Elsevier, Physics and Chemistry of the Earth, Parts A/B/C, 5-6(21), p. 471-476
DOI: 10.1016/s0079-1946(97)81144-5
Full text: Unavailable
The development of models to simulate the redistribution of anthropogenic carbon and the climate response to greenhouse gas forcing requires a substantial effort. The behavior of such models can be characterized by pulse response functions which allows one to build simple substitute models. We have used mixed-layer pulse response functions to describe the surface-to-deep mixing of tracers in the ocean and biospheric decay response functions to describe carbon turnover in the land biota. We build a simple carbon cycle-climate model using response functions. For the Princeton-GFDL ocean model, we find that the agreement between the complete model and its pulse substitute model is better than 4% for the cumulative uptake of anthropogenic carbon applying the IPCC stabilization scenarios S450 and S750. We have simulated the transient temperature response to an increasing CO2 concentration (1% yr−1) prescribing climate sensitivities of 2.1 and 4.6 K for a CO2 doubling in the substitute model. We find a global surface temperature warming of 1.6 and 2.4 K after 80 years in good agreement with the corresponding results (1.5 to 2.7 K) of 9 atmosphere-ocean general circulation models (Houghton et al., 1996). The pulse model is efficient; a 1000 year simulation of the pulse substitute model requires 25 seconds of CPU time on a workstation.