Global Coupled Climate and Carbon Cycle Modeling

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Global Coupled Climate andCarbon Cycle Modeling

• Forrest M. Hoffman
• Computational Earth Sciences Group
• Computer Science and Mathematics Division
• Research partially sponsored by the 1) Climate
  Change Research Division (CCRD) of the Office of
  Biological and Environmental Research (OBER), and
  2) Mathematical, Information, and Computational
  Sciences (MICS) Division of the Office of
  Advanced Scientific Computing Research (OASCR)
  within the U.S. Department of Energy's Office of
  Science (SC). This research used resources of the
  National Center for Computational Science (NCCS)
  at Oak Ridge National Laboratory (ORNL) which is
  managed by UT-Battelle, LLC, for the U.S.
  Department of Energy under Contract No.
  DE-AC05-00OR22725. The National Center for
  Atmospheric Research (NCAR) is operated by the
  University Corporation for Atmospheric Research
  (UCAR) and receives research funding primarily
  from the National Science Foundation (NSF).

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CASA' Implemented and Run in CLM3

• Carnegie/Ames/Stanford Approach (CASA)
  biogeochemical model modified for use in global
  climate simulations and used in CSIM1.4
  (Randerson et al. 1997, Fung et al. 2005) was
  implemented, vectorized, tested, spun up, and run
  in the Community Land Model Version 3 (CLM3).
• CASA' simulates carbon assimilation via
  photosynthesis, mortality of plant functional
  types, decomposition of organic matter, and
  microbial respiration using three live carbon
  pools and nine dead carbon pools.

Net PrimaryProduction January6.4
Pg/month July8.6 Pg/month
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C4MIP Experiments with CASA'

• Coupled Climate/Carbon Cycle Model
  Intercomparison Project (C4MIP) Phase 1 --
  controlled experiment using prescribed sea
  surface temperatures (SSTs), sea ice cover, land
  cover change, ocean carbon fluxes, and fossil
  fuel emissions with active atmosphere and land
  surface models exchanging carbon over the 20th
  century (1900-2000).

• NCAR and SciDAC-1 Project implemented many
  changes to the CCSM3 release model to support
  biogeochemistry experiments BGC branch became
  the development version of CCSM3.1.

• CLM3-CASA' spun up with CAM for gt500 years, and
  most transient simulations were completed on Cray
  X1E at ORNL.

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CAM3-CASA' C4MIP NEE Plumes
click on image to play movie
Visualization by Jamison Daniel, National Center
for Computational Sciences at ORNL
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CCSM Carbon-LAnd Model Intercomparison Project
(C-LAMP)

• CCSM Biogeochemistry Working Group project to
  compare model capabilities and effects in the
  coupled climate system and to understand
  processes important for inclusion in the U.S.
  coupled model for IPCC Fifth Assessment Report
  (AR5).
• Current models running within the CCSM framework
  are
• CLM3-CASA' - Carnegie/Ames/Stanford Approach
  Model previously run in CSM1.4 (Fung)
• CLM3-CN - coupled carbon and nitrogen cycles
  based on the Biome-BGC model (Thornton)
• LSX-IBIS - Integrated Biosphere Simulator from U.
  Wisconsin previously run in PCTM (Thompson)
• Models are running on the Computational Climate
  Science End Station (Warren Washington, PI) on
  the Cray X1E in the National Center for
  Computational Sciences (NCCS) at ORNL.
• Program for Climate Model Diagnosis and
  Intercomparison (PCMDI) will distribute model
  results via Earth System Grid.

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CCSM C-LAMP Protocol

• Experiment 1 Models will be forced with an
  improved NCEP/NCAR reanalysis climate data set
  (Qian, in press) to examine the influence of
  climate variability, prescribed atmospheric CO2,
  and land cover change on terrestrial carbon
  fluxes during the 20th century (specifically
  1948-2004).
• Experiment 2 Models will be forced with an
  active atmosphere (CAM3), prescribed atmospheric
  CO2, prescribed sea surface temperatures and
  ocean carbon fluxes to examine the effect of a
  coupled biosphere-atmosphere for carbon fluxes
  and climate during the 20th century.
• CCSM3.1 partially coupled ("I" and "F"
  configurations) run at T42 resolution (2.8
  2.8), spectral Eulerian dycore, 10.27-0.53
  ocean and sea ice data models.
• Complete experimental protocol, output fields,
  metrics for model evaluation, and other
  information is available at http//climate.ornl.go
  v/bgcmip/.

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C-LAMP Fluxnet Tower/Point Offline Simulations

• Offline simulations at Fluxnet Tower sites were
  added to the C-LAMP experiments
• to verify and validate biogeochemistry modules
  against high frequency (and high quality)
  observations
• to identify any issues with output fields,
  post-processing code, and intercomparison
  strategy and
• to serve as a quick "dry run" for the global
  simulations.
• Reto Stöckli (Colorado State U./ETH Zürich),
  Steve Running and Faith Ann Heinsch (U. Montana),
  Kathy Hibbard (NCAR) are providing ready-to-run
  meteorological data and carbon flux measurements.
• CarboEurope site data were used first AmeriFlux
  sites are now being added.
• So far, offline simulations using CLM3-CASA' and
  CLM3-CN have been run following the same
  protocol as Experiment 1.

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Fluxnet Tower Sites Used for Offline Model
Intercomparison
CarboEurope and AmeriFlux site meteorology are
being used to spin up and force model
experiments. Sites were chosen to maximize the
coverage of land cover types in the models.
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Vielsalm Tower/Point Offline Model Diagnostics
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Contact
Forrest Hoffman Oak Ridge National
Laboratory [phone] forrest_at_climate.ornl.gov

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