This paper presents a 2-year record (from September 1996 to July 1998) of a
tmospheric (CO)-C-14 measurements on whole air samples taken at the Mt. Son
nblick observatory (3106 m), a remote high-altitude site in Central Europe.
An overall measurement precision of ca. 1/4 molecule (CO)-C-14 per cm(3) a
ir has been achieved. A few events including unexpectedly low CO and (CO)-C
-14 values in winter 1996/97 will be discussed in some detail incorporating
stable isotope information. Since the amount of (CO)-C-14 data available f
or the Northern Hemisphere (NW) is rather sparse, this most detailed long-t
erm (CO)-C-14 record for NH temperate latitudes may be a valuable contribut
ion to the assessment of global atmospheric OH concentrations. (C) 2000 Els
evier Science B.V. All rights reserved.