Variations of atmospheric carbon dioxide concentration at Syowa Station (69°00’ S, 39°35’ E), Antarctica

Abstract

Precise measurements of the atmospheric CO2 concentration were initiated at Syowa Station, Antarctica in 1983. Preliminary inspection of the data obtained up to the present showed that: (1) a regular diurnal variation is not observable; (2) irregular variations are sometimes observed with extremely small amplitudes of 0.2 ppmv at most; (3) a seasonal variation with the minimum concentration in mid-April and the maximum concentration in mid-October; and peak-to-peak amplitudes of about 1.2 ppmv are detected; (4) annual mean values of the CO2 concentration are 341.2 and 342.6 ppmv for 1983 and 1984, respectively.