Impact of very short-lived halogens on stratospheric ozone abundance and UV radiation in a geo-engineered atmosphere 1National Center for Atmospheric Research, Boulder, Colorado, USA
20 Nov 2012
2University of Maryland College Park, MD, USA
3Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
Received: 28 July 2012 – Published in Atmos. Chem. Phys. Discuss.: 27 August 2012 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.
Revised: 07 November 2012 – Accepted: 09 November 2012 – Published: 20 November 2012
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.