Atmospheric Fluoroform (CHF₃, HFC-23) at Cape Grim, Tasmania - D. E. Oram et al.

Methane, Nonmethane Hydrocarbons, Alkyl Nitrates, and Chlorinated Carbon Compounds in Whole-air Samples - D. Blake

Trifluoromethyl Sulfur Pentafluoride (SF₅CF₃) and Sulfur Hexafluoride (SF₆) from Dome Concordia - W. T. Sturges et al.

In addition to carbon dioxide (CO₂), several other atmospheric trace gases are radiatively active, and thereby can contribute to a greenhouse warming of the lower atmosphere. Some of these other greenhouse gases include methane (CH₄), nitrous oxide (N₂), ozone (O₃), and certain halogenated compounds. The combined radiative forcing from these other trace gases is approximately equal to that of CO₂ (Prather et al. 1996). Some of the halogenated compounds, while present in the atmosphere at very low concentrations, are of considerable interest because of their high global warming potentials (GWPs), long atmospheric residence times, and current growth rates.

Oram et al. (1998) quantified the increasing atmospheric concentration of one halocarbon, fluoroform (CHF₃ or HFC-23), from samples taken at Cape Grim, Tasmania. This persistent gas, a by-product of the manufacture of HCFC-22 (CHClF₂), has an atmospheric lifetime of 200-300 years and a GWP of about 10,000 times that of CO₂ on a unit-mass basis. The dataset included here provides the Oram et al. Cape Grim fluoroform data.

Sturges et al. (2000) identified trifluoromethyl sulfur pentafluoride (SF₅CF₃) as a previously unreported gas that is long-lived (an atmospheric residence of several hundred to several thousand years) and with significant GWP (perhaps 18,000 times that of CO₂ on a unit-mass basis). The database included here quantifies atmospheric concentrations of SF₅CF₃ and sulfur hexafluoride (SF₆), another greenhouse gas, from 1965 through 1999, based on samples obtained from firn (deep consolidated snow) at Dome Concordia (eastern Antarctica).

References

Oram, D.E., W.T. Sturges, S.A. Penkett, A. McCulloch, and P.J. Fraser. 1998

Growth of fluoroform (CHF₃, HFC-23) in the background atmosphere. Geophysical Research Letters 25:35-38.

Prather, M., R. Derwent, D. Ehhalt, P. Fraser, E. Sanhueza, and X. Zhou. 1996.

Radiative forcing of climate change: Other trace gases and atmospheric chemistry. pp. 86-103 In J.T. Houghton, L.G. Meira Filho, B.A. Callender, N. Harris, A. Kattenberg, and K. Maskell (eds.). Climate Change 1995: The Science of Climate Change. Cambridge University Press, Cambridge, U.K.

Sturges, W.T., T.J. Wallington, M.D. Hurley, K.P. Shine, K. Sihra, A. Engel, D.E. Oram, S.A. Penkett, R. Mulvaney, and C.A.M. Brenninkmeijer 2000.

A potent greenhouse gas identified in the atmosphere: SF₅CF₃. Science 289:611-613.

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