Use of Regional Climate Models in Impacts Assessments

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Use of Regional Climate Models in Impacts
Assessments

• L. O. Mearns
• Institute for the Study of
• Society and the Environment
• National Center for Atmospheric Research
• Colloquium on Climate and Health
• Boulder, Colorado
• July 17, 2006

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Elevation (meters)
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RegCM Topography 0.5 deg. by 0.5 deg.
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Elevation (meters)
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NCAR CSM Topography 2.8 deg. by 2.8 deg.
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Resolutions Used in Climate Models

• High resolution global coupled ocean-atmosphere
  model simulations are not yet feasible ( 250 -
  300 km)
• High resolution global atmospheric model
  simulations are feasible for time-slice
  experiments 50-100 km resolution for 10-30
  years ( 100 km)
• Regional model simulations at resolution 10-30
  km are feasible for simulations 20-50 years ( 50
  km)

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Benefits of High Resolution Modeling

• Improves weather forecasts (e.g., Kalnay et al.
  1998), down to to 10 km and improves seasonal
  climate forecasts, but more work is needed
  (Mitchell et al., Leung et al., 2002).
• Improves climate simulations of large scale
  conditions and provides greater regional detail
  potentially useful for climate change impact
  assessments
• Often improves simulation of extreme events such
  as precipitation and extreme phenomena
  (hurricanes).

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Regional Climate Modeling

• Adapted from mesoscale research or weather
  forecast models. Boundary conditions are provided
  by large scale analyses or GCMs.
• At higher spatial resolutions, RCMs capture
  climate features related to regional forcings
  such as orography, lakes, complex coastlines, and
  heterogeneous land use.
• GCMs at 200 250 km resolution provide
  reasonable large scale conditions for downscaling.

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Regional Modeling Strategy

• Nested regional modeling technique
• Global model provides
• initial conditions soil moisture, sea surface
  temperatures, sea ice
• lateral meteorological conditions (temperature,
  pressure, humidity) every 6-8 hours.
• Large scale response to forcing (100s kms)
• Regional model provides finer scale response (10s
  kms)

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Now that we can have more regional detail, what
difference does it make in any given impacts
assessment? What is the added value? Do we have
more confidence in the more detailed results? How
important is spatial scale versus other factors
regarding simulating future climate?
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Use of Regional Climate Model Results for Impacts
Assessments

• Agriculture
• Brown et al., 2000 (Great Plains U.S.)
• Guereña et al., 2001 (Spain)
• Mearns et al., 1998, 1999, 2000, 2001, 2003,
  2004
• (Great Plains, Southeast, and
  continental US)
• Carbone et al., 2003 (Southeast
  US)
• Doherty et al., 2003 (Southeast US)
  
• Tsvetsinskaya et al., 2003
  (Southeast U.S.)
• Easterling et al., 2001, 2003 (Great Plains,
  Southeast)
• Thomson et al., 2001 (U.S. Pacific Northwest)
• White et al., 2006 (California
  (wine))

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Use of RCM Results for Impacts Assessments 2

• Water Resources
• Leung and Wigmosta, 1999 (US Pacific Northwest)
• Stone et al., 2001, 2003 (Missouri River
  Basin)
• Arnell et al., 2003 (Southern
  Africa)
• Miller et al., 2003 (California)
• Payne et al., 2004 (Columbia River
  Basin)
• Wood et al., 2004 (Pacific Northwest)
• Forest Fires
• Wotton et al., 1998 (Canada Boreal
  Forest)
• Human Health
• Hogrefe et al., 2004 (New York City)

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Examples of RCM Use in Climate and Impacts
Studies

• Water Resources Pacific Northwest
• Agriculture Wine Production in US
• Human Health New York
• European Prudence Program
• New Program NARCCAP

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ACPI Climate Change Studies

• One control and 3 ensemble future PCM simulations
  were used to drive the RCM for current and
  2040-2060
• Goal Examine the effects of climate change on
  water resources in the western US

Leung et al., 2004
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Global and Regional Simulations of SnowpackGCM
under-predicted and misplaced snow
Regional Simulation
Global Simulation
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Climate Change Signals
Temperature
Precipitation
PCM
RCM
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Effects of Climate Change on Water Resources of
the Columbia River Basin

• Change in snow water equivalent
• PCM - 16
• RCM - 32
• Change in average annual runoff
• PCM 0
• RCM - 10

Payne et al., 2004
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Changes in Extremes A2 scenario RegCM3 nested
in FV-GCM
Changes in T95 event frequency (days per year)
and T95 mean heat wave length (days per event)
Diffenbaugh et al., 2005
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Climate Change and Wine Production in the US
Extreme heat could, by the end of the 21st
century, result in loss of 80 percent of wine
growing area in the US. Significant shift in wine
growing areas, to the Northwest and Northeast.
Current wine growing areas in California, for
example, would no longer be viable areas for
wine production.
White et al., 2006
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Modeling the Impact of Global Climate and
Regional Land Use Change on Regional Climate and
Air Quality over the Northeastern United States

