Evaluating global emission inventories of biogenic bromocarbons
Item
Title (Dublin Core)
Evaluating global emission inventories of biogenic bromocarbons
Description (Dublin Core)
Emissions of halogenated very short-lived substances (VSLS) are poorly constrained. However, their inclusion in global models is required to simulate a realistic inorganic bromine (Br<sub>y</sub>) loading in both the troposphere, where bromine chemistry perturbs global oxidising capacity, and in the stratosphere, where it is a major sink for ozone (O<sub>3</sub>). We have performed simulations using a 3-D chemical transport model (CTM) including three <i>top-down</i> and a single <i>bottom-up</i> derived emission inventory of the major brominated VSLS bromoform (CHBr<sub>3</sub>) and dibromomethane (CH<sub>2</sub>Br<sub>2</sub>). We perform the first concerted evaluation of these inventories, comparing both the magnitude and spatial distribution of emissions. For a quantitative evaluation of each inventory, model output is compared with independent long-term observations at National Oceanic and Atmospheric Administration (NOAA) ground-based stations and with aircraft observations made during the NSF (National Science Foundation) HIAPER Pole-to-Pole Observations (HIPPO) project. For CHBr<sub>3</sub>, the mean absolute deviation between model and surface observation ranges from 0.22 (38%) to 0.78 (115%) parts per trillion (ppt) in the tropics, depending on emission inventory. For CH<sub>2</sub>Br<sub>2</sub>, the range is 0.17 (24%) to 1.25 (167%) ppt. We also use aircraft observations made during the 2011 Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere (SHIVA) campaign, in the tropical western Pacific. Here, the performance of the various inventories also varies significantly, but overall the CTM is able to reproduce observed CHBr<sub>3</sub> well in the free troposphere using an inventory based on observed sea-to-air fluxes. Finally, we identify the range of uncertainty associated with these VSLS emission inventories on stratospheric bromine loading due to VSLS (Br<sub>y</sub><sup>VSLS</sup>). Our simulations show Br<sub>y</sub><sup>VSLS</sup> ranges from ~4.0 to 8.0 ppt depending on the inventory. We report an optimised estimate at the lower end of this range (~4 ppt) based on combining the CHBr<sub>3</sub> and CH<sub>2</sub>Br<sub>2</sub> inventories which give best agreement with the compilation of observations in the tropics.
Creator (Dublin Core)
Hossaini, R.
Mantle, H.
Chipperfield, M. P.
Montzka, S. A.
Hamer, P.
Ziska, F.
Quack, B.
Krüger, K.
Tegtmeier, S.
Atlas, E.
Sala, S.
Engel, A.
Bönisch, H.
Keber, T.
Oram, D.
Mills, G.
Ordóñez, C.
Saiz-Lopez, A.
Warwick, N.
Liang, Q.
Feng, W.
Moore, F.
Miller, B. R.
Marécal, V.
Richards, N. A. D.
Dorf, M.
Pfeilsticker, K.
Date (Dublin Core)
2018-11-01
Type (Dublin Core)
info:eu-repo/semantics/Text
Format (Dublin Core)
info:eu-repo/semantics/application/pdf
Identifier (Dublin Core)
10.5194/acp-13-11819-2013
https://acp.copernicus.org/articles/13/11819/2013/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
Relation (Dublin Core)
info:eu-repo/grantAgreement/EC/FP7/226224
Rights (Dublin Core)
info:eu-repo/semantics/openAccess
