An Analysis of Wet Bulb Globe Temperature Estimation Methods and Microclimate Heat Variability in Columbia, South Carolina

Extreme heat is the leading cause of weather-related deaths in the United States and poses major health risks in the wake of rising global average temperatures. Wet bulb globe temperature (WBGT) is a holistic measure of human heat stress, but is not feasible to implement in most settings because the equipment is expensive and troublesome to operate. This research evaluates the performance of WBGT estimation methods using more standard meteorological variables, measured in-situ and a local National Weather Service Automated Surface Observing Station, and examines how WBGT and its components vary across two distinct microclimates in Columbia, SC. Results indicate that the Stull and Black Globe Regression (BGR) method may be a reasonable proxy for WBGT, particularly when a localized data source is available, but this method likely underestimates heat risk. Alternatively, the Australian Bureau of Meteorology (ABM) method tends to overpredict WBGT but is the most convenient and accessible monitoring method because its only data inputs, temperature and relative humidity, are more readily available. Results also demonstrate meaningful differences in heat characteristics, such as temperature, humidity, and solar radiation, observed on a brick and a grass measurement site. These differences shed light on diurnal fluctuations in heat characteristics including elevated warming over the brick surface at nighttime, and higher moisture levels over the grass site leading to more oppressive daytime heat