1Alfred Wegener Institute, Potsdam, Germany
2Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, UK
*now at: Department of Geosciences, Princeton University, New Jersey, USA
Received: 11 Sep 2010 – Discussion started: 18 Oct 2010
Abstract. We evaluate the sensitivity of Bry entering the stratosphere with a simplified model that allows calculations over a wide parameter range for parameters that are currently poorly quantified. The model examines the transport process uncertainties in the source concentrations and lifetimes, in the convective parameterization and in the inorganic bromine washout process due to dehydration. Source concentrations at the surface and lifetimes were found to have a slight effect on the resultant Bry (1 ppt), however this was highly dependent upon, with increasing significance, the BL component of convectively delivered air. Efficiency of convective delivery of boundary layer (BL) air to the tropical tropopause layer (TTL) along with washout at the CPT were found to substantially affect Bry at 400 K – altering the delivered Bry by 3.3 ppt and 2.9 ppt, respectively. We find that the results critically depend on free tropospheric bromine source gas concentrations due to dilution of convective updrafts, and the processes that control free tropospheric bromine source gas concentrations require further attention.
Revised: 21 Jan 2011 – Accepted: 09 Feb 2011 – Published: 16 Feb 2011
Schofield, R., Fueglistaler, S., Wohltmann, I., and Rex, M.: Sensitivity of stratospheric Bry to uncertainties in very short lived substance emissions and atmospheric transport, Atmos. Chem. Phys., 11, 1379-1392, doi:10.5194/acp-11-1379-2011, 2011.