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.
