The sampling site on Ascension Island is operated in cooperation with the U.S. Air Force and Pan American World Airways. The NOAA/CMDL flask data from Ascension Island show an increase in the annual value from 338.8 parts per million (ppm) in 1980 to 355.2 ppm in 1992, or 1.37 ppm per year. Conway et al. (1994) reported a 1.43-ppm per year mean annual growth rate during 1981?92 for all NOAA/CMDL flask sampling sites.
Atmospheric CO mixing ratios at Ascension Island show a seasonal pattern. Conway et al. (1994) found that the seasonality at Ascension Island does not appear to be affected by transport of northern air and reported the peak-to-trough seasonal amplitude for Ascension Island was 2.0 ppm for 1981?92.
Ascension Island Graph
Ascension Island Table
Access to Digital Data
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Date revised 4/10/95 (gg)
[an error occurred while processing this directive] Date revised 4/10/95 (gg)