Downscaled Climate Change Projection for the Department of Energy s Savannah River Site Carolinas Climate Resilience Conference Charlotte, North Carolina: April 29 th, 2014 David Werth Atmospheric Technologies Group Savannah River National Laboratory
Savannah River National Laboratory Atmospheric Technologies Group Perform meteorological monitoring and dispersion modeling in support of emergency operations. Provide forecasting for site operations and USFS controlled burns. Conduct trace gas and other long-range transport studies. Use statistically-downscaled global climate model (GCM) output to produce a long-term climate forecast.
Savannah River National Laboratory Atmospheric Technologies Group Perform meteorological monitoring and dispersion modeling in support of emergency operations. Provide forecasting for site operations and USFS controlled burns. Conduct trace gas and other long-range transport studies. Use statistically-downscaled global climate model (GCM) output to produce a long-term climate forecast.
GCMs are largely unable to predict climate variables at the small-scale. Monthly Mean July Temperatures at Dalton, GA
Statistical Downscaling Compare the GCM to the observations for the past. Calculate a correction to fix the GCM, then apply the same correction to the future GCM data. What information can we assume the GCM is predicting correctly, and what GCM information should be replaced?
Monthly Mean July Temperatures at Dalton, GA
Monthly Mean July Temperatures at Dalton, GA
Bias
Mean + 1.5⁰
Downscaling Process: Quantile Mapping Each GCM value is mapped to the observed value with the same likelihood of occurring. The mapping function is then used with the predicted future GCM data to get the downscaled forecast. Assumes that the change in the GCM distribution from the present to the future is correct.
Ranked Monthly Mean July Temperatures at Dalton, GA
Ranked Monthly Mean July Temperatures at Dalton, GA
Future Monthly Mean July Temperatures at Dalton, GA 2040
Future Monthly Mean July Temperatures at Dalton, GA 2040 2041
Future Monthly Mean July Temperatures at Dalton, GA
Future Monthly Mean July Temperatures at Dalton, GA
Model Organization Number of Realizations CCSM4 NCAR 3 Can-ESM2 Environment Canada 4 GISS-E2-H Four global climate models Ensemble of 14 Members Goddard Inst. Space Studies MPI-ESM-LR Max Planck Inst. 3 4
Two Future Scenarios Representative Concentration Pathways (RCPs) Greenhouse gas concentration trajectories adopted by the IPCC for its fifth Assessment Report (AR5). RCP4.5 = +4.5 W/m 2 in 2100 RCP8.5 = +8.5 W/m 2 in 2100
Observed and Model Monthly Mean Data at Savannah River Site (SRS) Input = Future GCM value at SRS
Observed and Model Monthly Mean Data at Savannah River Site (SRS) Output = Downscaled future value at SRS Input = Future GCM value at SRS
Temperature Annual Cycle, 2040-2049
Ensemble Minimum and Maximum
Daily Maximum Temperature, 2040-2049 RCP4.5
Daily Maximum Temperature, 2040-2049 RCP8.5
Precipitation, 2040-2049 RCP4.5
Precipitation, 2040-2049 RCP8.5
GCM (2040-2049) OBS(1970-2012)
GCM (2040-2049) OBS(1970-2012)
Fraction of days from 2040-2049 with Daily Maximum Temperature above 95 th Percentile
Fraction of Months from 2040-2049 with Precipitation above the 95 th Percentile
Future Work Use downscaled temperature and precipitation data as input to a model of surface hydrology, to predict future streamflow at SRS. Precipitation Evaporation Surface Runoff Infiltration Streamflow
Future Work Apply the data to models of onsite energy and water use. Precipitation Evaporation Surface Runoff Infiltration Streamflow
Future Work Pass temperature, precipitation, wind and humidity data to researchers at the U.S. Forest Service, for use in long-term prediction of fire susceptibility. Apply the data to ecological population models.
Future Work Q: If precipitation and temperature are downscaled separately, will this produce an inconsistent climate forecast?