Assessing the Impact of Post-Fire Land-Surface Changes on Weather Forecasting in Two Forested Areas

Wildfires have extensively burned areas worldwide, with significant impacts in various aspects of life. Among these, wildfires affect land-surface properties, such as vegetation nature and soil characteristics, from active burning to years and decades afterward. Despite this, the qualitative effects of post-wildfire conditions on short-term weather forecasting remain obscure. In this study, we investigated the impact of post-wildfire conditions on weather forecasting by considering post-wildfire land-surface conditions using the Weather Research and Forecasting (WRF) model in two burned forest areas. The changes in land-surface properties caused by wildfires were considered, including vegetation fraction, leaf area index, roughness length, emissivity, and soil hydraulic conductivity. The results show that post-wildfire land-surface properties have noticeable impacts on near-surface variables and atmospheric profiles. Over the study areas, the simulated near-surface air temperature could be approximately 1 K cooler and 0.75 g/kg moister if post-wildfire conditions are ignored, with impacts extending more than 3 km high in the vertical direction. This study also demonstrates that the effects of changes in land-surface properties over burned areas could extend to surrounding unburned areas.