Variations in concentration of carbon dioxide in the free atmosphere

Abstract

Variations of carbon dioxide in the atmosphere have been investigated by the analysis of 188 flask aamples taken from an airplane at heights up to 3 km during the period 1967 to 1961. The carbon dioxide concentration changes considerably from one time to another. Above lo00 rn the range is 308 to 320 ppm, the average 314 ppm. The range and average both increaae towards the ground. A seasonal variation in concentration is noted. The amplitude of the variation decreaees with increasing height above the ground. The minimum occura in summer and the maximum in the winter at all altitudes. Some of the seasonal variations at ground level as previously obtained from the Scandinavian network for carbon dioxide sampling do not show up in the analyses from upper levels.