Title Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn
Author Martinerie, P.; Nourtier-Mazauric, E.; Barnola, J.M.; Sturges, W.T.; Worton, D.R.; Atlas, E.; Gohar, L.K.; Shine, K.P.; Brasseur, G.P.
Author Affil Martinerie, P., Université Joseph Fourier-Grenoble, Laboratoire de Glaciologie et Géophysique de l'Environnement, Saint Martin d'Heres, France. Other: University of East Anglia, United Kingdom; Rosenstiel School of Marine and Atmospheric Science; University of Reading, United Kingdom; National Center for Atmospheric Research
Source Atmospheric Chemistry and Physics, 9(12), p.3911-3934, . Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2009
Notes In English. Includes supplement: http://www.atmos-chem- phys.net/9/3911/2009/acp-9-3911-2009- supplement.pd f; published in Atmospheric Chemistry and Physics Discussions: 13 January 2009, http://www.atmos-chem-phys- discuss.net/9/991/2009/acpd-9-991-2009.html; accessed in Apr., 2011. 62 refs. Ant. Acc. No: 91574. GeoRef Acc. No: 310573
Index Terms atmospheric boundary layer; boundary layer; firn; geochemistry; polar regions; polar atmospheres; simulation; stratosphere; Canada--Devon Island; Antarctica--Dome C; Greenland; polar regions; Antarctica--Queen Maud Land; Antarctica; Arctic region; atmosphere; Berkner Island; Canada; carbon tetrachloride; chlorinated hydrocarbons; chlorofluorocarbons; climate forcing; Devon Island; Dome C; greenhouse gases; halogenated hydrocarbons; numerical models; Nunavut; organic compounds; photochemistry; Queen Elizabeth Islands; Queen Maud Land; solar forcing; sulfur hexafluoride; troposphere; two-dimensional models; Wilkes Land
Abstract The budgets of seven halogenated gases (CFC-11, CFC-12, CFC-113, CFC-114, CFC-115, CCl4 and SF6) are studied by comparing measurements in polar firn air from two Arctic and three Antarctic sites, and simulation results of two numerical models: a 2-D atmospheric chemistry model and a 1-D firn diffusion model. The first one is used to calculate atmospheric concentrations from emission trends based on industrial inventories; the calculated concentration trends are used by the second one to produce depth concentration profiles in the firn. The 2-D atmospheric model is validated in the boundary layer by comparison with atmospheric station measurements, and vertically for CFC- 12 by comparison with balloon and FTIR measurements. Firn air measurements provide constraints on historical atmospheric concentrations over the last century. Age distributions in the firn are discussed using a Green function approach. Finally, our results are used as input to a radiative model in order to evaluate the radiative forcing of our target gases. Multi-species and multi-site firn air studies allow to better constrain atmospheric trends. The low concentrations of all studied gases at the bottom of the firn, and their consistency with our model results confirm that their natural sources are small. Our results indicate that the emissions, sinks and trends of CFC-11, CFC-12, CFC-113, CFC-115 and SF6 are well constrained, whereas it is not the case for CFC-114 and CCl4. Significant emission-dependent changes in the lifetimes of halocarbons destroyed in the stratosphere were obtained. Those result from the time needed for their transport from the surface where they are emitted to the stratosphere where they are destroyed. Efforts should be made to update and reduce the large uncertainties on CFC lifetimes.
URL http://www.atmos-chem-phys.net/9/3911/2009/acp-9-3911-2009.pdf
Publication Type journal article
Record ID 65007028