PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Regional Climate Modeling: A Tool for Decision-Makers Eugene S. Takle Agronomy Department Geological and Atmospheric Science Department Iowa State University Ames, Iowa Institute for Science and Society Iowa State University 4 May 2004

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Outline  Evidence for global climate change  Future atmospheric carbon dioxide concentrations  Simulations of global climate and future climate change  Implications for stream flow and nutrient loss  International collaboration for understanding water and energy cycles  Summary

Carbon Dioxide and Temperature

2004

Carbon Dioxide and Temperature

Carbon Dioxide and Temperature Stabilization at 550 ppm

Carbon Dioxide and Temperature “Business as Usual” (fossil intensive) 2100

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Associated Climate Changes  Global sea-level has increased 1-2 mm/yr  Duration of ice cover of rivers and lakes decreased by 2 weeks in N. Hemisphere  Arctic ice has thinned substantially, decreased in extent by 10-15%  Reduced permafrost in polar, sub-polar, mountainous regions  Growing season lengthened by 1-4 days in N. Hemisphere  Retreat of continental glaciers on all continents  Poleward shift of animal and plant ranges  Snow cover decreased by 10%  Earlier flowering dates  Coral reef bleaching Source: Intergovernmental Panel on Climate Change, 2001 Report

Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

Source: Jerry Meehl, National Center for Atmospheric Research

Source: National Center for Atmospheric Research

Source: Intergovernmental Panel on Climate Change, 2001 Report

40% Probability 5% Probability Source: Intergovernmental Panel on Climate Change, 2001 Report

Climate Change Projected for 2100 Rapid Economic Growth Slower Economic Growth

IPCC Summary for Policy Makers  An increasing body of observations gives a collective picture of a warming world and other changes in the climate system  Emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate

IPCC Summary for Policy Makers, cont’d  Confidence in the ability of models to project future climate has increased  There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities

IPCC Summary for Policy Makers, cont’d  Confidence in the ability of models to project future climate has increased  There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities

IPCC Summary for Policy Makers, cont’d  Confidence in the ability of models to project future climate has increased  There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities

IPCC Summary for Policy Makers, cont’d  Anthropogenic climate change will persist for many centuries  Further action is required to address remaining gaps in information and understanding

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Climate Surprises  Breakdown of the ocean thermohaline circulation (Greenland melt water)  Breakoff of the West Antarctic Ice Sheet

Climate Cold Warm Ice Volume 0 Antarctica Greenland

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Regional Climate Change for the US Midwest  Observed and projected changes in climate  Impact on water quantity and water quality  Policy implications

For the Midwest  Warming will be greater for winter than summer  Warming will be greater at night than during the day  A 3 o F rise in summer daytime temperature triples the probability of a heat wave  Growing season will be longer (8-9 days longer now than in 1950)  More precipitation  Likely more soil moisture in summer  More rain will come in intense rainfall events  Higher stream flow, more flooding

Sub-Basins of the Upper Mississippi River Basin 119 sub-basins Outflow measured at Grafton, IL Approximately one observing station per sub-basin Approximately one model grid point per sub-basin

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Soil Water Assessment Tool (SWAT)  Long-term, continuous watershed simulation model (Arnold et al,1998)  Assesses impacts of climate and management on yields of water, sediment, and agricultural chemicals  Physically based, including hydrology, soil temperature, plant growth, nutrients, pesticides and land management  Daily time steps

SWAT Output with Various Sources of Climate Input

Validation of SWAT: Annual Stream Flow at Grafton, IL

Validation of SWAT: Monthly Stream Flow at Grafton, IL

RegCM2 Simulation Domain Red = global model grid point Green/blue = regional model grid points

Annual Stream Flow Simulated by SWAT Driven by the RegCM2 Regional Climate Model with NNR Lateral Boundary Conditions

Mean Monthly Precipitation Simulated by the RegCM2 Regional Climate Model with NNR Lateral Boundary Conditions

Seasonal Stream Flow Simulated by SWAT Driven by the RegCM2 Regional Climate Model with NNR Lateral Boundary Conditions

“Warming Hole”  T max (JJA) ˚C

Ten-Year Mean Precipitation Generated by the RegCM2 Regional Climate Model Driven with HadCM2 Global Model Results for the Contemporary and Future Scenario (2040s) Climate

Ten-Year Mean Monthly Stream Flow Generated by the RegCM2 Regional Climate Model Driven with HadCM2 Global Model Results for the Contemporary and Future Scenario (2040s) Climate

Comparison of Simulated Stream Flow under Climate Change with Various Model Biases

Relation of Runoff to Precipitation for Various Climates

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Regional Climate Modeling for Informing Policy on Water Quality  How does the combination of climate change and land use impact water quality?  Use nitrates and sediment as indicators  What alternative land management strategies will improve water quality?  What policies need to be implemented to achieve this water quality improvement?

