Developing a geospatial framework for coupled large scale thermal comfort and air quality indices using high resolution gridded meteorological and station based observations

Current bioclimate and air quality indices provide insufficient information about the combined effect on human physiology in outdoor spaces. This work examined, large scale gridded meteorological observations, including air temperature, wind speed, solar radiation, and relative humidity, to derive Universal Thermal Climate Index (UTCI) at hourly intervals along with the air quality index (AQI) derived from Environmental Protection Agency (EPA) observation stations. UTCI and AQI were combined into a single framework using geospatial analytics and a newly developed lookup table approach. High risk areas for heat stress and poor air quality were identified using Moran's I and Getis-Ord GI* statistics. Moderate to strong heat stress was observed during the summer months of 2015-2019, with UTCI ranging from 26 degrees C to 38 degrees C. Coastal regions consistently experienced higher UTCI during noon due to higher humidity but the effect subsided with cooler air circulation from the ocean, especially in the morning and evening. Results also indicated the vulnerability of this region due to the combined impact of heat stress and poor air quality based on 95th percentile values. The final products from this analysis can provide valuable insights for urban planning and preventative measures to ensure improved public health in outdoor environments.