The NOAA/GMCC continuous CO2 record at the South Pole, 1975–1982

Hourly carbon dioxide concentrations at the south pole were obtained by nondispersive infrared analyzers for the years 1975–1978 and 1980–1982. A spectral analysis of the ambient CO2 variability showed very little power for periods shorter than 5 days. Our data showed good agreement with other data sets for the range of the annual fluctuation from 1977 to 1982 and disagreements for 1976. The estimated annual CO2 increase (about 0.6 to 2 ppm yr−1) and ranges of seasonal fluctuation were insensitive to the data selection methods used. After 1979, seasonal fluctuations apparently decreased.