Continuous Observational Data of Atmospheric CO2 Mixing Ratios on Hateruma Island

The present data set is a set of continuous observational data of background CO2 mixing ratios in the vicinity of 20°N in the Western Pacific Ocean facing East Asia, measured on Hateruma Island, Okinawa Prefecture, Japan. Hateruma Island is a small island with a diameter of approx. 5 km. Because it is subjected to very small influence from local terrestrial ecosystem and/or anthropogenic CO2 emissions, the daily variations are small and the CO2 mixing ratios observed here can therefore be regarded as representative of the sub-tropics in the East Asian region. The Hateruma data reflects the influence from the Pacific Ocean in summer and from the Asian continent in winter, located downwind from each region, respectively.