EAS Seminar: Fangqun Yu (UAlbany)

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From Contrail Mitigation to Climate Intervention: Insights from Advanced Particle Microphysics

Contrail mitigation and climate intervention are two separate but related emerging challenges our society faces. Aviation accounts for ~ 3.5% of anthropogenic climate forcing (with roughly two-thirds driven by non-CO2 effects, predominantly contrail cirrus), and aviation industry is actively seeking methods for contrail mitigation as air traffic is projected to increase by a factor of ~3.8 from 2018 to 2050. Concurrently, climate intervention via solar radiation modification—particularly stratospheric aerosol injection (SAI)—is being investigated as a potential approach to temporarily reduce global warming and associated risks while net-zero emissions and carbon dioxide removal technologies are scaled up.

This seminar showcases how advanced particle microphysics provide important insights into both challenges. It highlights the critical role of volatile particles formed on jet-engine chemi-ions in contrail mitigation (especially for modern lean-burn engines) and ambient ions from cosmic ray ionization in mediating new particle formation for potential SO2 and H2S SAI strategies. Interestingly, active field measurements in aircraft plumes driven by contrail mitigation efforts can be used to inform and constrain SAI research, which currently lacks robust in-situ data. Furthermore, global simulations incorporating size-resolved advanced particle microphysics indicate radiative efficacies of sulfur-based SAI to be substantially different from previous studies, underscoring the necessity of identifying sources of difference and improved representation of aerosol microphysics in global climate models.

Bio: Fangqun Yu is a tenured senior research faculty of the Atmospheric Sciences Research Center at the State University of New York at Albany. The research areas of his group include the formation of particles and contrails in aircraft plumes, theories of new particle formation in the atmosphere, regional and global modeling of size-resolved (sectional) particle microphysics, aerosol-cloud-precipitation interactions, aerosol direct and indirect radiative forcing, and health effects of ultrafine particles. Since 2023, his team has been working closely with the aviation industry on contrail mitigation. He received the 2024 University at Albany President's Excellence in Research and Creative Activities Award, and was one of four faculty members tapped for 'Pathbreaking Research' Talks on the final day of UAlbany's Research & Entrepreneurship Week in 2025. So far, he has authored or co-authored about 190 peer-reviewed papers with a Google Scholar h-index of 61 and i10-index of 162. According to a Stanford University study published annually through Elsevier, he has been on the list of world's top 2% researchers every year since 2022.