The Distribution of Oxygen in Air: Implications for the Global Carbon Cycle

Princeton University, Princeton NJ

Investigators

Abstract

Data on the distribution of oxygen (O2) in air constrain rates of carbon dioxide (CO2) uptake by the global land biosphere and the ocean. They also allow us to calculate seasonal net production in the oceans on a hemispheric scale. The CO2 concentration of air is rising about half as fast as combustion adds CO2; the land biosphere and the oceans sequester the remainder. Since growth of the land biosphere produces O2, atmospheric O2/N2 data allow a partitioning of the sequestration between these two globally important sinks. This project supports continued measurements of the O2/N2 ratio of air collected at nine remote sampling sites from Barrow, Alaska, to Syowa, Antarctica, and on container ships transiting between Los Angeles and Australia. The results will improve and extend estimates of climatological values of CO2 sequestration rates and ocean carbon fluxes. A combination of empirical correlations and modeling studies will be used to examine the relationship between climate and the two important biospheric fluxes calculated from O2/N2 data: CO2 sequestration rates by the land biosphere and ocean carbon fluxes. The objective is to achieve process level insights into controls on these two fluxes by characterizing interannual variations and their causes.