The Effects of Biomass Burning Aerosols from Central America on the Severity of Tornado Outbreaks in the Southeast United States

Due to the increase of population in our nation’s cities, it is becoming increasingly paramount for meteorologists to accurately predict tornado outbreaks. Prediction accuracy can be improved by understanding the fundamental physical processes driving these outbreaks. Among these important processes is the role of aerosols in cloud formation, specifically the severity and intensity of tornado outbreaks, and individual tornadoes, respectively. This research explores the relationship between biomass burning aerosols generated in Central America and the severity of tornado outbreaks in the southeastern United States, with respect to their role as cloud condensation nuclei (CCN). Data is comprised of Moderate Resolution Imaging Spectroradiometer (MODIS) Thermal Anomalies, MODIS 8’s Aerosol Optical Depth (AOD), Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) Trajectories, and NOAA’s Storm Prediction Center (SPC) tornado reports covering 108 days or “events”, encompassing 16 Spring seasons (2001-2016). Using the southeastern United States as a reference region, the number of tornado reports is cross referenced with the MODIS 8's AOD thickness per event. Additionally, HYSPLIT trajectories and thermal anomalies are cross referenced with tornado reports across Central America and the Gulf of Mexico. These cross references are then split into two groups consisting of high and low probability events. The antecedent cross-references are confirmed through utilization of linear regression, allowing for relationships to be drawn between AOD and southeast U.S. tornado outbreaks. Through this analysis, it is determined that a considerable connection exists between aerosol production, via biomass burning across Central America, and the increase in tornado outbreak severity and tornado intensity across the southeastern United States.