Global Change: New Operations and Modeling Challenges

Ants Leetmaa

Geophysical Fluid Dynamics Laboratory

National Oceanic and Atmospheric Administration

Princeton, NJ

OVERVIEW

Grand Challenges for 21st Century

• population growth

• altered biogeochemical cycles

• a changing climate

A prototype forecast in 2030

Existing capabilities to meet the challenge

Institutional challenges for the NWS and NOAA

Population Growth and Associated Issues

•9 billion (B) people by 2050 (50% increase)

•Increasing urbanization into mega-cities – 4B new city dwellers – aging populations

•Food availability requires sustainable increases in food output/hectare of 200-300%

•Energy & Security

•Others•Water availability•health threats – pollution, others

Drier

WetterAnnual change in runoff (cm/yr)

Possible Global Warming ImpactsAnnual Surface Air Temperature (deg C)

Conditions at double pre-industrial values of CO2: GFDL model

Summer Soil Moisture (cm)

Winter runoff (cm/yr)

These changes will present new opportunities and threats

Possible Hazards -Summer 2030: hot, dry and unhealthy (after 7th consecutive year of droughts)

Swimming and Fishing prohibited

African bacteria alertsExpect fisheries downturn; health

threats

Health warning: Limit outdoor activities; expect brownouts

Frequent floodings and Asian dust threats continue

Major fires Agricultural production at 50%, blowing dust

major fisheries regime change likely

Air quality alerts – 75% of days

High danger of toxic CO2 releases

ALERT FORECASTs: US Economy – code orange; US health – code orange; International Economy – code red: Global Security – code red

Next Generation Forecast Products

• Seasonal biomass production• Drought with interactive vegetation• Global atmospheric chemical transports• Health impacts including effects of global and local

aerosol & ozone transports, biomass emissions, and temperature

• Sea level - flooding• Coastal ecosystem health• Fisheries and ecosystem regime change likelihoods• Geo-engineering accidents

Extending the Product Suite:Institutional Challenges

• Your focus on current product delivery will limit investment in new areas

• New products entail risks

• Technology progresses faster than NOAA

• Challenge for NOAA is to develop a common architecture to foster transition to NOAA-next.

Some Issues to Ponder

• What will be NOAA’s most important future product suites? (hint – economy, health, environment)

• How will you develop the appropriate modeling and product delivery mechanisms? (hint – it won’t all be done in house)

• How are you going to work with the rest of NOAA to meet these future challenges

The U.S. Experiences Strong Decadal Fluctuations in Climate

Wintertime Surface Temperature Anomalies (deg. C)

These resulted from•Natural climate variability

•Anthropogenic causes

•Volcanic and solar effects

Major features were•Warm 1950’s and 1990’s

•Cool 1960’s and 1970’s

NOAA Uses Computer Models to Develop a Predictive Understanding of Climate Fluctuations

GFDL’s model simulates U.S. temperature changes when forced with observed ocean temperatures - same model is used for ENSO fcsts

Observed

Model

1960-1980 1980-2000

Improved Predictive Understanding Leads to a Decadal Forecasting Capability and Increased Confidence in

Global Warming Projections

Model forced with observed ocean temperatures

A “prediction” starting in 1860 forced with observed radiative forcings - note

cool 60s&70s with rapid warming in 1990s

Decadal Average Wintertime Temperature Anomaly for U.S. (deg C.)

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1950s 1960s 1970s 1980s 1990s

ObservedSimulatedPredicted

Observed - determined from atmospheric reanalysis

Simulated - model forced with observed ocean temperatures

Predicted - model forced with greenhouse gases, volcanoes, solar fluctuations from 1860 to present

Seasonality of Long Term Temperature Trends

Seasonality of Model Projections

•Seasonality and spatial structure of warming similar in model runs and observations

•Model runs started in 1860 and run forward with “observed’ forcings (GHGs, aerosols, solar, ozone)

Summary

A richness of tropical forced responses are important on a variety of time scales, e.g. ENSO like physics remains important

Hadley and Walker cells slow down with global warming• Tropical convection becomes more zonally symmetric

Seasonal circulation patterns become more zonally symmetric• Subtropical highs expand northward (or southward)– especially summer/fall –

depending on warming (or cooling) of tropics• Mid-latitudes experience greater drying tendencies with warming

Models are starting to be capable of explaining decadal and regional climate variability• this will enable more credible attribution (anthropogenic or natural variability) of

longer term trends

ENSO temporal structure doesn’t change significantly• Suggestion of stronger and longer duration events with warming – predictability

possibly is greater• Increased chances of more “100 year” events• Teleconnection patterns are more robust with warming• Decadal variability of ENSO can confound warming signal and is important in

decadal mid-latitude climate fluctuations (droughts, etc.)

End

Predictability of Atmospheric Variations:Present and Future

Tony Rosati and Gabriel Vecchi

Geophysical Fluid Dynamics Laboratory

NOAA/OAR

Princeton, NJ 08542

Climate Scenarios Being Run for 2007 IPCC

What can we learn from these about the slow and fast modes of climate variations?

Preliminary Results from IPCC 2007 Runs

The slow modes - changes to the general circulation• Hadley and Walker cells• Season means

The fast modes -impacts of change on climate variability (ENSO)

Changes to Hadley and Walker Circulations

2x

1860

1860 Mean

4x minus 1860

% change

Slow down of tropical/subtropical circulations associated with redistributions of tropical rainfall

( 500 mb vertical velocity field)

2X

Changes in Mean Annual Cycle: DJF

Surface temperature

rainfall

Z200U200

Note the development of a zonally and hemispherically symmetric component to the circulation anomalies – with strong impacts in midlatitudes

Surface temperature

rainfall

Z200U200

The poleward expansion of the subtropical highs is most pronounced in fall and summer. 1860 relative to 1990 shows equatorward movement of highs.

Changes in Mean Annual Cycle: SON

Seasonality of Model Projections

•Seasonality and spatial structure of warming similar in model runs and observations

•Model runs started in 1860 and run forward with “observed’ forcings (GHGs, aerosols, solar, ozone)

Changes to Tropical Variability with Planetary Warming

reversed 1860 spinup 1990 CO2 CO2 increasing 1%/yr

NIN

O3

SS

TP

ower

Spe

ctru

m

1

4

0.5

2

8

Increasing CO2

Period (yr)

135yr

NINO3 SST Spectrum Changes

Period(years) 1860

1990

greenhouseobs

Changes to Spatial Structure and Amplitude of ENSO(As evidenced in 500 mb vertical velocity field)

2X

4X

Changes in Amplitude of ENSO Teleconnections: DJF