Title Perfluorocarbons in the global atmosphere; tetrafluoromethane, hexafluoroethane, and octafluoropropane
Author Mühle, J.; Ganesan, A.L.; Miller, B.R.; Salameh, P.K.; Harth, C.M.; Greally, B.R.; Rigby, M.; Porter, L.W.; Steele, L.P.; Trudinger, C.M.; Krummel, P.B.; O'Doherty, S.; Fraser, P.J.; Simmonds, P.G.; Prinn, R.G.; Weiss, R.F.
Author Affil Mühle, J., Scripps Institution of Oceanography, La Jolla, CA. Other: Massachusetts Institute of Technology; University of Bristol, United Kingdom; CSIRO Marine and Atmospheric Research, Australia
Source Atmospheric Chemistry and Physics, 10(11), p.5145-5164. Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2010
Notes In English. Includes supplement: http://www.atmos-chem- phys.net/10/5145/2010/acp-10-5145-2010- supplement. pdf; published in Atmospheric Chemistry and Physics Discussions: 9 March 2010, http://www.atmos-chem-phys- discuss.net/10/6485/2010/acpd-10-6485- 2010.html ; accessed in May, 2011. 78 refs. GeoRef Acc. No: 310042. CRREL Acc. No: 65006810
Index Terms accuracy; aluminum; climatic change; firn; gases; human activity; ice; metals; pollution; stratosphere; microelement content; Antarctica; Greenland; air pollution; Arctic region; atmospheric transport; carbon dioxide; climate change; greenhouse gases; halogenated hydrocarbons; hexafluoroethane; octafluoropropane; organic compounds; perfluorocarbons; pollutants; tetrafluoromethane; trace elements; transport; troposphere; two-dimensional models
Abstract We present atmospheric baseline growth rates from the 1970s to the present for the long-lived, strongly infrared-absorbing perfluorocarbons (PFCs) tetrafluoromethane (CF4), hexafluoroethane (C2F6), and octafluoropropane (C3F8) in both hemispheres, measured with improved accuracies (~1-2%) and precisions (‹0.3%, or ‹0.2 ppt (parts per trillion dry air mole fraction), for CF4; ‹1.5%, or ‹0.06 ppt, for C2F6; ‹4.5%, or ‹0.02 ppt, for C3F8 within the Advanced Global Atmospheric Gases Experiment (AGAGE). Pre-industrial background values of 34.7±0.2 ppt CF4 and 0.1±0.02 ppt C2F6 were measured in air extracted from Greenland ice and Antarctic firn. Anthropogenic sources are thought to be primary aluminum production (CF4, C2F6, C3F8), semiconductor production (C2F6, CF4, C3F8) and refrigeration use (C3F8). Global emissions calculated with the AGAGE 2-D 12-box model are significantly higher than most previous emission estimates. The sum of CF4 and C2F6 emissions estimated from aluminum production and non-metal production are lower than observed global top- down emissions, with gaps of ~6 Gg/yr CF4 in recent years. The significant discrepancies between previous CF4, C2F6, and C3F8 emission estimates and observed global top-down emissions estimated from AGAGE measurements emphasize the need for more accurate, transparent, and complete emission reporting, and for verification with atmospheric measurements to assess the emission sources of these long-lived and potent greenhouse gases, which alter the radiative budget of the atmosphere, essentially permanently, once emitted.
URL http://www.atmos-chem-phys.net/10/5145/2010/acp-10-5145-2010.pdf
Publication Type journal article
Record ID 91470