Title: The Computational Future for Climate Change Research
1The Computational Future for Climate Change
Research
- Warren M. Washington
- National Center for Atmospheric Research
- Boulder, Colorado
June 2005
2Climate Change Computational Future
- Components Atmosphere, Land-Vegetation, Ocean,
Sea Ice, Surface Hydrology, Biogeochemical cycles
(e.g. carbon cycle) including aerosols, and ice
sheet model - Simulations of recent past and future climate
including the Inter-governmental Panel on Climate
Change (IPCC) simulations - Higher resolutions
- Computational Efficiency
- Various Computational Paradigms
3DOE and NSF support has lead to major
improvements in Community Climate System Model
version 3 (CCSM3.0)
- Complete system
- New portability for vector and Linux
supercomputers systems - Improved physical processes
- Improved methods to run IPCC climate-change
experiments on variety of computers and - Flexibility to simulate climate over a wide range
of spatial resolutions with greater fidelity.
4Timeline of Climate Model Development
Ice Sheet
5Model Resolutions
R15
T42
500 km
300 km
75 km
T170
T85
150 km
6 (300 km)
(150 km)
(75) km
(37 km)
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8View of the Parallel Ocean Program (POP) Model
Horizontal Grid at 2/3o Resolution
Note high resolution in North Atlantic and near
equator
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11Sea-ice Concentration Climatology (1979-1999)
12Global and Regional Climate Aspects Using a
Climate Model
- El Niño/La Niña
- Monsoons
- North Atlantic Oscillation
- Arctic Oscillation
13Sample Trajectory Figures from the 0.1o POP model
showing complex eddies structures
- From
- Julie McClean, Mathew Maltrud, Frank Bryan and
Deterlina Ivanova - Naval Post Graduate School
- Los Alamos National
Laboratory - National Center For
Atmospheric Research
14Numerical Trajectories Salinity particles
released in the GIN Sea
15Numerical Trajectories Salinity particles in
the North Atlantic
16Numerical Trajectories Salinity particles near
Indonesian Seas
17Flow through Indonesian Seas
18River Transport
Coarse Resolution
19Title slide
Mt Pinatubo eruption in the Philippines, June 15,
1991. Gases and solids injected 20 km into the
stratosphere.
From Church, White, Arblaster
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22Barnett et al. SCIENCE, July 8th, 2005
23Climate Change Scenarios At any point in time,
we are committed to additional warming and sea
level rise from the radiative forcing already in
the system. Warming stabilizes after several
decades, but sea level from thermal expansion
continues to rise for centuries. Each emission
scenario has a warming impact. (Meehl et al.,
2005 How much more warming and sea level rise?
Science, 307, 1769-1772)
24(Meehl et al., 2005, GRL, submitted)
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26Climate Change Animation
The following animation depicts warming of the
Earth's surface as simulated by the CCSM. It
shows both regional changes and an average of the
entire globe. The data represents the
temperature difference from the 1870-1900 period,
and is an average of five separate CCSM
experiments, from 1870 to 2100. The future period
is derived from the IPCC A1B scenario. The gray
shading around the global average shows the
spread of the ensemble members. Created by Gary
Strand of NCAR using the Ferret software package.
27By the end of the 21st century, greater warming
occurs at high northern latitudes and over the
continents in the scenario simulations. We are
already committed to about another half a degree
of warming over North America by the year 2100.
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29Changes in N. Atlantic Currents
30Change of Extremes
- Heat waves, cold snaps
- Floods, droughts
- First freeze dates, hard freeze frequency
- Precipitation intensity
- Diurnal temperature
31Pioneering Computation by Ming and Droegemeier of
Un. Of Oklahoma. showing what happens with good
cloud physics and a high enough resolution
- Domain 50 km by 16km
- ?x, ?y25 m, ?z20 m
- 1/3 billion grid points
32This is what you get with a 25 m grid and the
right physics!
