The mass-independent oxygen isotopic composition (O-MIF) - also known as Δ17O - is one powerful tool for studying atmospheric chemical reactions. By applying Δ17O to the study of sulfate and nitrate (and more!), we've been able to observe and quantify atmospheric formation processes in different regions and time periods. 

  This innovative approach has allowed us to identify key processes and fill in important gaps in our understanding of atmospheric chemistry. 

Refs: Hattori et al. 2021 Science Advances; Itahashi, Hattori et al., 2022 ES&T; Ishino, Hattori et al. 2021 JGR-A

  Atmospheric sulfate also has a major impact on the global radiation budget and cloud lifetimes. Despite its importance, our scientific understanding of the climatic and environmental impacts of sulfate aerosols remains low. There are multiple sources of sulfur in the atmosphere, including both human-made and natural sources, and there are many unknowns about the atmospheric chemical reaction processes that contribute to aerosol formation.

  That's where stable isotope composition comes in - it's an effective new tool for tracking the origin of sulfur and understanding the complex atmospheric chemical processes that contribute to sulfate aerosol formation. By studying stable isotopes, we can uncover new insights into the impacts of sulfate on our planet and develop strategies for reducing its negative effects.

Volcanic sulfate works: Gautier et al. 2019 Nature Comm.; Hattori et al., 2013 PNAS

Tropospheric sulfate works: Hattori et al. 2021 Science Advances; Itahashi, Hattori et al., 2022 ES&T

Carbonyl sulfide (COS or OCS) works [Ref: Hattori et al. 2020 PNAS]