Divergent predictions of carbon storage between two global land models: Attribution of the causes through traceability analysis
- Univ. of Oklahoma, Norman, OK (United States); Pacific Northwest National Lab., College Park, MD (United States)
- Univ. of Oklahoma, Norman, OK (United States); East China Normal Univ., Shanghai (China)
- Univ. of Oklahoma, Norman, OK (United States); Pacific Forestry Centre, Victoria, BC (Canada)
- Pacific Northwest National Lab., College Park, MD (United States)
- CSIRO Ocean and Atmosphere Flagship, Aspendale, VIC (Australia)
- Univ. of Oklahoma, Norman, OK (United States)
Representations of the terrestrial carbon cycle in land models are becoming increasingly complex. It is crucial to develop approaches for critical assessment of the complex model properties in order to understand key factors contributing to models' performance. In this study, we applied a traceability analysis which decomposes carbon cycle models into traceable components, for two global land models (CABLE and CLM-CASA') to diagnose the causes of their differences in simulating ecosystem carbon storage capacity. Driven with similar forcing data, CLM-CASA' predicted ~ 31 % larger carbon storage capacity than CABLE. Since ecosystem carbon storage capacity is a product of net primary productivity (NPP) and ecosystem residence time (τE), the predicted difference in the storage capacity between the two models results from differences in either NPP or τE or both. Our analysis showed that CLM-CASA' simulated 37 % higher NPP than CABLE. On the other hand, τE, which was a function of the baseline carbon residence time (τ'E) and environmental effect on carbon residence time, was on average 11 years longer in CABLE than CLM-CASA'. This difference in τE was mainly caused by longer τ'E of woody biomass (23 vs. 14 years in CLM-CASA'), and higher proportion of NPP allocated to woody biomass (23 vs. 16 %). Differences in environmental effects on carbon residence times had smaller influences on differences in ecosystem carbon storage capacities compared to differences in NPP and τ'E. Finally and overall, the traceability analysis showed that the major causes of different carbon storage estimations were found to be parameters setting related to carbon input and baseline carbon residence times between two models.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pacific Northwest National Laboratory (PNNL), College Park, MD (United States); Univ. of Oklahoma, Norman, OK (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); USDOE Laboratory Directed Research and Development (LDRD) Program; National Science Foundation (NSF)
- Contributing Organization:
- East China Normal Univ. (ECNU), Shanghai (China); Pacific Forestry Centre, Victoria, BC (Canada); Commonwealth Scientific and Industrial Research Organization (CSIRO), Aspendale, VIC (Australia)
- Grant/Contract Number:
- AC05-76RL01830; SC0008270; DEB 0743778; DEB 0840964; EPS 0919466; EF 1137293
- OSTI ID:
- 1256395
- Alternate ID(s):
- OSTI ID: 1330583
- Report Number(s):
- PNNL-SA-115823
- Journal Information:
- Earth System Dynamics (Online), Vol. 7, Issue 3; ISSN 2190-4987
- Publisher:
- European Geosciences UnionCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Carbon–nitrogen coupling under three schemes of model representation: a traceability analysis
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journal | January 2018 |
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