24STUDENT Vigorous Self-Breeding of African Small Wildfires via Fire-Lightning Interaction in a Warming Climate

Forest wildfires, despite small burned areas (BAs), commonly have great combustion intensities (defined as fuel consumed per unit BA) to promote thunderstorms via fire heat. The associated lightning, in turn, ignites new fires. The extent to which the fire-lightning positive feedback exacerbates forest fires and lightning as climate warms in Africa, a hotspot of both wildfire and lightning, remains elusive. Here, we show that there are widespread intensifications of combustion-intense small wildfires, efficiently boosting thunderstorm lightning and new ignitions. Despite moisture constraints on fire spread in rainforests, lightning in fire-induced convection increases BAs by 25.50±5.57%with a disproportionately sharp surge of carbon emissions by 32.97±7.06% due to dense fuel loads. These findings highlight the vigorous self-breeding of African small forest wildfires as climate warms.