Secondary Marine Aerosol precursors and Links to aerosol growth at ice-melT onset in the Arctic (SMALTA)

Colorado State University, Fort Collins CO

Investigators

Abstract

The goal of this project is to advance knowledge about the formation of secondary marine aerosol in the atmosphere. Compared to primary marine aerosol, secondary aerosol explains a larger fraction of variability in marine cloud condensation nuclei and cloud droplet number concentrations. This work is expected to improve the predictive understanding of ocean - atmosphere interactions that control aerosol number and properties over remote oceans and will improve the mechanistic understanding of the formation of marine cloud condensation nuclei. The results will provide needed information for improved model representation of aerosol impacts on marine cloud properties and Earth’s changing climate. Measurements of volatile organic compounds will be made during the Atmospheric Rivers and the Onset of Sea Ice Melt (ARTofMELT) project aboard IB Oden, in May – June 2023. New measurements of oxygenated volatile organic compounds will allow a determination of whether oxygenated monoterpenes, linear carbonyls and phenolic compounds are important contributors to gas-phase marine reactive organic carbon in a polar marine region. In addition, new measurements of reduced sulfur compounds will allow a determination about whether methanethiol makes an important contribution to the natural sulfur budget during the Atlantic Arctic spring bloom. Finally, gas-aerosol closure simulations will quantify the role of these under-explored precursors of secondary marine aerosol in controlling aerosol properties. The observations and modeling of this project have relevance to marine regions beyond the Arctic, where (1) models of aerosol properties have relied on assumptions about the nature and identity of secondary marine aerosol precursors, and (2) efforts to reach closure between measured and predicted oxidant reactivity have indicated a missing source of reactive organic carbon. Three graduate students will participate in the internationally collaborative research. A collaboration with the Natural Sciences Education and Outreach Center at Colorado State University will involve the design of hands-on and student-driven classroom activities that focus on greenhouse gases and their impacts on both local agricultural systems, and remote ocean and polar ecosystems. 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.