Airborne measurements of organic bromine compounds in the Pacific tropical tropopause layer
Navarro, Maria A
Ashfold, Matthew J
Manning, Alistair J
Cuevas, Carlos A
Brominated compounds at the tropical tropopause
Proceedings of the National Academy of Sciences (PNAS)
National Academy of Sciences
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Navarro, M. A., Atlas, E., Saiz-Lopez, A., Rodriguez-Lloveras, X., Kinnison, D., Lamarque, J., Tilmes, S., et al. (2015). Airborne measurements of organic bromine compounds in the Pacific tropical tropopause layer. Proceedings of the National Academy of Sciences (PNAS), 112 13789-13793. https://doi.org/10.1073/pnas.1511463112
Very short-lived brominated substances (VSLBr) are an important source of stratospheric bromine, an effective ozone-destruction catalyst. However, the accurate estimation of the organic and inorganic partitioning of bromine and the input to the stratosphere remains uncertain. Here, we report near-tropopause measurements of organic brominated substances found over the Tropical Pacific during the NASA ATTREX campaigns. We combine aircraft observations and a chemistry-climate model to quantify the total bromine loading injected to the stratosphere. Surprisingly, despite differences in vertical transport between the Eastern and Western Pacific, VSLBr (organic + inorganic) contribute approximately similar amounts of bromine (~6 (4-9) ppt) to the stratospheric input at the tropical tropopause. These levels of bromine cause substantial ozone depletion in the lower stratosphere, and any increases in future abundances (e.g. as a result of aquaculture) will lead to larger depletions.
Bromine, ATTREX, Tropopause
This work was supported by NASA Grant NNX10AO83A S08 and NERC Grant NE/J006246/1. The National Center for Atmospheric Research (NCAR) is funded by the National Science Foundation NSF. Computing resources (ark:/85065/d7wd3xhc) were provided by the Climate Simulation Laboratory at NCAR’s Computational and Information Systems Laboratory (CISL), sponsored by the NSF and other agencies. The CESM project (which includes CAM-Chem) is supported by the NSF and the Office of Science (BER) of the US Department of Energy. This work was also sponsored by the NASA Atmospheric Composition Modeling and Analysis Program Activities (ACMAP), grant/cooperative agreement number NNX11AH90G.
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External DOI: https://doi.org/10.1073/pnas.1511463112
This record's URL: https://www.repository.cam.ac.uk/handle/1810/251368