The Carbon-Land Model Intercomparison Project: A Protocol and Metrics for Global Biosphere Models

Forrest M Hoffman, Oak Ridge National Laboratory, forrest@climatemodeling.org (Presenting)
James T Randerson, University of California, Irvine, jranders@uci.edu
Inez Fung, University of California, Berkeley, ifung@berkeley.edu
Peter Thornton, National Center for Atmospheric Research, thornton@ucar.edu
Jeff Lee, National Center for Atmospheric Research, jeff@ucar.edu
Gordon Bonan, National Center for Atmospheric Research, bonan@ucar.edu
Steve Running, University of Montana, swr@ntsg.umt.edu
David J Erickson, Oak Ridge National Laboratory, ericksondj@ornl.gov
John Drake, Oak Ridge National Laboratory, drakejb@ornl.gov

The Carbon-Land Model Intercomparison Project (C-LAMP) began as a project to intercompare terrestrial biogeochemistry models in the Community Climate System Model (CCSM) framework. A collaboration between the CCSM Biogeochemsitry Working Group the U.S. Dept. of Energy Scientific Discovery through Advanced Computing (SciDAC) initiative, C-LAMP has evolved into an international protocol and set of metrics for grading the scientific performance of models by comparison with best-available observational datasets, from satellite to leaf-scale measurements. In the first set of experiments, the models are forced with an improved NCEP/NCAR reanalysis climate data set to examine the ability of the models to reproduce surface carbon and energy fluxes at multiple sites and to examine the influence of climate variability, prescribed atmospheric CO₂ and nitrogen deposition on terrestrial carbon fluxes during the 20th century. An active atmosphere model is used in the second set of experiments with prescribed atmospheric CO₂ concentrations. The objective of these simulations is to examine the effect of a coupled biosphere-atmosphere for carbon fluxes and climate during the 20th century. Presented will be preliminary results from offline and partially coupled experiments using two models, CLM3-CASA' and CLM3-CN, in the CCSM framework. Metadata standards developed to support archival and distribution of model output via the Earth System Grid (ESG) will also be presented.