A globally aggregated reconstruction of cycles of carbon and its isotopes

A globally aggregated model of the carbon cycle with an upwelling/diffusion ocean and a 6-box biosphere is developed to consistently reconstruct the carbon cycle and isotopic variation in the atmosphere and oceans. The calculated atmospheric delta(13)C trend, based on a model that reproduces the CO2 concentration record, agrees well with the observed ice core and tree-ring delta(13)C records. The model has also been used to estimate the delta(13)C of oceanic dissolved inorganic carbon, and our model results match observations well within the range of observational uncertainty. This model is found to also match measured values (within measurement error) of the pre-bomb decrease in C-14 in the atmosphere and the mixed layer due to the Suess Effect the bomb-C-14 in the mixed layer, the bomb-C-14 penetration depth, the bomb-C-14 ocean inventory, and the vertical distribution of total dissolved carbon and C-14. In addition, the model is used to close the balance between the rates of increase of global inventory and of bomb production of radiocarbon. Our confidence in both the global aggregation of data and our understanding of global carbon cycle is strengthened by the consistency between carbon isotope concentration data and model results.