Carbon dioxide concentration in the upper troposphere and lower stratosphere. III

Investigations of the atmospheric CO₂ content have shown that marked differences between samples collected in the troposphere and stratosphere exist (Bischof, 1965; Bischof & Bolin, 1966; Bischof, 1971). Using all data available from flights during 1963–68, a significant change in amplitude and phase of the annual cycle was found when comparing the variations at 12 km with those at lower levels (Bolin & Bischof, 1970). A separation between tropospheric and stratospheric samples was, however, not undertaken, because the data was not adequate. If including samples from the years 1969–71, a data separation clearly shows the change in amplitude and phase between upper troposphere and lower stratosphere. The results are presented below and compared with data obtained at Scripps Institution of Oceanography. The data also show that the annual increase of CO₂ in the atmosphere is increasing by about 0.09 ppm/year².