Abstract
Abstract. During the recent SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere) project an extensive data set of all halogen species relevant for the atmospheric budget of total organic bromine was collected in the western Pacific region using the Falcon aircraft operated by the German Aerospace agency DLR (Deutsches Zentrum für Luft- und Raumfahrt) covering a vertical range from the planetary boundary layer up to the ceiling altitude of the aircraft of 13 km. In total, more than 700 measurements were performed with the newly developed fully automated in situ instrument GHOST-MS (Gas chromatograph for the Observation of Tracers – coupled with a Mass Spectrometer) by the Goethe University of Frankfurt (GUF) and with the onboard whole-air sampler WASP with subsequent ground-based state-of-the-art GC / MS analysis by the University of East Anglia (UEA). Both instruments yield good agreement for all major (CHBr3 and CH2Br2) and minor (CH2BrCl, CHBrCl2 and CHBr2Cl) VSLS (very short-lived substances), at least at the level of their 2σ measurement uncertainties. In contrast to the suggestion that the western Pacific could be a region of strongly increased atmospheric VSLS abundance (Pyle et al., 2011), we found only in the upper troposphere a slightly enhanced amount of total organic bromine from VSLS relative to the levels reported in Montzka and Reimann et al. (2011) for other tropical regions. From the SHIVA observations in the upper troposphere, a budget for total organic bromine, including four halons (H-1301, H-1211, H-1202, H-2402), CH3Br and the VSLS, is derived for the level of zero radiative heating (LZRH), the input region for the tropical tropopause layer (TTL) and thus also for the stratosphere. With the exception of the two minor VSLS CHBrCl2 and CHBr2Cl, excellent agreement with the values reported in Montzka and Reimann et al. (2011) is found, while being slightly higher than previous studies from our group based on balloon-borne measurements.
Highlights
Bromine atoms are very efficient catalysts in destroying stratospheric ozone
Even the ranges observed with the GHOST and whole-air sampling system (WASP) instruments during SHIVA and the range given in Montzka and Reimann et al (2011) do not overlap
The independent observations of very short-lived substances (VSLS) derived from the two instruments show very good agreement within the 2σ measurement uncertainty over the whole overlapping vertical range of both instruments
Summary
Bromine atoms are very efficient catalysts in destroying stratospheric ozone. On average bromine atoms are more effective by a factor of 64 than chlorine atoms in destroying ozone in the altitude range from 10 to 50 km (Sinnhuber et al, 2009). The fate of the organic and inorganic product gases from the degradation of brominated VSLS in the upper tropical troposphere and TTL is still largely unknown as so far no observations of these are available in this region of the atmosphere. Hossaini et al (2013) used their 3-D chemical transport model to evaluate a range of different emission inventories (Warwick et al, 2006; Liang et al, 2010; Ziska et al, 2013) For this purpose the model outputs for the different emission inventories were compared to independent atmospheric observations including the SHIVA aircraft data, and revealed that significant differences in these scenarios exist for many geographical regions including the western Pacific region. PBL sampling, vertical transport by shallow convection Northeastern coast of Borneo
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
