ACP Atmospheric Chemistry and Physics ACP Atmos. Chem. Phys. 1680-7324 Copernicus Publications Göttingen, Germany 10.5194/acp-12-10945-2012 Impact of very short-lived halogens on stratospheric ozone abundance and UV radiation in a geo-engineered atmosphere Tilmes S. 1 Kinnison D. E. 1 Garcia R. R. 1 Salawitch R. 2 Canty T. 2 Lee-Taylor J. 1 Madronich S. 1 Chance K. 3 National Center for Atmospheric Research, Boulder, Colorado, USA University of Maryland College Park, MD, USA Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA 20 11 2012 12 22 10945 10955 Copyright: © 2012 S. Tilmes et al. 2012 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://acp.copernicus.org/articles/12/10945/2012/acp-12-10945-2012.html The full text article is available as a PDF file from https://acp.copernicus.org/articles/12/10945/2012/acp-12-10945-2012.pdf

The impact of very short-lived (VSL) halogenated source species on the ozone layer and surface erythemal ultraviolet radiation (UV<sub>ERY</sub>) is investigated in the context of geo-engineering of climate by stratospheric sulfur injection. For a projected 2040 model atmosphere, consideration of VSL halogens at their upper limit results in lower ozone columns and higher UV<sub>ERY</sub> due to geo-engineering for nearly all seasons and latitudes, with UV<sub>ERY</sub> rising by 12% and 6% in southern and northern high latitudes, respectively. When VSL halogen sources are neglected, future UV<sub>ERY</sub> increases due to declines in ozone column are nearly balanced by reductions of UV<sub>ERY</sub> due to scattering by the higher stratospheric aerosol burden in mid-latitudes. Consideration of VSL sources at their upper limit tips the balance, resulting in annual average increases in UV<sub>ERY</sub> of up to 5% in mid and high latitudes. Therefore, VSL halogens should be considered in models that assess the impact of stratospheric sulfur injections on the ozone layer.

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