Collaborative Research: Impacts of Sulfur Emission Reductions on Wintertime PM2.5 in Fairbanks, Alaska

This research will focus on advancing the understanding of particle acidity in the atmosphere of cold environments and assessing the effects of fuel oil sulfur reductions on particulate sulfur and other species in Alaskan cities. A recent transition to lower-sulfur fuel oil as part of a government-mandated air quality mitigation strategy in Fairbanks and neighboring communities offers a rare opportunity to directly observe and quantify the atmospheric impacts of reduced sulfur emissions. This work advances public health and welfare by guiding national strategies to reduce exposure to fine particulate matter and addressing the unique air quality challenges faced by Arctic communities. The recently NSF-funded 2022 Alaskan Layered Pollution And Chemical Analysis (ALPACA) study in Fairbanks Alaska showed that a substantial portion of PM2.5 sulfur was found in sulfur compounds that are only formed via aqueous-phase chemistry within a narrow pH range. The unique Arctic winter conditions enabled a new understanding of aerosol processes that enhanced heterogeneous chemistry by partitioning gas-phase precursors (e.g., formaldehyde and sulfur dioxide) into the particle phase and influenced particle pH through the temperature-sensitive behavior of key semi-volatile species like ammonia. In this project, real-time monitoring instrumentation will be used to quantify PM2.5 sulfate, hydroxymethanesulfonate, and related sulfur species, while simultaneously characterizing aerosol thermodynamics focusing on liquid water content and acidity under Arctic winter conditions. The inclusion of high time resolution measurements of gas-phase ammonia, nitric acid, and other trace gases will greatly extend beyond ALPACA’s original scope to better understand the processes influencing aerosol composition and acidity. 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. NSF Award ID: 2534331 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Jason St Clair | Institution: University of Maryland Baltimore County, BALTIMORE, MD | Award Amount: $66,154 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2534331 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2534331.html