Dr. Lawrence BujaNational Center for Atmospheric Research

Boulder, Colorado, USA

Dr. Lawrence BujaNational Center for Atmospheric Research

Boulder, Colorado, USA

New Directions in Climate Research and Simulation:

IPCC AR5 and US/NCAR Climate Modeling Activities

New Directions in Climate Research and Simulation:

IPCC AR5 and US/NCAR Climate Modeling Activities

Image courtesy of Canada DND

Recently, the direction of our climate change research program dramatically changed.

WAS: Is anthropogenic climate change occurring?

NOW: What will be the of impact of anthropogenic climatechange on coupled human and natural systems?

• Magnitude and speed?• Direct and indirect impacts?• Adaptation vs mitigation • What are our options & limits?

Addressing these new, much more complex, questions requires• new approaches & priorities,• new science capabilities,• new collaborators/partners

CCSP 2.1a Mitigation Simulations

MSE3 Climate Topics SummaryDOE’s ten-year vision to use exascale computing to

revolutionize DOE’s approaches to energy, environmental sustainability and security global challenges.

Exascale systems provide and unprecedented opportunity for science to use computation not only as an critical tool along with theory and experiment in understanding the behavior of the fundamental components of nature but also for fundamental discovery and exploration of the behavior of complex systems with billions of components including those involving humans.

Download complete MSE3 Report at http://www.er.doe.gov/ASCR/ProgramDocuments/TownHall.pdf

HPC dimensions of Climate Prediction

Data Assimilation

New Science

Spatial Resolution

Ensemble size

Timescale

Better Science(parameterization → explicit model)(new processes/interactions

not previously included)

(simulate finer details, regions & transients)

(quantify statistical properties of simulation) (decadal prediction/ initial value forecasts)

(Length of simulations * time step)

Lawrence Buja (NCAR) / Tim Palmer (ECMWF)

Spatial Resolution (x*y*z)

Ensemble size

Timescale (Years*timestep)

TodayTerascale

5

50

500

Climate Model

70

102010

Petascale

1.4°160km

0.2°

22kmAMR

1000

400

1Km

Regular 10000

Earth System Model

100yr*

20min

1000yr*3min 1000yr * ?

Code Rewrite

Cost Multiplier

Data Assimilation

ESM+multiscale GCRMNew Science Better Science

HPC dimensions of Climate Prediction

?

Lawrence Buja (NCAR)

10

1010

10

10 10

10

2015

Exascale

T42 2.8°

FV 2.0°

T85 1.4°

FV 1.0°

T170 0.7°

FV 0.5°T340 .36° FV 0.25° FV 0.1°

0

50

100

150

200

250

300

Hor

izon

tal G

rid

Siz

e (K

m)

310k m

220k m

160k m

110k m

78k m

55k m

39k m 28k m11k m

Lawrence Buja (NCAR)

GlobalGeneral Atm/Ocn

Circulation

Continental Scale Flow

Carbon Cycle + BGC Spinups

RegionalMJO/MLC

Convergence

IPCC AR3

1998

IPCC AR4

2004 4TF

Sub-RegionalHurricanes

IPCC AR52010 500TF

CCSM Grand Challenge

2010 1PF

CCSM at ¼ ° ATM 1/10°OCN

Courtesy Dr. David Bader, PCMDI/LLNL/DOE

IPCC AR4 Modeling Centers & AR5 Timeline

• Aerosols– Direct and indirect effects

• Chemistry – Radiative and air quality issues

• Dynamic Vegetation– Regrowth following disturbance

• Carbon & Nitrogen Cycle– Ocean & land biogeochemistry – Anthropogenic (transient) land use/cover

• Land Ice Sheets– Sea level Rise & Abrupt Climate change

New CCSM Components for IPCC AR5

IPCC AR5 (2013) ScenariosThe AR5 process has much greater coordination between IPCC WG-I (Physical Science Basis)> WG-II (Impacts, Adaptation, Vulnerability and WG-III (Mitigation).

1. IPCC “Classic + ” Long-term (Mitigation) Scenarios:  • 100 & 300-year climate change simulations• Medium resolution • Core “required” + optional Tier 1 and Tier 2 simulations• Carbon, Nitrogen & Biogeochemical cycles• 4 Representative Concentration Pathways (RCPs) from IAM community• Quantify investment return of mitigation strategies

2. New: Short-term Climate Change “Adaptation” Simulations:  • Short-term (30-year) climate predictions • Single scenario • High-resolution (0.5° or 0.25° resolution)• Designed for impacts, policy and decision making communities.

