Climate Initiatives and Climate Initiatives and OpportunitiesOpportunities

J. J. Hack (NCCS)J. J. Hack (NCCS)

ClimateClimate

Global climate is driven by energy from the Sun and modulated Global climate is driven by energy from the Sun and modulated by atmospheric compositionby atmospheric composition

Carbon Dioxide (ppm) Methane (ppb)

Nitrous Oxide (ppb)

Rad

iati

ve F

orc

ing

(W

m-2)

Rad

iati

ve F

orc

ing

(W

m-2)

Rad

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ve F

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ing

(W

m-2)

Changing Atmospheric Composition:

Indicators of the Human Influence

Global Mean Surface Temperature AnomaliesGlobal Mean Surface Temperature Anomalies

Summary for Policymakers (IPCC AR4)Global and Continental Temperature Change

Summary for Policymakers (IPCC AR4)Global and Continental Temperature Change

Regional Impacts of Climate ChangeRegional Impacts of Climate Change

Mote et al 2005

Observed Change 1950-1997Observed Change 1950-1997 SnowpackSnowpack TemperatureTemperature

(- +)

(- +)

Regional Climate Change

Regional Climate Change

DJF

2080-2099 (A1B) - 1980-1999

Precipitation (%)

# of Modelswith ΔP > 0

JJA

Climate changeand its

manifestation in terms of

weather(climate extremes)

Extreme EventsExtreme EventsStorms, Floods,Storms, Floods,Droughts, CyclonesDroughts, Cyclones

More frequent droughts and periods of intense More frequent droughts and periods of intense precipitationprecipitation

Direct loss of life and injuryDirect loss of life and injury Indirect effectsIndirect effects

– Loss of shelterLoss of shelter– Population displacementPopulation displacement– Contamination of water suppliesContamination of water supplies– Loss of food productionLoss of food production– Increased risk of infectious disease epidemics (diarrhoeal Increased risk of infectious disease epidemics (diarrhoeal

and respiratory)and respiratory)– Damage to infrastructure for provision of health servicesDamage to infrastructure for provision of health services

Atmospheric Motion SpectraAtmospheric Motion Spectra

Nastrom and Gage (1985)

>106 operation count

Atmospheric Energy TransportAtmospheric Energy TransportSynoptic-scale mechanisms

extratropical storms

http://www.earth.nasa.gov

Capturing Primary Phenomenological Capturing Primary Phenomenological Scales of Motion in Global ModelsScales of Motion in Global Models

High Resolution Climate High Resolution Climate SimulationSimulation

Column Integrated Water Vapor

Effect of Systematic Errors

• Efforts to reduce systematic errors crucial – biases affect both a model’s climate sensitivity and also utility as a predictive tool

• Approaches: (1) improve existing physical parameterizations (2) more accurate incorporation of phenomena

• A working hypothesis is that the internal dynamics of the system are more accurately represented at higher resolutionResolving tropical instability waves

Improving Climate Models

Process Models and ParameterizationProcess Models and Parameterization

Improving Climate ModelsUpscaling Research

• Basic requirement: the research community needs to gain considerable experience running models in climate mode with mesoscale processes resolved, together with theoretical and diagnostic efforts, to:

improve understanding of multiscale interactions in the coupled system

identify those of greatest importance and those that require more data to understand

document their upscaling effects on climate

identify those processes that can be parameterized, and those that cannot

Atmosphere Ocean

Coupler

Sea IceLand

CCSM Example: Evolution toward an ESM

• Coupled climate-chemistry model in the immediate future

Terrestrial and oceanic biogeochemical models Ocean ecosystem and terrestrial C/N models Ability to simulate interactions of aerosols with water and

biogeochemical cycles

• Explore and understand importance of upper atmospheric process

• Land use and land cover change

C/NCycle

Dyn.Veg.

Ecosystem & BGCGas chem. Prognostic

AerosolsUpperAtm.

LandUse

LandIce

Science OpportunitiesScience Opportunities Decadal prediction on regional scales Decadal prediction on regional scales

– Accuracy in global modelsAccuracy in global models

Climate extremes (heat waves, drought, floods, synoptic events, etc.)Climate extremes (heat waves, drought, floods, synoptic events, etc.) Climate variability (low frequency variability)Climate variability (low frequency variability) Water cycle, particularly in the tropicsWater cycle, particularly in the tropics

– Potential impacts on biofuelsPotential impacts on biofuels

– Interactions of the water cycle on mitigation and adaptation strategyInteractions of the water cycle on mitigation and adaptation strategy

– Amplifier on carbon cycle response to global warmingAmplifier on carbon cycle response to global warming

Human induced impacts on carbon cycle Human induced impacts on carbon cycle – Half impacts are taken up by the system (will that change?)Half impacts are taken up by the system (will that change?)