33Earth System Model Interactions
Climate and Sea Level
Atmospheric Composition
Atmospheric Chemistry
Climate
Ocean Carbon Cycle
Ocean - temperature - sea level
Ecosystems
Human Activities
Other Human Systems
Terrestrial Carbon Cycle
Energy System
Unmanaged Ecosystem
Agriculture, Livestock and Forestry
Coastal System
Crops and Forestry
Hydrology
34Ongoing and Future Developments
- Higher resolution, especially important near
mountains, river flow, and coast lines - Full hydrological coupling including ice sheets
- Better vegetation and land surface treatments
with ecological interactions - Carbon and other biogeochemical cycles
35New York Times 8 June 2004
36Melting Greenland Glacier This lubricates bottom
of ice. Photo by Roger Braithwaite and Jay
Zwally, NASA
37Lightning natural source and combustion
anthropogenic of nitrate
denitrification
microbes
Coupled Carbon-Nitrogen dynamics
- Strong feedback between decomposition and plant
growth soil mineral nitrogen is the primary
source of nitrogen for plant growth. Nitrogen
fixing bacteria/algae very important, however,
limited field and laboratory data on their role. - Can result in a shift from carbon source to
carbon sink under warming scenario.
P.E. Thornton, NCAR
38Climate Model Problems with Supercomputer Systems
- Computers not balanced between processor speed,
memory bandwidth and bandwidth between processors
including global. - More difficult to program and optimize
- Hard to get I/O out of computers efficiently and
computer facilities need to have expanded
archival capability in the petabyte range. - Little relationship between theoretical
performance and performance on actual working
climate model programs.
39What SciDAC has done for the Climate Modeling
Science
- It has brought new ideas and computational
techniques to the climate modeling community.
(The days of a small group of people putting
together a state-of-art climate model are
limited.) - It has helped with BER to bring together the
expertise of DOE laboratories, universities, and
centers into a coordinated effort. Innovation
still alive and needs to be protected! - It has provided enhanced computing capability to
the nations climate modeling community but
further increased are needed. - Together we are providing scientifically credible
information to the national and international
policymakers.
40News Event
Joint Science Academies statement on 7 June
2005 there is now strong evidence that global
warming is occurring and the scientific
understanding of climate change is now
sufficiently clear to justify nations taking
prompt action
Climate models have helped determine future
environmental and energy strategies by
performing many what if simulations. Bottom
lineSciDAC has improved climate models and
their projections.
41The End
- This project involves the efforts of over 300
scientists and computational experts at DOE
Laboratories, NCAR, and the Universities.
42Next IPCC Schedule2007-9
- Need to get ready
- Petabyte data sets
?
43How do we make progress?
- Finer resolution
- Improved physical processes
- High performance supercomputers
44Analysis of Millennium Temperatures
45Climate models can be used to provide information
on changes in extreme events such as heat
waves Heat wave severity defined as the mean
annual 3-day warmest nighttime minima event
Model compares favorably with present-day heat
wave severity In a future warmer climate, heat
waves become more severe in southern and western
North America, and in the western European and
Mediterranean region Meehl, G.A., and C. Tebaldi,
2004 Science, 305, 994--997.
Observed
Model
Future
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48CCSM3 (Meehl et al., 2005, J. Climate
special issue paper)
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50David Pierce Scripps Institution of Oceanography
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53Change of Extremes
- Heat waves, cold snaps
- Floods, droughts
- First freeze dates, hard freeze frequency
- Precipitation intensity
- Diurnal temperature
54CCSM3 (Meehl et al., 2005, J. Climate
special issue paper)
55Climate Change for 2100
56Science Problems (From G. Assmar, NASA)
- Climates of past geologic periods 102-106
years). - Causes of ice-age climates.
- Effects of alternative parameterizations of
various physical processes in the atmosphere,
ocean, land surface, sea ice, and snow. - Interactions of atmospheric circulations with
photochemistry, especially the carbon cycle. - Interactions of the atmosphere and oceans with
sea ice and continental ice sheets. - El Ni\no, the Southern Oscillation, the Walker
Circulation, North Atlantic and Arctic
Oscillation. - Interannual and intra-annual variability.
- Vegetation changes (for example, those produced
by deforestation). - Causes of changes in monsoon circulations.
- Causes of droughts and the formation of deserts.
- Effects of volcanic eruptions.
- Effects of \cotwo and other trace gases.
