A High Resolution (4 km) WRF Regional Climate Simulation for Indiana Climate Change Impact Assessment: Model Evaluation and Statistical Bias Correction

In an effort to assess the impacts of climate change across the state of Indiana, the Weather Research and Forecasting (WRF) model (version 3.8.1) was used to dynamically downscale the National Center for Atmospheric Research (NCAR) Community Earth System Model (CESM) Global Bias-corrected Coupled Model Intercomparison Project Phase 5 (CMIP5) data. The WRF regional climate simulations were run for 30 years in the historical period (1976-2005) and for 95 years in 21st century period (2006-2100), at an hourly output frequency. Representative Concentration Pathway (RCP) future scenario RCP8.5 was used for the 21st century simulations. The WRF simulations were carried out using the Smart Management of WRF Simulation (SMWRFS) system at Purdue University. The performance of the WRF simulations were evaluated by comparing results with the National Centers for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR) data for 26 years of the historical period (1980-2005) and weather station data. The WRF simulations yielded considerable warm and dry biases during the summer season and a slight cold bias during the winter season. Results during the spring and fall seasons were generally comparable. Vertical profiles of temperature, specific humidity, pressure height, and wind were closely simulated to those of the NARR while the warm and dry biases remain visible in the lower atmosphere. An empirical distribution correction method was applied to correct biases in 2 m temperature both in historical and future periods. Further details about the model configuration and set up, bias correction method, results, and future research directions will be discussed.