Mean Fluxes : By convention, a positive sign is used for sources of CO2 to the atmosphere and a negative sign for sinks of CO2 from the atmosphere. These fluxes can be directly compared with the results of large-scale independent bottom-up models, inventories of accounting systems.
Total flux : defined here as the sum of ocean fluxes, land ecosystem exchange and fossil fuel emissions. The Total flux is a direct result of inversions.
Natural fluxes : the difference between the total flux and the fossil emissions.
Ocean fluxes : results from all physical and biological processes responsible for the exchange of CO2 across the air-sea interface.
Land fluxes : defined as the sum of photosynthesis, ecosystem respiration and biomass burning.