- Climate predictions on monthly, seasonal, and
longer time scales. - Effects of natural and anthropogenic aeroso
57Pacific Decadal Oscillation (PDO)
Warm phase
Cold phase
From University of Washington
58Ensemble Simulations
59PCM Observed ENSO pattern
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64From M. Prather University of California at Irvine
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66We are already committed to about as much warming
as we experienced in the 20th century by the year
2100, but over three times as much sea level rise
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71Status of CCSM3
- Bill Collins
- National Center for Atmospheric Research
- Boulder, Colorado
72Topics
- Release of CCSM3
- Simulations for IPCC and paleoclimates
- Improvements in the climate simulation
- Systematic challenges in the simulations
- Extensions to coupled chemistry/climate
- Extensions to higher spatial resolution and
process fidelity
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74Release of CCSM3
- Release Date June 23, 2004
- Contents
- Code
- Input data sets
- Scripts for compilation and execution
- Documentation
- URL http//www.ccsm.ucar.edu/models/ccsm3.0/
- Number of downloads to date Counter
75Supported Resolutions and Platforms
- Scalar Platforms
- IBM SP
- SGI Origin
- Linux (PGI)
- Compaq
- Vector Platforms
- NEC (Earth Simulator)
- Cray X1
T85x1
T42x1 FV 2?2.5
T31x3 .
IPCC
Resolution
AMWG, CVWG, Paleo,
BGCWG, Paleo
Dynamics
76CCSM3 Control Experiments
1990 1780 1870 1CO2 1CO2 2x 1CO2 4x 20th C.
T31x3 748 406 TBD 171 104 107 TBD
T42x1 869 408 110 168/ 214 152 151 TBD
T85x1 611 280 114/ 160 151 44 2000 (5x)
Yellow NCAR Systems Red Earth Simulator
TBD To Be Done
?
77Distribution of CCSM3 Control Runs
- Central site Earth System Grid
- DOE project to integrate major centersfor
supercomputing and analysis - CCSM3 output available
- Current contents Perpetual 1990 runs
- Averaged data sets Open access
- Original history files SCD account holders
- Access point https//www.earthsystemgrid.org/
78CCSM3 Documentation
- New software manuals
- Users guides
- Code references
- New NCAR technical notes
- CAM
- CSIM
- CLM
- DVGM (Dynamic Global Vegetation Model)
- New technical report for POP
79Special Issue of Journal of Climate
- Objectives
- Describe CCSM3 to the climate community
- Document CCSM3 for the IPCC 4th Assessment Report
- Topics
- Overview of CCSM
- Description of features climate state for each
component - Climate sensitivity
- Response of CCSM to paleo, pre-industrial
conditions - Major modes of coupled variability
- Editor Dave Randall
- Deadline November 2004
- Contents 29 papers proposed by seven working
groups
80Special Issue of IJHPCA(International Journal of
High Performance Computing Applications)
- Guest editors
- John Drake (ORNL)
- Phil Jones (LANL)
- Tom Henderson (NCAR)
- Schedule
- May 2004 Call for papers
- Oct. 2004 Deadline for papers
- Fall 2005 Publication of special issue (V.
18,3) - Major topics
- Software engineering for climate models
- Performance and portability of climate model codes
81The Experimental Configuration
- Three phases
- Pre-industrial (1870)
- 20th Century (1870-2000)
- Emissions Scenarios
- SRES Scenarios
- Commitment (20th C. CO2)
- 2000-2100 (5 runs)
- 2100-2200 (1 run)
- A1B and B1 Scenarios
- 2000-2100 (5 runs)
- 2100-2200 Const (5 runs)
- 2200-2300 Const (1 run)
- A2 Scenario
- 2000-2100 (5 runs)
82Experimental Design
Forcing 20th Century 21st-23rd Century
Greenhouse Gases Observed SRES
Ozone Trop MOZART Strat Solomon Trop MOZART scaled by O3 TAR forcing Strat Solomon
Sulfate Aerosols SO2 Smith/Wigley SO2 SRES
Carbon Aerosols Population Scaling SO2 Scaling
Sea-salt Dust Year 2000 values Year 2000 values
Volcanic Aerosols Ammann (2003) Year 2000 values
Solar Variation Lean (1995) Year 2000 values
Indirect Effects None None
83Aerosol Optical Depths
Sulfates
Black Organic Carbon
Strat. Volcanics
84Comparison of CCSM3 and Global Surface
Temperatures
CCWG/Arblaster
85Component Models
- Atmosphere
- Land-Vegetation
- Ocean
- Sea Ice
- Biogeochemical Cycles (e.g. Carbon cycle)
- Ice Sheet
- Regional Model Coupling
86Projections for the 21st Century
A1B Scenario
B1 Scenario
Commitment
?
