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4th WOAP Meeting29 March 2010
K. E. Taylor
The Working Group on Coupled Modeling
Karl E. Taylor
Program for Climate Model Diagnosis and Intercomparison (PCMDI)
with credit and thanks to Sandrine Bony
Presented to the Fourth WCRP Observation and Assimilation Panel Meeting
Hamburg, Germany
29 March 2010
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
Who are the WGCM?
Members
Sandrine Bony (co-chair)
Gerald Meehl (co-chair)
Veronica Eyring
Marco Giorgetta
David Karoly
M. Kimoto
Corinne Le Quéré
Natalie Mahowald
Catherine Senior
Bin Wang
Ex-Officio Members
Gokhan Danabasoglu
Helge Drange
Greg Flato
Filippo Giorgi
John Mitchell
Ronald Stouffer
Karl Taylor
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
What is the WGCM’s mission?
• Foster the development of coupled climate models (and now ESMs)
• Coordinate model experiments and inter-comparisons to:
better understand natural climate variability
predict the climate response to natural & anthropogenic perturbations
Promote and facilitate model evaluation and diagnosis of shortcomings
A balance among:Predicting – Evaluating - Understanding
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
Major challenges
• How can we improve our confidence in climate models?
• How can we assess the credibility of model projections ?
4th WOAP Meeting29 March 2010
K. E. Taylor
LES modelsCloud Resolving Models
Single ColumnModels
3D-Climate ModelsNWP Models
High resolution global models(global CRM, MMF)
Global observational datasets
Field campaigns & instrumented sites
How can we gauge and gain confidence in GCMs projections?(1) Bottom-Up approach : evaluate and improve the physical basis of climate models
through large-scale and process-scale evaluations
Analysis & Understandingclimate change
Model projections
4th WOAP Meeting29 March 2010
K. E. Taylor
LES modelsCloud Resolving Models
Single ColumnModels
3D-Climate ModelsNWP Models
High resolution global models(global CRM, MMF)
Global observational datasets
Field campaigns & instrumented sites
How can we gauge and gain confidence in GCMs projections?(1) Bottom-Up approach : evaluate and improve the physical basis of climate models
through large-scale and process-scale evaluations
(2) Top-Down approach : understand the models' results & identify critical processes to provide guidance for specific observational tests/process
studies and model improvements
Analysis & Understandingclimate change
Model projections
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
The second approach has traditionally dominated WGCM’s interests, but this is changing.
• Current activities focus on understanding why model projections differ
e.g., quantifying the strength of individual feedbacks across models.
• Evaluate climate models over a wide range of scales and phenomena
From weather to paleo
From global to regional
From individual physical processes to climate (across all physical and biogeochemical components)
• Explore how model formulation and present-day model performance translate to reliability of climate projections
Perhaps the biggest challenge of all.
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
CMIP3 transformed climate science by enabling community-wide participation in the analysis of model output.
0
100
200
300
400
500
600
700
800
900
1000
1100
12009/26/2009
daily raterunning 31-day mean
date
gig
abyte
s p
er
day
WCRP CMIP3 Archive Download Rates
• 35 Tbytes of model
output stored at PCMDI
• More than 765 TB
downloaded
• More than 3,000 users
• More than 550 publications
Aug 2009Jan 2007(AR4 WGI)
Nov 2004
Courtesy of Bob Drach (PCMDI)
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
What are prospect for CMIP5?
• Better understand robust and uncertain aspects of climate change
Enable quantification of strengths of major feedbacks
• Include carbon cycle component (ESM’s)
• Better meet the needs of the “impacts” community
A more comprehensive set of model output
• Provide information needed to assess adaptation and mitigation strategies
• Coordinate/integrate across the modeling community:
CMIP includes portions of: C4MIP, PMIP, AMIP, CFMIP, Aqua-planet
4th WOAP Meeting29 March 2010
K. E. Taylor
CMIP5: Three Suites of Experiments
“Long-Term”(century & longer)
TIER 1
TIER 2
CORE
evaluation& projection
diagnosis
“Near-Term”(decadal prediction)
(initialized ocean state)
hindcasts & forecasts
CORE
TIER 1
TIER 2
TIER 1
AMIP
“time-slice”
CORE
Atmosphere-Only
(for computationally demanding and NWP models)
TIER 1
TIER 2Taylor et al. 2008,
http://cmip-pcmdi.llnl.gov/cmip5
4th WOAP Meeting29 March 2010
K. E. Taylor
Example: CMIP5 long-term suite of experiments
An important focus is model evaluation and understanding...
