Global Change: New Operations and Modeling Challenges

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Global Change New Operations and Modeling
Challenges

• Ants Leetmaa
• Geophysical Fluid Dynamics Laboratory
• National Oceanic and Atmospheric Administration
• Princeton, NJ

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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

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• 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

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Possible Global Warming Impacts
Annual Surface Air Temperature (deg C)
These changes will present new opportunities and
threats
Conditions at double pre-industrial values of
CO2 GFDL model
Winter runoff (cm/yr)
Annual change in runoff (cm/yr)
Summer Soil Moisture (cm)
Wetter
Drier
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Possible Hazards -Summer 2030 hot, dry and
unhealthy (after 7th consecutive year of droughts)
Major fires
Agricultural production at 50, blowing dust
Health warning Limit outdoor activities expect
brownouts
major fisheries regime change likely
Air quality alerts 75 of days
Swimming and Fishing prohibited
Frequent floodings and Asian dust threats continue
High danger of toxic CO2 releases
African bacteria alerts
Expect fisheries downturn health threats
ALERT FORECASTs US Economy code orange US
health code orange International Economy
code red Global Security code red
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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

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Extending the Product SuiteInstitutional
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.

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Some Issues to Ponder

• What will be NOAAs most important future product
  suites? (hint economy, health, environment)
• How will you develop the appropriate modeling and
  product delivery mechanisms? (hint it wont all
  be done in house)
• How are you going to work with the rest of NOAA
  to meet these future challenges

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The U.S. Experiences Strong Decadal Fluctuations
in Climate

• Major features were
• Warm 1950s and 1990s
• Cool 1960s and 1970s

• These resulted from
• Natural climate variability
• Anthropogenic causes
• Volcanic and solar effects

Wintertime Surface Temperature Anomalies (deg. C)
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NOAA Uses Computer Models to Develop a Predictive
Understanding of Climate Fluctuations
Observed
Model
1960-1980
1980-2000
GFDLs model simulates U.S. temperature changes
when forced with observed ocean temperatures -
same model is used for ENSO fcsts
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Improved Predictive Understanding Leads to a
Decadal Forecasting Capability and Increased
Confidence in Global Warming Projections
A prediction starting in 1860 forced with
observed radiative forcings - note cool 60s70s
with rapid warming in 1990s
Model forced with observed ocean temperatures
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Decadal Average Wintertime Temperature Anomaly
for U.S. (deg C.)
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
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Seasonality of Long Term Temperature Trends
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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)

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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 doesnt 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.)

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End
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Predictability of Atmospheric VariationsPresent
and Future

• Tony Rosati and Gabriel Vecchi
• Geophysical Fluid Dynamics Laboratory
• NOAA/OAR
• Princeton, NJ 08542

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Climate Scenarios Being Run for 2007 IPCC
What can we learn from these about the slow and
fast modes of climate variations?
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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)

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Changes to Hadley and Walker Circulations
( 500 mb vertical velocity field)
change
1860 Mean
1860
2X
4x minus 1860
2x
Slow down of tropical/subtropical circulations
associated with redistributions of tropical
rainfall
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Changes in Mean Annual Cycle DJF
Note the development of a zonally and
hemispherically symmetric component to the
circulation anomalies with strong impacts in
midlatitudes
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Changes in Mean Annual Cycle SON
The poleward expansion of the subtropical highs
is most pronounced in fall and summer. 1860
relative to 1990 shows equatorward movement of
highs.
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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)

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Changes to Tropical Variability with Planetary
Warming
Increasing CO2
NINO3 SST
reversed 1860 spinup
1990 CO2
CO2 increasing 1/yr
0.5
1
Power Spectrum
Period (yr)
2
4
8
135yr
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NINO3 SST Spectrum Changes
Period (years)
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Changes to Spatial Structure and Amplitude of ENSO
(As evidenced in 500 mb vertical velocity field)
4X
2X
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Changes in Amplitude of ENSO Teleconnections DJF