Rapid scrubbing of sulfur dioxide during explosive volcanic eruptions

• Applicants: Professor Dr. Yan Lavallée; Dr. Jérémie Vasseur
• Subject Area: Mineralogy, Petrology and Geochemistry ; Atmospheric Science
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 540863172

This project aims to develop a comprehensive model to constrain syn-eruptive sulfur scrubbing from volcanic ash to enable accurate determination of the sulfur dioxide budget of large explosive eruptions. Volcanic eruptions are one of the most important emitters of sulfur dioxide (Robock, 2000), ultimately responsible for volcanic-climate forcing over timescales from months to years (Bluth et al., 1992; Robock, 2000) or even decades to millennia (Baldini et al., 2015). Recent evidence shows that hot volcanic ash can scrub sulfur dioxide from a plume rapidly, sequestering sulfur into fast-growing solid sulfate salts on particle surfaces (Ayris et al., 2013; Delmelle et al., 2018; Renggli and King, 2018; Casas et al., 2019), preventing abundant portions of the erupted sulfur from entering the atmosphere and be detected by gas monitoring methods. Therefore, an unconstrained fraction of the total volcanic sulfur budget is currently ‘missing’ from calculations and measurements. The sulfur budget needs to be accurately constrained so that the community can: (1) predict atmospheric sulfur dioxide injection for explosive eruptions, past or future, to enable their climate impacts to be determined; (2) quantify ‘missing’ sulfur dioxide for instrumentally observed eruptions to inform models of triggering processes in the crustal reservoir. This project will provide new transformative experimental constraints to quantify scrubbing rates for volcanic ash across the compositional spectrum and develop a novel numerical model to quantify sulfur dioxide budget and partitioning for explosive eruptions from VEI 4 to 8.

• DFG Programme: Research Grants