Metzler, Holger
- Max Planck Society
Radiocarbon (C-14) is a powerful tracer of the global carbon cycle that is commonly used to assess carbon cycling rates in various Earth system reservoirs and as a benchmark to assess model performance. Therefore, it has been recommended that Earth System Models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 report predicted radiocarbon values for relevant carbon pools. However, a detailed representation of radiocarbon dynamics may be an impractical burden on model developers. Here, we present an alternative approach to compute radiocarbon values from the numerical output of an ESM that does not explicitly represent these dynamics. The approach requires computed C-12 stocks and fluxes among all carbon pools for a particular simulation of the model. From this output, a time-dependent linear compartmental system is computed with its respective state-transition matrix. Using transient atmospheric C-14 values as inputs, the state-transition matrix is then applied to compute radiocarbon values for each pool, the average value for the entire system, and component fluxes. We demonstrate the approach with ELMv1-ECA, the land component of an ESM model that explicitly represents C-12, and C-14 in 7 soil pools and 10 vertical layers. Results from our proposed method are highly accurate (relative error
carbon cycle models; compartmental systems; radiocarbon; model diagnostics; dynamical systems; Earth system models
Journal of Advances in Modeling Earth Systems (Electronics)
2020, volym: 12, nummer: 1, artikelnummer: e2019MS001776
Utgivare: AMER GEOPHYSICAL UNION
Meteorologi och atmosfärsvetenskap
https://res.slu.se/id/publ/109580