Collaborative Research: United States University CLOUD (Cosmics Leaving OUtdoor Droplets) Consortium Membership

该项目将支持卡内基梅隆大学、加州理工学院和科罗拉多大学博尔德分校继续加入欧洲核子研究中心的CLOUD联盟，研究驱动地球大气中新粒子形成和生长的化学和物理。CLOUD是一个最先进的26立方米的不锈钢室，可以精确控制温度和相对湿度。CLOUD的新研究将侧重于研究产生极低挥发性有机化合物的化学机制，这些有机化合物能够成核并凝结在新成核的颗粒上。目标环境包括自然（森林和海洋）和污染（城市）条件，以及自由对流层的低温特征。未来3年的计划研究包括：(1)在自由对流层条件下发现的第一代有机氧化产物的老化；(2)有机氧化和无机硫、氮、碘氧化中关键自由基中间体的测量和建模，以及有机和无机系统之间的相互作用；(3)测量和模拟蒸汽与10 nm以下带电粒子和中性粒子之间的相互作用，以约束关键的微物理术语；(4)将CLOUD结果传播给大气模式，测试其解释现场测量的能力，并了解改进气溶胶辐射强迫模式的意义。除了提供所需的联盟费用外，该项目还将支持参加CLOUD实验活动以及相关的联盟会议和数据研讨会的运输和旅行。与该项目相关的博士和博士后学生（由其他奖项支持）都被整合到一个由学生和高级研究人员组成的国际合作网络中，这些研究人员与一些在气溶胶和大气化学研究方面最受尊敬的科学家一起工作。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will support the continued membership of Carnegie Mellon University, the California Institute of Technology, and the University of Colorado at Boulder in the CLOUD consortium at CERN to study the chemistry and physics that drive new-particle formation and growth in Earth's atmosphere. CLOUD is a state-of-the-art 26 cubic meter stainless-steel chamber with precise control over temperature and relative humidity. The new research at CLOUD will focus on the study of chemical mechanisms that generate extremely low volatility organic compounds capable of nucleating and condensing onto freshly nucleated particles. Target environments include natural (both forest and marine) and polluted (urban) conditions, as well as cold temperatures characteristic of the free troposphere. Planned research over the next 3 years, includes studies of: (1) aging of first-generation organic oxidation products under conditions found in the free troposphere; (2) measurement and modeling of key radical intermediates in organic oxidation and also inorganic sulfur, nitrogen, and iodine oxidation, as well as interaction between organic and inorganic systems; (3) measurement and modeling of interactions among vapors and both charged and neutral particles below 10 nm to constrain key microphysical terms; and (4) propagating CLOUD results to atmospheric models, testing their capability to explain field measurements, and understanding the implications of improvements to models for aerosol radiative forcing. In addition to providing the required consortium fee, this project will support shipping and travel to CLOUD experimental campaigns and associated consortium meetings and data workshops. Both doctoral and postdoctoral students associated with the project (supported by other awards) are integrated into an international collaborative network of students and senior researchers who work with some of the most highly regarded scientists in the study of aerosols and atmospheric chemistry.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.