Kyosei Consortium
87Transient Climate Sensitivity from CCSM3
88SST Biases in W. Coastal Regions
?
89Equilibrium Sensitivity from CAM3 SOM
Kiehl and Shields
90Equilibrium Climate Sensitivity
Kiehl and Shields
91Cloud Radiative Response to 2xCO2
Kiehl and Shields
92CCSM3 Surface TemperatureGlobal/Annual Mean
Coupled
Slab ocean
- 2.8C
- 5.7C
- 5.9C
Otto-Bliesner
93Land Use as a Climate Forcing
Much of the present-day natural vegetation has
been cleared for agricultural land. By 2100,
there is likely to be further expansion of
agricultural land in North America, South
America, Africa, and Southeast Asia What is the
land use forcing relative to other natural and
anthropogenic forcings?
Undisturbed
1970
2100
Participants LMWG, CCWG, and NCAR Biogeosciences
and Assessment initiatives
94Simulations for Present-Day ConditionsCCSM3 vs.
CCSM2
95Effects of the Ocean Diurnal Cycle
Observations
CCSM3 with Cycle
CCSM3 without Cycle
96Effects of Chlorophyll Absorption
Heating By Chlorophyll
?
97Effects of Resolution on Sea-Ice Thickness
T85?1
T42?1
T85?1 ? T42?1
98Effects of New CAM Physics on Temperatures
CAM2 T42
NCEP
CAM3 T42
CAM2 T42
CAM2 - NCEP
CAM3 CAM2
99Improved Cloud Response to ENSO
CAM3 T42 AMIP
CAM3 T42 AMIP
CAM2 T42 ERBE
ERBE
100Improvements in Surface Radiation over Sea-Ice
Shortwave Flux
Observations
Longwave Flux
101Semi-Annual SST Cycle
Anomaly Observations
Anomaly T85?1
102Periodicity of ENSO
NCEP Monthly Nino 3.4 ?0.82 K
T85?1 Monthly Nino 3.4 ?0.77 K
?
103Double ITCZ Issue
104Excessive Ice in FV Coupled Runs
FV2?2.5?1
T85?1
FV2?2.5?1?T85 ?1
105Continental Precipitation Biases
Large dry precipitation biases in southeast U.S.,
Amazonia, and SE Asia could adversely affect the
terrestrial carbon cycle
106Continental Temperature Biases
Large (6-10ºC) winter warm temperature biases in
the Arctic could adversely affect the terrestrial
carbon cycle
107Multi-Century Coupled Carbon/Climate Simulations
2.0
14.1
13.6
-2.0
Net CO2 Flux (Pg C/yr)
Surface Temp.
- Fully prognostic land/ocn BGC and
carbon/radiation - Atm-Land 70 PgC/yr ?? Atm-Ocean 90 PgC/yr ??
- Net Landocean 0?1 PgC/yr
- Stable carbon cycle and climate over 1000y
- Projection of climate change on natural modes
- Detection attribution
- Future climate projections/fossil fuel
perturbations
Doney and Fung
108Response of Terrestrial Carbon to Interactive
Nitrogen Deposition
A2 Scenario
2000
2100
Wet deposition
NEE response to 1 C step change
Dry
Sink
Coupled C-N model
Nitrogen deposition likely to increase in
future Including nitrogen in terrestrial carbon
model can change sign in carbon dioxide flux!
C-only model
Source
?
Mahowald and Thornton
109Simulations with CLM-CN for 275 years
Leaf carbon pool (gC/m2) Captures the essential
global details of canopy distribution
Net Ecosystem productivity (gC/m2d) Boreal zone
still accumulating carbon.
