Collaborative Research: Coastal Cloud Chemistry during the Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE-CCC)

合作研究：东太平洋云气溶胶降水实验期间的沿海云化学（EPCAPE-CCC）

• 批准号: 2133183
• 负责人: Markus Petters
• 金额: $ 29.88万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2133183&HistoricalAwards=false
• 关键词: Collaborative; Research; Coastal; Cloud; Chemistry

This project is focused on the study of cloud chemistry in support of improvements in how cloud formation is represented in climate models. A suite of advanced chemical measurements will be made at the Scripps Pier and at nearby Mt. Soledad to augment the Department of Energy’s Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) campaign to be conducted in La Jolla California from February 2023 to January 2024. This effort will provide an unprecedented characterization of cloud chemical processing that is expected to help reduce a major uncertainty in climate model predictions.This project adds advanced chemical characterization of clouds to EPCAPE by leveraging recent instrument developments of single-particle mass spectrometry techniques, miniaturized static thermal gradient cloud condensation nuclei (CCN) instruments, and a custom-designed instrument for measuring aqueous hydroxyl (OH) radicals formed in nascent cloud droplets (the OH "burst"). The sampling strategy enables testing of the following hypotheses: (1) The subset of the aerosol population that is activated to cloud droplets is chemically distinct from the unactivated particles, and its size-resolved chemical composition is further differentiated by adding aqueous-oxidized components that can be identified in single-particle mass fragments. The chemical changes lower the activation supersaturation required for subsequent activation of particles, which in turn may affect cloud structure and drop distributions. (2) Gas-phase compounds that are removed by denuding will lower the supersaturation required for activation of each particle by enhancing water solubility during the uptake process. The effect is expected to depend on the amount of pollution influence, on the composition and concentration of gaseous species, and on particle size. (3) Particles with longer times between cloud cycles will produce a larger OH burst, and as a result, larger changes to particle chemical composition during cloud cycling. The OH burst activity, together with the availability of gas phase species will explain much of the variation in the chemical changes observed between cloud events.This effort includes the training of graduate and undergraduate students in instrument maintenance and measurement analyses to prepare the next generation of scientists for conducting atmospheric research.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.

该项目的重点是研究云化学，以支持改进气候模型中云形成的表示方式，将在斯克里普斯码头和附近的索莱达山进行一系列先进的化学测量，以增强能源部东部的能力。太平洋云气溶胶降水实验 (EPCAPE) 活动将于 2023 年 2 月至 2024 年 1 月在加利福尼亚州拉霍亚进行。这项工作将为云化学过程提供前所未有的表征，预计将有助于减少主要的不确定性该项目通过利用单粒子质谱技术、小型静态热梯度云凝核 (CCN) 仪器和定制设计的水羟基测量仪器的最新仪器开发，为 EPCAPE 添加了先进的云化学表征(OH) 自由基在新生云滴中形成（OH“爆发”）。采样策略可以检验以下假设：(1) 被激活的气溶胶群体子集。云滴在化学上与未活化的颗粒不同，并且通过添加可以在单颗粒质量碎片中识别的水氧化成分来进一步区分其尺寸分辨的化学成分，化学变化降低了后续颗粒活化所需的活化过饱和度。 (2) 通过剥蚀去除的气相化合物将通过在吸收过程中增强水溶性来降低活化每个颗粒所需的过饱和度预计该影响取决于污染影响量、气态物质的成分和浓度以及颗粒尺寸 (3) 云周期间隔时间较长的颗粒将产生较大的 OH 爆发。 ，云循环过程中粒子化学成分的较大变化以及气相物种的可用性将解释云事件之间观察到的化学变化的大部分变化。这项工作包括对研究生和本科生进行培训。仪器维护和测量分析，为下一代科学家做好准备这反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。