Global observations of tropospheric BrO columns using GOME-2 satellite data 1Belgian Institute for Space Aeronomy (IASB-BIRA), Brussels, Belgium
25 Feb 2011
2National Centre for Atmospheric Science (NCAS), Cambridge, CB2 1EW, UK
3Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
4Institute of Environmental Physics, University of Bremen, Bremen, Germany
5National Institute of Water and Atmospheric Research (NIWA), Omakau, Central Otago, New Zealand
Received: 08 October 2010 – Published in Atmos. Chem. Phys. Discuss.: 22 November 2010 Abstract. Measurements from the GOME-2 satellite instrument have been analyzed for
tropospheric BrO using a residual technique that combines measured BrO
columns and estimates of the stratospheric BrO content from a climatological
approach driven by O3 and NO2 observations. Comparisons between the
GOME-2 results and BrO vertical columns derived from correlative ground-based
and SCIAMACHY nadir observations, present a good level of consistency. We
show that the adopted technique enables separation of stratospheric and
tropospheric fractions of the measured total BrO columns and allows
quantitative study of the BrO plumes in polar regions. While some satellite
observed plumes of enhanced BrO can be explained by stratospheric descending
air, we show that most BrO hotspots are of tropospheric origin, although they
are often associated to regions with low tropopause heights as well.
Elaborating on simulations using the p-TOMCAT tropospheric chemical
transport model, this result is found to be consistent with the mechanism of
bromine release through sea salt aerosols production during blowing snow
events. No definitive conclusion can be drawn however on the importance of
blowing snow sources in comparison to other bromine release mechanisms.
Outside polar regions, evidence is provided for a global tropospheric BrO
background with column of 1–3 × 1013 molec cm−2,
consistent with previous estimates.
Revised: 17 February 2011 – Accepted: 20 February 2011 – Published: 25 February 2011
Citation: Theys, N., Van Roozendael, M., Hendrick, F., Yang, X., De Smedt, I., Richter, A., Begoin, M., Errera, Q., Johnston, P. V., Kreher, K., and De Mazière, M.: Global observations of tropospheric BrO columns using GOME-2 satellite data, Atmos. Chem. Phys., 11, 1791-1811, doi:10.5194/acp-11-1791-2011, 2011.