Modeling the Sulfate Aerosol Evolution After Recent Moderate Volcanic Activity, 2008-2012
Name
JGR Atmospheres - 2021 - Brodowsky - Modeling the Sulfate Aerosol Evolution After Recent Moderate Volcanic Activity 2008.pdf
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2.4 MB
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Author(s)
Brodowsky, Christina
Sukhodolov, Timof
Feinb, Aryeh
Höpfner, Michael
Peter, Thomas
Stenke, Andrea
Rozanov, Eugene
Date Issued
November 18, 2021
Journal
Journal of Geophysical Research: Atmospheres
Publisher
American Geophysical Union
Citation
Brodowsky, C., Sukhodolov, T., Feinberg, A., Höpfner, M., Peter, T., Stenke, A., & Rozanov, E. (2021). Modeling the sulfate aerosol evolution after recent moderate volcanic activity, 2008–2012. Journal of Geophysical Research: Atmospheres, 126, e2021JD035472.
Version
Final published version
Abstract
Volcanic activity is a major natural climate forcing and an accurate representation of volcanic aerosols in global climate models is essential. This is a complex task involving many uncertainties in the model design and setup and observations. We analyze the performance of the aerosol-chemistry-climate model SOCOL-AERv2 for three medium-sized volcanic eruptions. We focus on the impact of differences in volcanic plume height and SO2 estimates on the stratospheric aerosol burden. The influence of internal model variability and dynamics are addressed through an ensemble of free-running and nudged simulations at different vertical resolutions. Comparing the modeled evolution of the stratospheric aerosol loading to satellite measurements reveals a good model performance. However, a conclusive validation is complicated by uncertainties in observations and emission estimates. The large spread in emitted sulfur amount and its vertical distribution consequently lead to differences in simulated aerosol burdens. Varying tropopause heights among free-running simulations add to these differences, modulating the amount of sulfur injected into the stratosphere. In nudged mode, volcanic aerosol burden peaks are well reproduced, however changes in convection and clouds affect SO2 oxidation paths and cross-tropopause transport, leading to increased background burdens compared to observations. This effect can be reduced by leaving temperatures unconstrained. A higher vertical resolution of 90 levels increases the stratospheric residence time of sulfate aerosol by reducing the diffusion out of the tropical reservoir. We conclude that the model set-up (vertical resolution and free-running vs. nudged) as well as forcing parameters (volcanic emission strength and plume height) contribute equally to the model uncertainties.
MIT Department
Massachusetts Institute of Technology. Institute for Data, Systems, and Society
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Creative Commons Attribution
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DOI of Published Version
https://doi.org/10.1029/2021JD035472
