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https://egusphere.copernicus.org/preprints/2024/egusphere-2023-3041/ *Authors* Hunter York Brown, Benjamin Wagman, Diana Bull, Kara Peterson, Benjamin Hillman, Xiaohong Liu, Ziming Ke, and Lin Lin *04 Jan 2024* *How to cite*. Brown, H. Y., Wagman, B., Bull, D., Peterson, K., Hillman, B., Liu, X., Ke, Z., and Lin, L.: Validating a microphysical prognostic stratospheric aerosol implementation in E3SMv2 using the Mount Pinatubo eruption, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2023-3041, 2024. *Abstract* This paper describes the addition of a stratospheric prognostic aerosol (SPA) capability – developed with the goal of accurately simulating aerosol formation following explosive volcanic eruptions – in the Department of Energy (DOE) Earth Energy Exascale Model, version 2 (E3SMv2). The implementation includes changes to the 4-mode Modal Aerosol Module microphysics in the stratosphere to allow for larger particle growth and more accurate stratospheric aerosol lifetime following the Mt. Pinatubo eruption. E3SMv2-SPA reasonably reproduces stratospheric aerosol lifetime, burden, and aerosol optical depth when compared to remote sensing observations and the interactive chemistry-climate model, CESM2-WACCM. *Global stratospheric aerosol size distributions identify the nucleation and growth of sulfate aerosol from volcanically injected SO2 from both major and minor volcanic eruptions from 1991 to 1993. *Modeled aerosol effective radius is consistently lower than satellite and in-situ measurements (max differences of ~30 %). Comparisons with in-situ size distribution samples indicate that this underestimation is due to both E3SMv2-SPA and CESM2-WACCM simulating too small of accumulation and coarse mode aerosol 6–18 months post-eruption, with E3SMv2-SPA simulating ~50 % the coarse mode geometric mean diameters of observations 11 months post-eruption. Effective radii from the models and observations are used to calculate offline scattering and absorption efficiencies to explore the implications of smaller simulated aerosol size on the Mt. Pinatubo climate impacts. Scattering efficiencies at wavelengths of peak solar irradiance (~0.5 µm) are 10–80 % higher for daily samples in models relative to observations through 1993, suggesting higher diffuse radiation at the surface and a larger cooling effect in the models. Absorption efficiencies at the peak wavelengths of outgoing terrestrial radiation (~10 µm) are 15–40 % lower for daily samples in models relative to observations suggesting an underestimation in stratospheric heating in the models. The similar performance of CESM2-WACCM and E3SMv2-SPA makes E3SMv2-SPA a viable alternative to simulating climate impacts from stratospheric sulfate aerosols. *Source: EGU Sphere* -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/CAHJsh9_tBLOFq9ZXyJ%2BVfE62uysj%2BUbboeqT%3DUPggNKyKWWzng%40mail.gmail.com.
