TY - JOUR
T1 - The contribution of natural and anthropogenic very short-lived species to stratospheric bromine
AU - Hossaini, R.
AU - Chipperfield, M. P.
AU - Feng, W.
AU - Breider, T. J.
AU - Atlas, E.
AU - Montzka, S. A.
AU - Miller, B. R.
AU - Moore, F.
AU - Elkins, J.
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012
Y1 - 2012
N2 - We have used a global three-dimensional chemical transport model to quantify the impact of the very short-lived substances (VSLS) CHBr 3, CH 2Br 2, CHBr 2Cl, CHBrCl 2, CH 2BrCl and C 2H 5-Br on the bromine budget of the stratosphere. Atmospheric observations of these gases allow constraints on surface mixing ratios that, when incorporated into our model, contribute ∼4.9-5.2 parts per trillion (ppt) of inorganic bromine (Br y) to the stratosphere. Of this total, ∼76 % comes from naturally-emitted CHBr 3 and CH 2Br 2. The remaining species individually contribute modest amounts. However, their accumulated total accounts for up to ∼1.2 ppt of the supply and thus should not be ignored. We have compared modelled tropical profiles of a range of VSLS with observations from the recent 2009 NSF HIPPO-1 aircraft campaign. Modelled profiles agree reasonably well with observations from the surface to the lower tropical tropopause layer. We have also considered the poorly studied anthropogenic VSLS, C 2H 5Br, CH 2BrCH 2Br, n-C 3H 7Br and i-C 3H 7Br. We find the local atmospheric lifetime of these species in the tropical tropopause layer are ∼183, 603, 39 and 49 days, respectively. These species, particularly C 2H 5Br and CH 2BrCH 2Br, would thus be important carriers of bromine to the stratosphere if emissions were to increase substantially. Our model shows ∼70-73 % and ∼80-85 % of bromine from these species in the tropical boundary layer can reach the lower stratosphere.
AB - We have used a global three-dimensional chemical transport model to quantify the impact of the very short-lived substances (VSLS) CHBr 3, CH 2Br 2, CHBr 2Cl, CHBrCl 2, CH 2BrCl and C 2H 5-Br on the bromine budget of the stratosphere. Atmospheric observations of these gases allow constraints on surface mixing ratios that, when incorporated into our model, contribute ∼4.9-5.2 parts per trillion (ppt) of inorganic bromine (Br y) to the stratosphere. Of this total, ∼76 % comes from naturally-emitted CHBr 3 and CH 2Br 2. The remaining species individually contribute modest amounts. However, their accumulated total accounts for up to ∼1.2 ppt of the supply and thus should not be ignored. We have compared modelled tropical profiles of a range of VSLS with observations from the recent 2009 NSF HIPPO-1 aircraft campaign. Modelled profiles agree reasonably well with observations from the surface to the lower tropical tropopause layer. We have also considered the poorly studied anthropogenic VSLS, C 2H 5Br, CH 2BrCH 2Br, n-C 3H 7Br and i-C 3H 7Br. We find the local atmospheric lifetime of these species in the tropical tropopause layer are ∼183, 603, 39 and 49 days, respectively. These species, particularly C 2H 5Br and CH 2BrCH 2Br, would thus be important carriers of bromine to the stratosphere if emissions were to increase substantially. Our model shows ∼70-73 % and ∼80-85 % of bromine from these species in the tropical boundary layer can reach the lower stratosphere.
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U2 - 10.5194/acp-12-371-2012
DO - 10.5194/acp-12-371-2012
M3 - Article
AN - SCOPUS:84855948162
VL - 12
SP - 371
EP - 380
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
SN - 1680-7316
IS - 1
ER -