– How will climate change affect the carbon cycle?How will climate change affect the carbon cycle?

Sea level riseSea level rise– Melting of the Greenland and Antarctic ice sheetsMelting of the Greenland and Antarctic ice sheets

Abrupt climate change Abrupt climate change

ModelsModels

Carbon cycleCarbon cycle Forcing terms that represent multiscale nature of Forcing terms that represent multiscale nature of

problemproblem– e.g., water cyclee.g., water cycle

Need for evaluation infrastructure (accelerate Need for evaluation infrastructure (accelerate prototyping process)prototyping process)– Test casesTest cases– Data for evaluationData for evaluation– Staged increases in complexityStaged increases in complexity– Modularized functionalityModularized functionality

Validation and Verification testsValidation and Verification tests

ObservationsObservations

Carbon cycle measurements activitiesCarbon cycle measurements activities– Unique opportunity to integrate measurements into modelsUnique opportunity to integrate measurements into models

– Enhanced process modeling for incorporation in component modelsEnhanced process modeling for incorporation in component models

Assimilation systems for chemical and biogeochemical observationsAssimilation systems for chemical and biogeochemical observations– Use of in situ and satellite observationsUse of in situ and satellite observations

Continued investments in targeted process studies like ARMContinued investments in targeted process studies like ARM

– Decade of experience in fielding complex observational systemsDecade of experience in fielding complex observational systems

– Resolve continuing uncertainties about clouds, aerosols, and radiationResolve continuing uncertainties about clouds, aerosols, and radiation

Computational AlgorithmsComputational Algorithms

Scalable isotropic dynamical coresScalable isotropic dynamical cores– dynamic load balancing capabilitiesdynamic load balancing capabilities

Alternative vertical discretizationsAlternative vertical discretizations Implicit or large time step discretizationsImplicit or large time step discretizations Robust grid remapping algorithmsRobust grid remapping algorithms Assimilation methodologiesAssimilation methodologies

– Ocean, carbon cycle, …Ocean, carbon cycle, …

– adjoints, ensemble Kalman filters, …adjoints, ensemble Kalman filters, …

Need to address multiscale scienceNeed to address multiscale science– Variable resolution refinementsVariable resolution refinements

– Uniform high-resolutionUniform high-resolution

Error estimation techniquesError estimation techniques

ProductionProduction Quality Software Quality Software High-performance parallel I/O standardHigh-performance parallel I/O standard Future programming modelsFuture programming models

– MPI/OpenMP replacementsMPI/OpenMP replacements

– Methodologies and tools required to exploit highly parallel architecturesMethodologies and tools required to exploit highly parallel architectures performance analysis toolsperformance analysis tools librarieslibraries

– Tools for refactoring application codes Tools for refactoring application codes

– Language improvementsLanguage improvements

Componentization Componentization – verification; unit testing, …verification; unit testing, …

Scalable and distributed analysis softwareScalable and distributed analysis software Math and application frameworksMath and application frameworks Benefits to partnerships in development of software environmentBenefits to partnerships in development of software environment

– DOE needs to exercise more control of the broader activityDOE needs to exercise more control of the broader activity

– Substantial investment in software for current and future machines a prioritySubstantial investment in software for current and future machines a priority

SummarySummary

Global Climate ModelingGlobal Climate Modeling– complex and evolving scientific problem complex and evolving scientific problem – Better parameterizations of physical processes are pacing progressBetter parameterizations of physical processes are pacing progress

these are not necessarily well posed problemsthese are not necessarily well posed problems

– observational limitations are pacing process understandingobservational limitations are pacing process understanding this has ALWAYS been an important rate-limiting componentthis has ALWAYS been an important rate-limiting component

– computational limitations pacing exploration of model formulationscomputational limitations pacing exploration of model formulations explorations of resolution parameter space, process modeling, system explorations of resolution parameter space, process modeling, system

sensitivities, model validation (e.g., reproduce paleo record)sensitivities, model validation (e.g., reproduce paleo record)

Many scientific and technical opportunities Many scientific and technical opportunities

ORNL is assembling infrastructure with which to partnerORNL is assembling infrastructure with which to partner

– both technical and intellectual partnerships across wide range of science both technical and intellectual partnerships across wide range of science

interestsinterests

The EndThe End