D & A
ense
mble
s
Control, AMIP, & 20 C
RCP4.5, RCP8.5
natural-only,
GHG-only
individual
forcing
RCP2.X, RCP6
extend
RC
P4.5 to
2300 extend RCP8.5 &
RCP2.X to 2300
ense
mbl
e of
ab
rupt
4xC
O2
5-yr
run
saqua
planet
(clouds) uniform
ΔSST
(clouds)
Mid
-Hol
ocen
e &
LG
Mlast
m
illen
nium
E-driven RCP8.5
E-driven control & 20 C
patterned
ΔSST
(clouds)
aerosol forcing
ca. 2000
AC&C4
(chemistry)
1%/yr CO2 (140 yrs)
abrupt 4XCO2 (150 yrs)
fixed SST with 1x & 4xCO2
radiation code sees 1xCO
2 (1%/yr or 20C+RCP4.5)carbon cycle sees 1XCO
2 (1%/yr or 20C+RCP4.5)Understanding
Model Evaluatio
n
ClimateProjections
Green subset is for coupled carbon-cycle climate models only
ensembles: AMIP & 20 C
4th WOAP Meeting29 March 2010
K. E. Taylor
CMIP now involves many WCRP/IGBP partners
Example: CMIP5 long-term suite of experiments
Detection-Attribution(IDAG)
Paleo(PMIP, IGBP-
PAGES)
Cloud andmoist processes
(CFMIP-GCSSWGNE)
Carbon-climate feedbacks(C4MIP, IGBP-AIMES)
Integrated AssessmentConsortium (IAM),
connection to WG-III
+ Satellite simulators& process
diagnostics (CFMIP-GCSS)
Chemistry, aerosols(SPARC, AC&C,
CCMVal, aerocom)
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
WGCM (with others) promotes a variety of community-wide activities to advance climate modeling
• Mentioned already:
SPARC & IGBP/IGAC (CCMVal, AeroCom..): chemistry & aerosols
WGCM & IGBP/PAGES (PMIP): paleoclimate
WGCM, GCSS, and WGNE (CFMIP): clouds and cloud feedbacks
WGCM, IGBP/AIMES (C4MIP): carbon cycle
IDAG: detection and attribution studies
• WGNE/WGCM (Transpose-AMIP): evaluation of climate models in NWP mode
• CLIVAR WGSIP, WGOMD : seasonal to interannual prediction, ocean
• TFRCD (CORDEX) : regional
• GEWEX GCSS (GPCI) : processes
• WGNE/WGCM Metrics panel
• CF metadata conventions for archiving and sharing climate data
• WGCM endorsed demonstration study (GeoMIP): geo-engineering
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
WGCM’s Challenge to WOAP
• Push to make observations as easily available and useable as climate model output generated by CMIP.
Provide easy access and guidance on quality and limitations
Following CMIP3, store observational data in a standard way and make it available through a common portal.
• The WGCM has endorsed a NASA/JPL pilot initiative to provide satellite data in a form useful to CMIP5 (Joao Texeira, Duane Waliser, Jerry Potter, S Boland).
• A similar NOAA initiative may be launched soon, and this in the work plans ISENES (a European project to provide infrastructure support for climate model research)
• These new projects were all partially inspired by CMIP
The WGCM would like to see similar efforts undertaken by other providers of satellite and in-situ observations.
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
WGCM’s Challenge to WOAP
• Provide encouragement and possibly a framework whereby
the observational and climate modeling community would interact to identify observational data sets useful in model evaluation
The highest priority would be to consider the CMIP output -– variables, temporal/spatial sampling, time-periods.
• Establish guidelines for
Metadata that will facilitate search and discovery.
Formats and metadata that will facilitate analysis (as provided by the CF metadata standard)
• Develop a strategy for making multiple datasets developed for this purpose accessible in a way that parallels the CMIP model output archive.
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
List of CMIP5 output fields
• http://cmip-pcmdi.llnl.gov/cmip5/output_req.html
• Domains:
Atmosphere (including aerosols)
Ocean (including carbon cycle variables)
Land surface (including carbon cycle variables)
Cryosphere
• Temporal sampling
Annual
Monthly
Daily (including max., min. & mean surf. Air T, precip. humidity, surf. wind, PSL; many more 2-d & 3-d fields for 1950-2005)
6-hourly
3-hourly (including from 1950-2005)
~ half-hour (but not globally)
PCMDI4th WOAP Meeting29 March 2010 K. E. Taylor
Model output characteristics
• Specified template for filenames and directory structure
• Additional metadata
modeling_realm
tracking_id
model_id
creation_date
Forcing
initialization_method,
physics_version
• Output may be on native grid, rather than longitude-latitude cartesian
4th WOAP Meeting29 March 2010
K. E. Taylor
CMIP5 Decadal Prediction Experiments
additional predictions Initialized in
‘01, ’02, ’03 … ’09100-yr “control”
& 1% CO
2
prediction with 2010 Pinatubo-
like eruption
alternative initialization strategies
atmos. chem
istry
&/or aerosols &/or
regional air quality
AMIP
incre
ase
ense
mble
size
s
from
O(3
) to
O(10)
mem
bers
hind
cast
s with
out
volc
anoe
s
30-year hindcast and prediction ensembles: initialized 1960, 1980 &
2005
10-year hindcast & prediction ensembles: initialized 1960, 1965, …,
2005
4th WOAP Meeting29 March 2010
K. E. Taylor
CMIP5 Atmosphere-Only Experiments(targeted for computationally demanding and NWP models)
AMIP(1979-2008)
AMIP
ensemble
AMIP
SSTs
with 4
XCO 2aqua planet
(clouds)
uniform ΔSST
(clouds)
patterned ΔSST
(clouds)
future “time-slice”(2026-2035)
Future “time-slice”
ensemble