We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Abundances, emissions, and loss processes of the long-lived and potent greenhouse gas octafluorooxolane (octafluorotetrahydrofuran, c-C<sub>4</sub>F<sub>8</sub>O) in the atmosphere.
- Authors
Vollmer, Martin K.; Bernard, François; Mitrevski, Blagoj; Steele, L. Paul; Trudinger, Cathy M.; Reimann, Stefan; Langenfelds, Ray L.; Krummel, Paul B.; Fraser, Paul J.; Etheridge, David M.; Curran, Marc A. J.; Burkholder, James B.
- Abstract
The first observations of octafluorooxolane (octafluorotetrahydrofuran, c-C4F8O), a persistent greenhouse gas, in the atmosphere are reported. In addition, a complimentary laboratory study of its most likely atmospheric loss processes and infrared absorption spectrum and global warming potential (GWP) are reported. First atmospheric measurements of c-C4F8O are provided from the Cape Grim Air Archive (41° S, Tasmania, Australia, 1978-present), supplemented by two firn air samples from Antarctica, in situ measurements of ambient air at Aspendale, Victoria (38° S), and a few archived air samples from the Northern Hemisphere. Atmospheric abundances in the Southern Hemisphere have reached 74 ppq (parts per quadrillion, femtomol mol-1 in dry air) by 2017. However its growth rate has decreased from a maximum in 2004 of 4.3 ppq yr-1 to < 0.15 ppq yr-1 in 2017. Using a 12-box atmospheric transport model, globally averaged yearly emissions and abundances of c-C4F8O are calculated for 1951-2017. Emissions, which we speculate to derive predominantly from usage of c-C4F8O as a solvent in the semiconductor industry, peaked at 0.16 (±0.04, 2σ) kt yr-1 in 2004 and have after declined to < 0.01 kt yr-1 in 2017. Cumulative emissions over the full range of our record amount to 2.8 (2.6-3.2) kt, which correspond to 34 Mt of CO2-equivalent emissions. Infrared and ultraviolet absorption spectra for c-C4F8O as well as the reactive channel rate coefficient for the O(¹D) + c-C4F8O reaction was determined from laboratory studies. On the basis of these experiments, a radiative efficiency of 0.430 W m-2 ppb-1 (parts per billion, nanomol mol-1) was determined, which is one of the largest found for synthetic greenhouse gases. The global annually averaged atmospheric lifetime, including mesospheric loss, is estimated to be > 3000 years. GWPs of 8975, 12000, and 16000 are estimated for the 20, 100, and 500-year time-horizons, respectively.
- Subjects
GREENHOUSE gases; INFRARED absorption; ABSORPTION spectra; GLOBAL warming; ATMOSPHERIC models
- Publication
Atmospheric Chemistry & Physics Discussions, 2018, p1
- ISSN
1680-7367
- Publication type
Article
- DOI
10.5194/acp-2018-852