Impact of very short-lived halogens on stratospheric ozone abundance and UV radiation in a geo-engineered atmosphere S. Tilmes1, D. E. Kinnison1, R. R. Garcia1, R. Salawitch2, T. Canty2, J. Lee-Taylor1, S. Madronich1, and K. Chance3 1National Center for Atmospheric Research, Boulder, Colorado, USA 2University of Maryland College Park, MD, USA 3Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
Abstract. The impact of very short-lived (VSL) halogenated source species on the ozone
layer and surface erythemal ultraviolet radiation (UVERY) 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
UVERY due to geo-engineering for nearly all seasons and
latitudes, with UVERY rising by 12% and 6% in southern
and northern high latitudes, respectively. When VSL halogen sources are
neglected, future UVERY increases due to declines in ozone
column are nearly balanced by reductions of UVERY 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 UVERY 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.
Citation: Tilmes, S., Kinnison, D. E., Garcia, R. R., Salawitch, R., Canty, T., Lee-Taylor, J., Madronich, S., and Chance, K.: Impact of very short-lived halogens on stratospheric ozone abundance and UV radiation in a geo-engineered atmosphere, Atmos. Chem. Phys., 12, 10945-10955, doi:10.5194/acp-12-10945-2012, 2012.