Maquoketa Watershed

Scenario 1: all Agriculture Scenario 2: all Forest

Scenario 3: N. half Agric. and S. half Forest. Scenario 4: S. half Agric. and N. half Forest.

Scenario 5: Upper half Agric. and lower half Forest. Scenario 6: Lower half Agric. and upper half Forest.

Scenario 7: Main channel basins - Agric. Scenario 8: Main channel basins - Forest.

Scenario1995 (normal year)1993 (wet year)1988 (dry year) FlowSediment yieldNitrate Scenario Scenario Scenario Scenario Scenario Scenario Scenario Scenario Fractional changes in mean annual flow and yield under various scenarios normalized by the fractional change in area from all-agricultural for the scenario.

Scenario1995 (normal year)1993 (wet year)1988 (dry year) FlowSediment yieldNitrate Scenario Scenario Scenario Scenario Scenario Scenario Scenario Scenario Fractional changes in mean annual flow and yield under various scenarios normalized by the fractional change in area from all-agricultural for the scenario.

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Improving Regional Climate Models  Project to Intercompare Regional Climate Simulations  Transferability Working Group of GEWEX

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Project to Intercompare Regional Climate Simulations (PIRCS) PIRCS Mission To provide a common framework for evaluating strengths and weaknesses of regional climate models and their component procedures through systematic, comparative simulations PIRCS Co-Directors Ray Arritt Bill Gutowski Gene Takle

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS F Danish Met. Inst. (HIRHAM4; J.H. Christensen, O.B. Christensen) F Université du Québec à Montréal (D. Caya, S. Biner) F Scripps Institution of Oceanography (RSM; J. Roads, S. Chen) F NCEP (RSM; S.-Y. Hong) F NASA - Marshall (MM5/BATS; W. Lapenta) F CSIRO (DARLAM; J. McGregor, J. Katzfey) F Colorado State University (ClimRAMS; G. Liston) F Iowa State University (RegCM2; Z. Pan) F Iowa State University (MM5/LSM; D. Flory) F Univ. of Maryland / NASA-GSFC (GEOS; M. Fox-Rabinovitz) F SMHI / Rossby Centre (RCA; M. Rummukainen, C. Jones) F NOAA (RUC2; G. Grell) F ETH (D. Luethi) F Universidad Complutense Madrid (PROMES; M.Gaertner) F Université Catholique du Louvain (P. Marbaix) F Argnonne National Lab (MM5 V3; J. Taylor, J. Larson) F St. Louis University (Z. Pan) PIRCS Participating Groups

La Plata

Develop the ability to predict the variations of global and regional hydrological processes and water resources, and their response to environmental change. Foster the development of observing techniques, data management, and assimiliation systems suitable for operational application to long-range weather forecasts, hydrology, and climate predictions. Determine the hydrological cycle and energy fluxes by means of global measurements of observable atmospheric and surface properties. Model the global hydrological cycle and its impact on the atmosphere, oceans, and on the land surface. OBJECTIVES Global Energy and Water Cycle Experiment

Phase II Primary Science Questions Is the Water Cycle Accelerating? 1.Are the Earth’s Energy Budget and Water Cycle Changing? 3. Can We Predict these Changes on up to S - IA? 2. How do Processes Contribute to Feedback and Causes of Natural Variability? 4. What are the Impacts of these Changes on Water Resources? Updated GEWEX Science Questions :

Data Management Water and Energy Budget Studies Water Resource Applications Project Sources and Cycling of Water Extremes Predictability Transferability CEOP IAEA GAME

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Summary Regional climate models demonstrate sufficient skill to be useful for driving some climate impacts assessment models for the purpose of informing policy makers and decision-makers of vulnerabilities and opportunities associated with future climate change

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS For More Information  See my online Global Change course:  Contact me directly: