Atmospheric Oxygen in 1967 to 1970

Science  26 Jun 1970:
Vol. 168, Issue 3939, pp. 1582-1584
DOI: 10.1126/science.168.3939.1582


Observations of atmospheric oxygen in clean air between 50°N and 60°S, mainly over the oceans, yield an almost constant value of 20.946 percent by volume in dry air. Since 1910 changes with time over the globe appear to be either zero or smaller than the uncertainty in the measurements.