A43E-0338
Evaluation of new stratospheric age tracers and SF6
Thursday, 17 December 2015
Poster Hall (Moscone South)
Johannes C. Laube1, Eileen Gallacher2, David Oram3, Harald Boenisch4, Andreas Engel4, Paul J. Fraser5, Thomas Röckmann6 and William T Sturges1, (1)University of East Anglia, Norwich, NR4, United Kingdom, (2)University of East Anglia, Norwich, United Kingdom, (3)National Centre for Atmospheric Science, Leeds, United Kingdom, (4)Goethe University Frankfurt, Institute for ATmospheric and Environmental Science, Frankfurt, Germany, (5)Commonwealth Scientific and Industrial Research Organisation, Centre for Australian Weather and Climate Research, Aspendale, Australia, (6)Utrecht University, Utrecht, Netherlands
Abstract:
Sulphur hexafluoride (SF6) is a very long-lived, potent greenhouse gas. Its abundances continue to increase in the atmosphere. Due to its inert behaviour it has also been extensively used as a tracer of transport in the ocean, the troposphere and the stratosphere. We here combine long-term tropospheric records obtained from the Cape Grim Baseline station, Tasmania, with stratospheric data from high-altitude aircraft and balloon campaigns. We then assess the novel use of several alternative transport tracers (e.g. C2F6, C3F8 and HFC-23) in the stratosphere. The results indicate good suitability for some of these gases in terms of their inertness, tropospheric growth rates and measurement precisions. In addition we and compare the derived mean ages to those obtained from SF6 and find indications for the possibility of the existence of a stratospheric SF6 sink. The latter finding would also imply that the total atmospheric lifetime of SF6 is substantially shorter than previously believed, with further implications for its use as a transport tracer in the stratosphere.
