小和成分和晶体形成。 CSI是一种新型的机翼仪器，可测量每单位云，液滴大小分布和颗粒残基的凝结水的质量。 与在云外测量的气溶胶和CCN相比，这些仪器提供的数据将表明哪些气溶胶参与云形成，它们被混合到云中的程度以及理论能够使理论启用的程度基于CCN活性谱的滴度分布的预测。 将特别注意大型超冷滴，因为这些是飞机糖霜的主要原因。 该研究不仅有助于对超冷云的微物理结构的基本理解，还为航空安全的发展做出了贡献。