Simulations of the global carbon cycle and anthropogenic CO{sub 2} transient. Final report

• Main Authors: Joos, F., Stocker, T.
• Other Authors: United States. Department of Energy. Office of Energy Research.
• Format: Report
• Language: English
• Published: Bern Univ. (Switzerland). Inst. fuer Physik 1996
• Subjects: Box Models; Carbon 13; Diffusion; Greenhouse Effect; Carbon Sinks; Carbon Dioxide; Historical Aspects; Pollution Sources; Biosphere; Carbon 14; Carbon Cycle; Air-Water Interactions; 54 Environmental Sciences; H Codes; Seas; Fallout; Global Aspects; G Codes; ice core; North Atlantic
• Online Access: https://doi.org/10.2172/484588; https://digital.library.unt.edu/ark:/67531/metadc687870/

The major emphasis of our DOE funded research was to study the redistribution of anthropogenic carbon in the climate system and to constrain the global budgets of anthropogenic carbon and the carbon isotopes {sup 13}C and {sup 14}C for the historical period. We have continued the development of box models of the ocean carbon cycle (HILDA model) and the land biota. The coupled model (Bern model) was chosen as the reference model for scenario calculations and the calculations of global warming potential by the Intergovernmental Panel on Climate Change. These models were applied (1) to estimate the uptake of anthropogenic carbon by the ocean and the land biosphere for the last 200 years; (2) to investigate uncertainties in deconvolved fertilization fluxes into the land biota due to uncertainties in ice core CO{sub 2} data; (3) to study the relationship between future atmospheric CO{sub 2} levels and carbon emissions; (4) to investigate the budgets of bomb-produced radiocarbon and fossil {sup 13}C. We assessed the utility of bomb-produced and natural {sup 13}C observations to validate ocean models of anthropogenic CO{sub 2} uptake and tested the eddy diffusion parameterization of large-scale vertical transport in ocean box models. For this, vertical tracer transport in box-diffusion models and the 3-D ocean general circulation model from GFDL/Princeton was compared. We analyzed the distribution of the conservative property {Delta}C* to obtain a direct estimate based on marine measurements of the uptake of anthropogenic CO{sub 2} by the North Atlantic. We contribute to the missing sink debate by using atmospheric CO{sub 2} and {sup 13}C levels to disentangle the net carbon fluxes into the land biota and the ocean. A simplified representation for 4 different ocean models of anthropogenic CO{sub 2} uptake based on mixed-layer pulse response functions was developed.