Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine

• Published in: Atmospheric Chemistry and Physics
• Main Authors: M. K. Rotermund, V. Bense, M. P. Chipperfield, A. Engel, J.-U. Grooß, P. Hoor, T. Hüneke, T. Keber, F. Kluge, B. Schreiner, T. Schuck, B. Vogel, A. Zahn, K. Pfeilsticker
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: Physics; QC1-999; Chemistry; QD1-999; Norwegian Sea; Rigby; North Atlantic
• Online Access: https://doi.org/10.5194/acp-21-15375-2021; https://doaj.org/article/03ccca17c5ea4c1caedb56421e2b5bce

We report on measurements of total bromine ( Br tot ) in the upper troposphere and lower stratosphere taken during 15 flights with the German High Altitude and LOng range research aircraft (HALO). The research campaign WISE (Wave-driven ISentropic Exchange) included regions over the North Atlantic, Norwegian Sea, and northwestern Europe in fall 2017. Br tot is calculated from measured total organic bromine ( Br org ) added to inorganic bromine ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">Br</mi><mi>y</mi><mi mathvariant="normal">inorg</mi></msubsup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="31pt" height="18pt" class="svg-formula" dspmath="mathimg" md5hash="e88d8aeec27451686ce7641dc343d6a9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-15375-2021-ie00001.svg" width="31pt" height="18pt" src="acp-21-15375-2021-ie00001.png"/></svg:svg> ), evaluated from measured BrO and photochemical modeling. Combining these data, the weighted mean [ Br tot ] is 19.2±1.2 ppt in the northern hemispheric lower stratosphere (LS), in agreement with expectations for Br tot in the middle stratosphere ( Engel and Rigby et al. , 2018 ). The data reflect the expected variability in Br tot in the LS due to variable influx of shorter lived brominated source and product gases from different regions of entry. A closer look into Br org and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">Br</mi><mi>y</mi><mi mathvariant="normal">inorg</mi></msubsup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="31pt" height="18pt" class="svg-formula" dspmath="mathimg" ...