Toward "optimal" integration of terrestrial biosphere models

Christopher R Schwalm, Deborah N Huntzinger, Joshua B. Fisher, Anna M. Michalak, Kevin Bowman, Philippe Ciais, Robert Cook, Bassil El-Masri, Daniel Hayes, Maoyi Huang, Akihiko Ito, Atul Jain, Anthony W. King, Huimin Lei, Junjie Liu, Chaoqun Lu, Jiafu Mao, Shushi Peng, Benjamin Poulter, Daniel RicciutoKevin Schaefer, Xiaoying Shi, Bo Tao, Hanqin Tian, Weile Wang, Yaxing Wei, Jia Yang, Ning Zeng

Research output: Contribution to journalArticle

32 Scopus citations

Abstract

Multimodel ensembles (MME) are commonplace in Earth system modeling. Here we perform MME integration using a 10-member ensemble of terrestrial biosphere models (TBMs) from the Multiscale synthesis and Terrestrial Model Intercomparison Project (MsTMIP). We contrast optimal (skill based for present-day carbon cycling) versus naïve ("one model-one vote") integration. MsTMIP optimal and naïve mean land sink strength estimates (-1.16 versus -1.15 Pg C per annum respectively) are statistically indistinguishable. This holds also for grid cell values and extends to gross uptake, biomass, and net ecosystem productivity. TBM skill is similarly indistinguishable. The added complexity of skill-based integration does not materially change MME values. This suggests that carbon metabolism has predictability limits and/or that all models and references are misspecified. Resolving this issue requires addressing specific uncertainty types (initial conditions, structure, and references) and a change in model development paradigms currently dominant in the TBM community.

Original languageEnglish (US)
Pages (from-to)4418-4428
Number of pages11
JournalGeophysical Research Letters
Volume42
Issue number11
DOIs
StatePublished - Jun 16 2015

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Keywords

  • carbon cycle
  • model integration
  • modeling

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Geophysics

Cite this

Schwalm, C. R., Huntzinger, D. N., Fisher, J. B., Michalak, A. M., Bowman, K., Ciais, P., Cook, R., El-Masri, B., Hayes, D., Huang, M., Ito, A., Jain, A., King, A. W., Lei, H., Liu, J., Lu, C., Mao, J., Peng, S., Poulter, B., ... Zeng, N. (2015). Toward "optimal" integration of terrestrial biosphere models. Geophysical Research Letters, 42(11), 4418-4428. https://doi.org/10.1002/2015GL064002