CAREER: Toward an Understanding of Secondary Aerosol Formation, Particle Ageing in Droplets, and Cloud Processing

气溶胶在空气质量和地球辐射平衡方面发挥着重要作用。气溶胶的有机成分是普遍存在的，但其形成特性还没有得到很好的理解。 已知水相过程影响大气多相系统的组成，并且是二次气溶胶形成的重要途径。 然而，由于云滴中有机气溶胶-水相互作用和过程的非理想性是复杂的;目前的模型不能再现实验室或现场的观测结果。 首席研究员（PI）将开发一种独特的测量能力，通过实验室和现场的云处理来研究二次气溶胶的形成和粒子老化。 在通过连续流流向热梯度室处理之前和之后，将对环境或人工产生的气溶胶进行采样，并使用扫描迁移率粒子分析仪对数量大小分布进行表征，使用高分辨率气溶胶质谱仪对化学成分进行表征。 将测量被激活为云凝结核（CCN）的粒子的分数，作为过饱和度的函数，以及由云处理引起的气溶胶的挥发性、表面张力和其他性质的相应变化。 将开发分离和表征间隙气溶胶和活化液滴以及通过CCN室再循环处理过的气溶胶的方法。 基于这种测量能力的结果将填补关键的空白，在云液滴中清除气溶胶的化学演变的理解。 PI和她的学生将利用加州大学滨江伯恩斯工程学院环境研究与技术中心（CE-CERT）最先进的空气污染实验室的现有设施。 该设施还将为她的研究团队提供与更广泛的研究社区互动的机会。该研究将解决空气质量，气候和健康方面的重要问题并推进知识。 新的测量能力将被纳入一个早期职业PI的长期研究计划，该PI来自地球科学中代表性不足的群体。 作为美国最具种族和经济多样性的公共研究机构之一的教职员工，PI将成为来自广泛背景的学生的榜样和导师。 PI将开发一个综合的研究和教育计划的基础上监督，情景和非正式的指导技术，针对研究生，本科生和K-12学生。 研究生将通过参与研究工作得到支持，并将在科学会议上和通过审查出版物传播研究结果。 该项目还将资助两个本科生研究奖学金，其中一个将针对教育和/或经济背景不利的学生。 PI将继续与当地高中和代表性不足的学生目前的研究指导关系。最后，通过与加州科学项目的合作，PI将为K-12教师提供为期5天的夏季研讨会，重点是气候变化。

Aerosols play an important role in air quality and Earth's radiative balance. Organic constituents of aerosols are ubiquitous but their formation properties are not well understood. Aqueous-phase processes are known to affect the composition of the atmospheric multiphase systems and are an important pathway for secondary aerosol formation. However non-idealities due to organic aerosol-water interactions and processes in cloud droplets are complex; current models do not reproduce observations in the laboratory or field. The principal investigator (PI) will develop a unique measurement capability to investigate secondary aerosol formation and particle ageing via cloud processing in both the laboratory and field. Ambient or artificially generated aerosols will be sampled and characterized for number size distributions with a scanning mobility particle analyzer and chemical composition with a high-resolution aerosol mass spectrometer both before and after processing through a continuous flow stream-wise thermal gradient chamber. The fractions of particles that are activated to cloud-condensation-nuclei (CCN) as a function of supersaturation and corresponding changes in volatility, surface tension, and other properties of aerosols that result from cloud processing will be measured. Methods to separate and characterize interstitial aerosol and activated droplets and to recycle processed aerosols through the CCN chamber will be developed. Results based on this measurement capability will fill critical gaps in understanding of the chemical evolution of aerosol scavenged in cloud droplets. The PI and her students will leverage existing facilities at a state-of-the art air pollution laboratory at the University of California, Riverside Bourns College of Engineering- Center for Environmental Research and Technology (CE-CERT). This facility will also provide opportunities for her research team to interact with the broader research community.The research will address important questions and advance knowledge in air quality, climate, and health. The new measurement capability will be incorporated into the long-term research plans of an early-career PI from an underrepresented group in the geosciences. As a faculty member at one of the most ethnically and economically diverse public research institutions in the United States, the PI will act as a role model and mentor to students from a broad range of backgrounds. The PI will develop an integrated research and education program based on supervisory, situational, and informal mentoring techniques targeting graduate, undergraduate, and K-12 students. Graduate students will be supported through participation in the research effort and will disseminate findings at scientific conferences and via reviewed publications. The project will also fund two undergraduate research fellowships, one of which would target students from educationally and/or economically disadvantaged backgrounds. The PI will continue her current research-mentoring relationships with local high school and underrepresented students. Finally, through collaboration with the California Science Project, the PI will offer 5-day summer workshops for K-12 teachers with a focus on climate change.