%0 Journal Article
%A Maiss, Manfred
%A Levin, Ingeborg
%D 1994
%F heidok:6867
%J Geophysical Research Letters 
%K sulfur hexafluoride , atmosphere , greenhouse gas
%R 10.11588/heidok.00006867
%T Global increase of SF6 observed in the atmosphere
%U https://archiv.ub.uni-heidelberg.de/volltextserver/6867/
%X High precision long-term observations of the trace gas sulphur hexafluoride (SF6) in background air at Neumayer station, Antarctica (1986-1991), and at Izana observatory, Tenerife (1991-1992), are presented. Since the very first measurements in 1970 (0.03pptv), the purely anthropogenic greenhouse gas SF6 has increased by two orders of magnitude to a global mean value of 2.8pptv in 1992. The observations can best be fitted by a quadratic curve with a recent increase rate of 8.3%/yr. A significant north-south gradient of 0.29pptv is observed. From this gradient an interhemispheric exchange time of 1.4 years is derived. A modeled atmospheric budget history agrees reasonably well with estimates of global SF6 production rates and leads to an extrapolated SF6 concentration of about 20pptv for the year 2030.