Identifying Dust Events lofted from Burn Scars using Dust RGB satellite imagery

Blowing dust, often overlooked in operational meteorology, adversely affects human health, transportation, and agriculture. Past research has identified critical forecasting criteria for blowing dust in at-risk areas, such as arid climates. Research has also shown that over half of wildfires were followed by dust events. As the climate changes and wildfires become more frequent, the mechanisms of post-wildfire burn scar contributions to dust events become pertinent. The goal of this project was to identify dust events lofted from a burn scar near Hastings, Nebraska, and evaluate the ability of satellite tools (e.g., Dust RGB, satellite soil moisture, and green vegetation fraction) to identify these events. Our research aims to identify critical soil characteristics and meteorological conditions that lead to blowing dust from post-fire burn scars. Our project focused on a burn scar in the Hastings, Nebraska, National Weather Service (NWS) county warning area which caused frequent dust events. This particular scar originated from a wildfire on October 23rd, 2022, in Nuckolls County. The fire burned over 10,000 acres and left behind a 7x3 mile scar, which remained visible on satellite imagery for over six months following the wildfire. The research strategy to find dust events from the scar began with the NWS, Hastings area forecast discussions. Discussions insinuating the potential for blowing dust or surface observation reports were used to narrow down dates and times that blowing dust may have been present. Then the Dust RGB was analyzed and three dust cases were subsequently identified, each occurring at a different stage of the burn scar’s healing process. In order to analyze the meteorological setup and soil conditions of each dust case, we compared them to accepted critical criteria for dust lofting. We determined that these three dust cases met all accepted criteria for dust lofting. Further investigation is needed to determine the critical soil moisture thresholds for a burn scar dust-lofting event and how the age, severity, and recovery of the burn scar contribute to the occurrence/strength of a dust event. Future work includes the identification of additional burn scar dust events and analysis to understand the processes that initiate these events.