Dynamics of a Closed Low-Parameter Compartment Model of the Global Carbon Cycle

A closed dynamic compartment model of the global carbon cycle and its modifications with a small number of external parameters, which are constructed on the basis of data on the current and preindustrial carbon fluxes and reserves in reservoirs, are studied. The first possible controlling parameter is the amount of anthropogenic CO2 emission into the atmosphere. Closure in substance allows a decrease in the dimensionality of dynamic models and yields another variable parameter-the system's total mass, whose change reflects the level of uncertainty in the knowledge of the amount of reserves. The calibration of unsaturated fluxes in each of the models is based on an algorithm developed earlier for local ecosystems, and the measured differences between the fluxes opposite in sign for several times are used to calculate the coefficients of saturated fluxes. The model's modifications make it possible to estimate the degree to which the oceanic active layer may be involved in rapid exchange with the atmosphere and to introduce the factor of land use as an additional anthropogenic effect. The time trajectories of carbon reserves in reservoirs are calculated until 2100 under variations in anthropogenic emissions in accordance with the IPCC basic scenarios until 2100 for the basic model and its modifications.