O2/N2 ratios and CO2 mole fractions of air samples collected at Cape Ochiishi

The present data set is time series data of atmospheric O2/N2 ratios and CO2 mole fractions from air samples collected at Cape Ochiishi situated at the base of Nemuro Peninsula in eastern Hokkaido, Japan. There is a monitoring station on the top of a cliff 42.4 m above the sea level at the southern tip of the cape facing the Pacific Ocean. Air samples, drawn by a pump from an intake placed on a tower at a height of 51.5 m above ground level, are forced into Pyrex glass flasks. The collected air samples are sent back to a laboratory in NIES, where O2/N2 ratios and CO2 mole fractions are measured.