Continuous Observational Data of Atmospheric CO2 Mixing Ratios at Cape Ochi-ishi

The present data set is a set of continuous observational data of background CO2 mixing ratios in the vicinity of 40°N in the northern region of East Asia, measured at Cape Ochi-ishi situated on Nemuro Peninsula, Hokkaido, Japan. Because Cape Ochi-ishi, stretching into the Pacific Ocean, has a low population density and because the cape itself is a protected area with limited access, it is subjected to very small influence from local anthropogenic CO2 emissions. In summer, Cape Ochi-ishi is under the influence of air masses transported from the direction of the Pacific Ocean and Japan, and in winter it is influenced by the air masses transported from the direction of Siberia and the North Pole.