Estimating heat-related exposures and urban heat island impacts: A case study for the 2012 Chicago heatwave

An extreme HW event occurred in 2012 summer that caused temperatures of more than 40 degrees C in Chicago, Illinois, USA, which is a highly urbanized city impacted by UHIs. In this study, multiple numerical models, including the High Resolution Land Data Assimilation System (HRLDAS) and Weather Research and Forecasting (WRF) model, were used to simulate the HW and UHI, and their performance was evaluated.

In addition, sensitivity testing of three different WRF configurations was done to determine the impact of increasing model complexity in simulating urban meteorology. Model performances were evaluated based on the statistical performance metrics, the application of a multi-layer urban canopy model (MLUCM) helps WRF to provide the best performance in this study. HW caused rural temperatures to increase by similar to 4 degrees C, whereas urban Chicago had lower magnitude increases from the HW (similar to 2-3 degrees C increases).