%0 Generic
%A Dorf, Marcel
%D 2005
%F heidok:6093
%R 10.11588/heidok.00006093
%T Investigation of Inorganic Stratospheric Bromine using Balloon-Borne DOAS Measurements and Model Simulations
%U https://archiv.ub.uni-heidelberg.de/volltextserver/6093/
%X Inorganic bromine is the second most important halogen effecting stratospheric ozone [WMO2003]. Although the concentration of bromine in the stratosphere is about two orders of magnitude lower than the concentration of chlorine, it currently contributes about 25% to global ozone loss due to its much greater ozone depletion efficiency (factor of around 45) compared to chlorine. In this study, stratospheric balloon-borne DOAS (Differential Optical Absorption Spectroscopy) measurements of bromine-monoxide (BrO) were analysed and interpreted using the 3-D CTM (Chemical Transport Model) SLIMCAT [Chipperfield98] and a 1-D photochemical model. Photochemical changes were calculated along air mass trajectories which match the balloon data with SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite observations in order to produce a set of BrO profiles suitable for SCIAMACHY validation. Furthermore, DOAS BrO observations were used to infer the trend of total inorganic stratospheric bromine, which peaked around 1998 at (21+-3) pptv and is consistently 3.5 to 5 pptv higher than the known trend in organic bromine precursors (halons and methyl bromide) can account for. This discrepancy, the non-zero amount of inorganic bromine observed around the tropopause and the rapid increase above the tropopause, all indicate that short-lived organic bromine source gases have to be taken into account. These results were confirmed by comparing the DOAS BrO data with different SLIMCAT model runs. Moreover, previous discrepancies between DOAS OClO measurements and model comparisons [Fitzenberger00b] were removed and detailed model studies were used to investigate ozone loss on specific days and the consistency of the known stratospheric photochemistry.