Spatiotemporal Analysis of United States Wet-Bulb Globe Temperature (WBGT) Extremes Derived from ERA5 Reanalysis Data

Keywords: extreme heat, wet bulb globe temperature
Abstract Type: Poster Abstract

Abstract

Wet-bulb globe temperature (WBGT) has emerged as a leading metric for characterizing the impact of warm, humid environmental conditions on human morbidity and mortality. WBGT is a linear combination of three factors: the air temperature, the natural wet-bulb temperature, and the globe temperature. The last term is measured using a hollow metal sphere painted black and fitted with an internal temperature sensor. Application of WBGT to understand historical variability in heat stress has been restricted by the lack of direct measurements of the natural wet-bulb temperature and the globe temperature. For this study, we have derived an hourly WBGT data set at 0.25 degree resolution based on application of a WBGT model to output from the ECMWF ERA5 reanalysis data set. Following derivation of the hourly product, the data are used to assess historical WBGT extremes over the period of 1961-2020. Historical analysis of extremes are conducted with a focus on spatial extent and duration of events characterized by high WBGT values.