• C. Hogrefe, J.-Y. Ku, K. Civerolo, J. Biswas, B.
  Lynn, D. Werth, R. Avissar, C. Rosenzweig, R.
  Goldberg, C. Small, W.D. Solecki, S. Gaffin, T.
  Holloway, J. Rosenthal, K. Knowlton, and P.L.
  Kinney

Hogrefe et al., 2004
U.S. EPA STAR Program
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NY Climate Health ProjectProject Components

• Model Global Climate
• Model and Evaluate Land Use
• Model Regional Climate
• Model Regional Air Pollution (ozone, PM2.5)
• Evaluate Health Impacts (heat, air pollution)
• For 2020s, 2050s, and 2080s

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Global Climate Model NASA-GISS
IPCC A2, B2 Scenarios
meteorological variables
Regional Climate ClimRAMS MM5
reflectance stomatal resistance surface
roughness
heat
Public Health Risk Assessment
meteorological variables temp., humidity, etc.
Land Use / Land Cover SLEUTH, Remote Sensing
Ozone PM2.5
Air Quality MODELS-3
IPCC A2, B2 Scenarios
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Model Setup

• GISS coupled global ocean/atmosphere model driven
  by IPCC greenhouse gas scenarios (A2 high CO2
  scenario presented here)
• MM5 regional climate model takes initial and
  boundary conditions from GISS GCM
• MM5 is run on 2 nested domains of 108km and 36km
  over the U.S.
• CMAQ is run at 36km to simulate ozone
• 1996 U.S. Emissions processed by SMOKE and for
  some simulations - scaled by IPCC scenarios
• Simulations periods June August 1993-1997
• June August 2053-2057

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Daily Maximum O3 Predictions July 9 - 14, 1996
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Tests with 12 and 4 km Resolution
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Changes in Ozone with Climate Change
2020
Current (ppb)
2080
2050
Hogrefe et al. 2004
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Putting spatial resolution in the context of
other uncertainties

• Must consider the other major uncertainties
  regarding future climate in addition to the issue
  of spatial scale what is the relative
  importance of uncertainty due to spatial scale?
• These include
• Specifying alternative future emissions of ghgs
  and aerosols
• Modeling the global climate response to the
  forcings (i.e., differences among GCMs)

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Programs Exploring Multiple Uncertainties

• PRUDENCE - over Europe
• NARCCAP over North America
• CREAS Cenários REgionais de Mudança de Clima
  para América do Sul
• (Regional Climate Change Scenarios for South
  America)

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PRUDENCE Project

• Multiple AOGCMs and RCMs over Europe Simulations
  of Future Climate

Christensen et al., 2006
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Summary of RegCM3Results for A2 and B2
scenariosNested in HADAM3 time-slice

• RegCM3 50 km
• HadAM3 time slice
• 100 km
• Years 1961-1990 vs. 2070 2099
• A2 and B2 SRES scenarios

Giorgi et al., 2004
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Summer Temperature Change B2 A2 Scenarios
JJA HadAMH B2
JJA RegCM B2
WARM
WARM
JJA RegCM A2
JJA HadAMH A2
WARM
HOT
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NARCCAP North American Regional Climate Change
Assessment Program

• Multiple AOGCM and RCM Climate Scenarios Project
  over North America

www.narccap.ucar.edu
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Participants

• Linda O. Mearns, National Center for Atmosheric
  Research,
• Ray Arritt, Iowa State, Daniel Caya, OURANOS,
  Phil Duffy, LLNL, Filippo Giorgi, Abdus Salam
  ICTP, William Gutowski, Iowa State, Isaac Held,
  GFDL, Richard Jones, Hadley Centre, Rene
  Laprise, UQAM, Ruby Leung, PNNL, Doug Nychka,
  NCAR Jeremy Pal, ICTP, John Roads, Scripps,
  Lisa Sloan, UC Santa Cruz, Ron Stouffer, GFDL,
  Gene Takle, Iowa State, Bill Collins, NCAR,
  Francis Zwiers, CCCma

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Main NARCCAP Goals

• Exploration of multiple uncertainties in
  regional model and global climate model
  regional projections
•   Development of multiple high resolution
  regional climate scenarios for use in impacts
  models
•  

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NARCCAP domain
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NARCCAP PLAN
A2 Emissions Scenario
HADAM3 link to European Prudence
GFDL
CCSM
CGCM3
1960-1990 current
2040-2070 future
Provide boundary conditions
CRCM Quebec, Ouranos
RegCM3 UC Santa Cruz ICTP
HADRM3 Hadley Centre
RSM Scripps
WRF NCAR/ PNNL
MM5 Iowa State/ PNNL
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Global Time Slice / RCM Comparison at same
resolution (50km)
A2 Emissions Scenario
GFDL AOGCM
CCSM
Six RCMS 50 km
CAM3 Time slice 50km
GFDL Time slice 50 km
compare
compare
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Final Thoughts

• Exploration of multiple uncertainties
• Establishing greater confidence in high
  resolution simulations