NCAR

RCPs in perspective – CO2 emissionsRCPs in perspective – CO2 emissions

-20

0

20

40

60

80

100

12020

00

2010

2020

2030

2040

2050

2060

2070

2080

2090

2100

Em

issi

on

s (G

tCO

2)

MiniCAM 4.5

IMAGE 2.6

AIM 6.0

MES-A2R 8.5

IMAGE 2.9

0

5

10

15

20

25

30

2000

2010

2020

2030

2040

2050

2060

2070

2080

2090

2100

Stabilization range (10-90th percentile)

Baseline range (10-90th percentile)

Post-SRES (min/max)

Selected scenarios (min/max)

( 671ppm, +3.7°, NIES )

( 900ppm, +4.5°, IIASA )

( 550ppm, +---°, PNNL )

( 424ppm, <2°, MNP )( 370ppm, <2°, MNP )

From Moss et al., 2008

NCAR

D & A

ense

mble

s

Control, AMIP, & 20C

RCP4.5 RCP8.5

ensembles: AMIP &

20 C

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

s

Radiation code sees 1XCO2 (1% or RCP4.5)

aqua

planet

unform

ΔSST

Mid

-Hol

ocen

e &

LG

Mlast

m

illen

nium

E-driven RCP8.5E-driven 20 C

patterned

ΔSST

sulfate aerosol

forcing in 2000?

sulfate aerosol

forcing in 1960?

1%/yr CO2 (140 yrs)abrupt 4XCO2 (150 yrs)fixed SST with 1x & 4xCO2

E-driven control with C-cycle

CMIP5 Long-term Experiments

Coupled carbon-cycle climate models only

All simulations except those “E-driven” are forced by prescribed concentrations

Carbon cycle sees 1XCO2 (1% or RCP4.5)

NCAR

CMIP5 Decadal Predictability/Prediction ExpsAdditional predictions

Initialized in ‘01, ’02, ’03 … ‘09

100-yr

“control” &

1% CO2

prediction with 2010

Pinatubo-like eruption

Alternative initialization strategies

regional air quality

More complete

atmos.

chemistry &/or

aerosol treatment

prescribed SST time-slices

extended ensembles

to O(10)

extreme eve

nt

analysis

hindcasts

sans

volca

noes

30 year initialized hindcasts

& predictions O(3)

10 year initialized hindcasts & predictions, O(3)

Temperature at 2030 Averages and Extremes

(IPCC AR4: no C-cycle/dynVeg feedback)

Precipitation at 2030 Averages and Extremes

(IPCC AR4: no C-cycle/dynVeg feedback)

From: Earth System Grid Center for Enabling Technologies: (ESG-CET)

• Petabyte-scale data volumes• Globally federated sites• “Virtual Datasets” created through subsetting and aggregation• Metadata-based search and discovery• Bulk data access• Web-based and analysis tool access• Increased flexibility and robustness

ESG GoalsESG Goals Current ESG SitesCurrent ESG Sites

http://www.earthsystemgrid.orghttp://www.earthsystemgrid.orghttp://www-pcmdi.llnl.govhttp://www-pcmdi.llnl.gov

DATA: Earth System Grid Center for Enabling Technologies (ESG-CET)

For AR5, ESG will be expanded to form a global virtual data center!

NCAR

Towards a Next Generation Climate-Weather-ESM

• Existing and future applications require (at least locally) meso-scale and cloud-scale resolution in a global model

• Current climate models are poor weather models, and current weather models are poor climate models.

• Opportunity to leverage the diverse interests and experience of the climate and weather communities to create and share a next-generation atmospheric simulation system.

• New dynamic grids and solution methods capable of efficient operation on petascale computers

Nested Regional Climate Model

NCAR

North Atlantic and North American Regional Climate Changes

The goal is to simulate the effects of climate change on precipitation across the intermountain West States and tropical cyclones, with a focus on the Gulf of Mexico.

• 36, 12 and 4 km domains nested into CCSM

• 1996-2005, then time slices out to 2050

• Multi-member ensembles for each period

• Dedicated time on NCAR IBM Power 6 (Bluefire) since July:

24 nodes (~20% of total number of processors) 36 (12) km simulations use 128 (256) processors per job Will use 3.9M processor hours through 11/08 ~300 Tb of data (to date); 450 Tb total (including earlier runs)

NCAR

Improving Predictions of Regional Changes in Weather and Climate

The Nested Regional Climate Model

IPCC (2007) IPCC (2013) NRCM

High Resolution Climate Modeling

NCAR

Importance of Resolution

18 storms

25 storms

NCAR

Thanks! Any Questions?

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