CLM3-CN operating in C-only mode for rapid
spinup (Peter Thornton, NCAR)
110Offline Transport Modeling in CCSM3
Offline CAM3
MOZART
- Comparison of passive tracer concentrations at
500 mb - Advection using NCEP fields for 30 days
- Tracer initialized to unity at 700 mb
Hess and Rasch
111Prognostic Aerosols
Seasonal Cycle of Prognostic Dust Optical Depth
- Aerosol Species
- Sulfates
- Nitrates
- Dust
- Sea Salt
- BC and OC
Mahowald
112Response of Ocean Biogeochemistry to Changes in
Iron Deposition
Changes in mineral aerosol deposition due to
climate change interacts with ocean uptake of
carbon through iron limitation and nitrogen
fixation ? changes ocean carbon uptake in future.
Mahowald
113Differences in Ozone due to Dynamics
114Reactive Tropospheric Ozone Chemistry
Lamarque
115High Resolution Ocean Modeling
?
116Entrain More Hydrologists In Model Development
Participants Dennis Lettenmaier (University of
Washington) Eric Wood (Princeton
University) LMWG and NCAR Water Cycle
initiative Gordon Bonan (NCAR) David Gochis
(NCAR) David Yates (NCAR) Keith Oleson (NCAR)
Goal The Variable Infiltration Capacity (VIC)
model is a leading macroscale hydrologic model.
We want to bring the VIC hydrology into the CLM
to improve the simulation of the hydrologic cycle
117Improved SLP Teleconnections for ENSO
118Conclusions
- CCSM3 has been released to the community.
- IPCC simulations are well underway.
- Analysis has begun for
- Characterization of the simulated climate
- Climate sensitivity
- Climate forcing for the 20th century
- Challenges ahead
- Process-oriented modeling of the climate
- Coupled chemistry/climate modeling
119Sensitivity of Carbon to Dynamics
120Global carbon budget, 275-year offline CLM spinup
GPP
NPP
AR
Interannual range in components
HR
NEE
Sym Description PgC/y
GPP Gross primary production 14.0
AR Autotrophic respiration 12.0
NPP Net primary production 6.5
HR Heterotrophic respiration 4.0
NEE Net ecosystem exchange 6.5
CLM3-CN operating in C-only mode for rapid spinup
(Peter Thornton, NCAR)
121Meridional Overturning CirculationAtlantic Ocean
CCSM3
CSM1
LGM
Pre Industrial
Otto-Bliesner
122Acceleration of CCSM3 CAM3
123Vectorization of CLM
124LGM (21K BP) Seasonal Cycles
125Vectorization of CAM3
126More Components
- Sea ice-viscous-plastic Hibler dynamics with
relaxation, or elastic-viscous-plastic, 27 km
resolution - Parallel flux coupler ties components together
127Relationship Between North Australian Rainfall
and the Decadal Pacific Oscillation
Observations correlation -0.8
PCM correlation -0.5
128LGM (21K BP) Land-Ice Extent
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130Deep/Abyssal Northwest Atlantic
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135Major Improvements in CCSM3.0
- Atmosphere
- New treatments of the condensed water and
geometry of clouds - Improved treatments of cloud droplets and ice
particles - Improved representation of the interactions among
water vapor, solar radiation, and terrestrial
thermal radiation - New treatment of the effects of aerosols on the
reflection and absorption of solar radiation and
- New dynamical frameworks suitable for modeling
atmospheric chemistry - Coupler
- Improved performance and scalability on parallel
supercomputers - Faster multi-way communication among the
component models and - New communications infrastructure
136Major Improvements in CCSM3.0
- Land
- New methods to enable simulation of the
terrestrial carbon cycle - New methods to enable simulation of dynamic
vegetation and - Improvements in land-surface physics to reduce
temperature biases - Ocean
- Improvements to the representation of the ocean
mixed layer - Inclusion of solar heating by chlorophyll and
- New infrastructure for studying vertical mixing
in the ocean - Sea-ice
- Improved schemes for horizontal advection of sea
ice - More realistic treatments of snow and ice
reflectivity and - Updated treatments for sea-ice thickness