The sampling site at Cape Grim, Tasmania, is operated in cooperation with Graeme Pearman and Paul Fraser of the Commonwealth Scientific and Industrial Research Organisation's (CSIRO's) Division of Atmospheric Research. Cape Grim replaced Kaitorete Spit, New Zealand, in the NOAA/CMDL network after it was established that Cape Grim was a more suitable site for representative measurements at that latitude (Conway et al. 1988). From the outset of this cooperative program, samples have been taken in 0.5-L flasks. However, two sampling procedures have been used. One of the procedures is followed at all of the NOAA/CMDL flask sampling sites, as detailed in Komhyr et al. (1985a) and Conway et al. (1988). In the second procedure, the air samples are dried by passage through a glass column packed with anhydrous, granular magnesium perchlorate, as detailed in CSIRO (1989). From 1985 to 1992, annual average mixing ratios of CO2 at Cape Grim, calculated on the basis of undried air samples, rose from 343.5 parts per million (ppm) to 353.5 ppm. This represents an annual increase of 1.43 ppm at Cape Grim in comparison with the increase of 1.43 ppm per year reported by Conway et al. (1994) for all NOAA/CMDL flask sampling sites from 1981-92.
Date revised 4/10/95 (gg)
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