Volcanic eruptions impact the Earth system and society on timescales of weather (days to weeks) to climate (months to years) and are the dominant driver of climate variability over the last millennium. However, volcanic eruptions are most often poorly represented in Earth system models. This project was funded by: NCAR/UCAR Atmospheric Chemistry and Modeling Visiting Scientist Program, NCAS, University of Leeds School of Earth and Environment.

The VolcanEESM project presents a volcanic sulphur dioxide (SO2) emissions database for use in Earth System models. The database provides a comprehensive list of volcanic eruptions that were reported to emitted significant amounts of SO2 from 1850 to present. The presented dataset is instrumental for research using Earth system models that that represent stratospheric aerosols prognostically, including those participating in forthcoming Climate Modelling Inter-comparison Projects.

The project focused on large-magnitude (VEI>4) eruptions, which was used to identify using the Smithsonian Global Volcanism Program database and ice-core data. The total amount of SO2 emitted by an eruption, including the spatial distribution of the volcanic injection, was determined by using parameters that based on analogous eruptions that occurred during the satellite era following the methodology of Stoffel et al. [2015] and Gao et al. [2008].

The project estimated lower and upper bounds of the SO2 emitted and constrained the season by an eruption [similar to Stoffel et al., 2015] and expect the uncertainties on our inventory to be of comparable magnitude to those prescribing the forcing. Before running long model integrations, they assessed the representativeness of the emission inventory and quantified uncertainties by comparing simulated sulphate deposition patterns for selected eruptions to ice-core records and by comparing simulated AOD to Crowley et al. [2008] and Sato et al. [1993]. Where applicable they also compared simulated optical properties to astronomical estimates of atmospheric transmission [Stothers 1996; 2001].