Observational Study and Numerical Prediction Experiments on Wet-Bulb Globe Temperature in Tajimi, Gifu Prefecture: Consideration of Uncertainty with a Physics Parameterization Scheme and Horizontal Resolution of the Weather Research and Forecasting Model

Abstract

As part of research on the actual conditions of the thermal environment surrounding the city of Tajimi, Gifu prefecture, and the city of Kasugai, Aichi prefecture, the surface air temperature and wet-bulb globe temperature (WBGT) were investigated by observation at these locations on clear-sky days in August 2010. Numerical prediction experiments on the WBGT were performed to confirm the utility of the Weather Research and Forecasting (WRF) model. Sensitivity experiments utilizing physics parameterization schemes and horizontal resolution of the WRF model were conducted to confirm the predicted WBGT. The results showed that the maximum sensitivity with the parameterization scheme was 8.4°C for the daytime average, and especially, the simple thermal diffusion surface (SLAB) scheme caused an overestimation of 6.8°C. On the other hand, the maximum sensitivity with horizontal resolution was 0.5°C, which is much less than that with the parameterization scheme.