Climate Change Working Group CCWG

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Climate Change Working Group (CCWG) July, 2004
Co-chairs Gerald A. Meehl, Ben Santer,
and Warren Washington
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Currently Active Global Coupled Climate Models

• PCM atmosphere CCM3.2, T42, 18L
• ocean POP, 2/3 to 1/2 degree in
  eq. Tropics, 32L,
• biharmonic diffusion,
  Pacanowski/Philander mixing
• sea ice dynamic (EVP),
  thermodynamic
• land surface LSM
• CCSM2 atmosphere CAM2, T42, 26L
• ocean POP, 1 to 1/2 degree in eq.
  Tropics, 40L, GM, KPP
• sea ice dynamic (EVP),
  thermodynamic
• land CLM
• CCSM3 atmosphere CAM3, T85, 26L
• ocean POP, 1 to 1/2 degree in eq.
  Tropics, 40L, GM, KPP
• sea ice dynamic (EVP),
  thermodynamic
• land CLM
• (T42 class models run 8 years per day on IBM SP
  Power4 T85 is about a factor of two slower)

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CCSM3 is current active model for new climate
change experiments for the CCWG CCSM2 used
mainly for CMIP thermohaline circulation
sensitivity experiments PCM being run only for
limited experiments to leverage information from
the large archive of completed 20th and 21st
century climate simulations
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PCM 20th, 21st and 22nd Century Simulations

• Volcano-only, 1870-2000, 4 members
• Ozone-only, 1870-2000, 4 members
• GHG-only, 1870-2000, 4 members
• Sulfate aerosol-only, 1870-2000, 4 members
• GHGozone, 1870-2000, 4 members
• Solarozone, 1870-2000, 4 members
• Solar-only, 1870-2000, 4 members
• GHGsulfatesozone, 1870-2000, 10 members
• GHGsulfatesozonesolar, 1870-2000, 4 members
• GHGsulfatesozonesolarvolcano, 1870-2000, 4
  members
• Solarvolcano, 1870-2000, 4 members
• Solarvolcanoozone, 1870-2000, 4 members
• GHGsulfates, 1870-2000, 4 members
• control simulation (1500 years)
• 1 CO2 increase to doubling (5 members), and
  quadrupling (1 member) 150 years at 2XCO2, 150
  years at 4XCO2 (CMIP)
• ACACIA Business as Usual, 5 members,
  2000-2100 1 member to 2200
• ACACIA stabilization, 5 members, 2000-2100, 1
  member to 2200
• SRES A2 ,B2, A1FI (single members), A1B and B1
  (four members), 2000-2100
• SRES A1B and B1 stabilized at 2100 values run to
  2200 (four members), one each to 2300

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The PCM set of simulations represents perhaps the
largest global coupled model dataset of
multi-member ensemble 20th and 21st century
climate simulations, performed with a single
model, currently in existence Over 190
simulations Over 21,000 years of simulation 100
Tb
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Another source for model output

• A large database of PCM and CCSM2 results have
  been postprocessed and quality controlled for
  easy distribution to the scientific community.
• Over 80 PCM runs
• Atmospheric monthly and daily data.
• Oceanic monthly data.
• CCSM2.0.1 control run (years 350-999)
• See http//www.nersc.gov/projects/gcm_data/ for
  details or email mfwehner_at_lbl.gov

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List of runs for IPCC AR4  1. 20th century
simulation to year 2000, then fix all
concentrations at year 2000 values and run to
2100 (CO2 360ppm)  2. 21st century simulation
with SRES A1B to 2100, then fix all
concentrations at year 2100 values to 2200 (CO2
720ppm)  3. 21st century simulation with SRES B1
to 2100, then fix all concentrations at year 2100
values to 2200 (CO2 550ppm)  4. 21st century
simulation with SRES A2 to 2100  5. 1 CO2 run to
year 80 where CO2 doubles at year 70 with
corresponding control run 6. 100 year (minimum)
control run including same time period as in 1
above 7. 2XCO2 equilibrium with
atmosphere-slab ocean 8. Extend one A1B and B1
simulation to 2300  9. 1 CO2 run to
quadrupling with an additional 150 years with
CO2 fixed at 4XCO2  10. 1 CO2 run to doubling
with an additional 150 years with CO2 fixed at
2XCO2
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CCSM3 T85 IPCC Simulations
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PCM 2XCO2 2.1C TCR 1.32
C CCSM3 2XCO2 2.7 C TCR 1.46 C
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Earth Simulator CCSM3
Simulations
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Global coupled climate model analyses for the
IPCC AR4  Modeling groups around the world have
agreed to perform an unprecedented set of
coordinated 20th and 21st Century climate change
experiments, in addition to commitment
experiments extending to the 22nd Century, for
the IPCC Fourth Assessment Report.  WGCM is
coordinating an international effort to collect,
archive and analyze output from this multi-model
dataset for direct input to the IPCC AR4 in
2004-2005.  The WGCM Climate Simulation Panel
has been set up to oversee this effort chair,
Gerald Meehl (NCAR, USA), John Mitchell (Hadley
Centre, U.K.), Bryant McAvaney (BMRC, Australia),
Curt Covey (PCMDI, USA), Mojib Latif (MPI,
Germany), and Ron Stouffer (GFDL, USA). This
panel is coordinating the collection and archival
of the multi-model output at PCMDI. The initial
deadline for submission of model data is
September 1, 2004.
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Individuals and groups can sign up before
September 1, 2004 to analyze aspects of the
simulations. An announcement has been made
inviting open participation (CLIVAR Exchanges,
EOS, BAMS, email). Contact IPCC_analysis_at_ucar.edu
if you are interested in participating. Results
will be presented at a Workshop on Analyses of
Climate Model Simulations for the IPCC AR4 March
1-4, 2005, convened by U.S. CLIVAR, and hosted by
the International Pacific Research Center,
University of Hawaii.  Scientific papers
describing the results presented at the workshop
must then be written by the respective
investigators, and submitted to peer-reviewed
journals by the time of the Second Lead Authors
Meeting in May, 2005, in order to be fully
included and assessed in the AR4 as specified by
the guidelines of IPCC.  
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a.      Scientific objectives of the CCWG
Main theme Quantifying uncertainty in climate
change projections  Requirements  1. Improve
regional climate simulation and extremes higher
resolution atmospheric component, T85, T170
coupled simulations more outputs from model in
time and space for extremes analyses  2.
Probabilistic projections of climate change
Ensemble simulations with various forcings and
scenarios  3. Understand model response to
changes of forcing climate sensitivity a main
issue  
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Planned CCSM3 simulations T170 AMIP
simulation T170 CCSM3 coupled simulation, 1950 -
2050 T85 Historical simulation from 1870 to 2000
(GHGs SA SAI SV V O) (130 years) with
sulfate aerosols (direct and indirect effect)
 T85 Historical simulation from 1870 to 2000
(GHGs SA SV V O CA) (130 years) with
carbon aerosols varying in space and time T85
 Historical simulation from 1870 to 2000 (GHGs
SA SV V O DA) (130 years) with dust
aerosols T85  Historical simulation 1870 to 2000
with sulfate indirect only  T85 Historical
simulation 1870 to 2000 with dust aerosols
only  T85 Historical simulation 1870 to 2000 with
carbon aerosols only