Exploring the Relationship between Continuing Current in Lightning and Lightning-Initiated Wildfires using the Geostationary Lightning Mapper

The current in a lightning stroke will typically flow for on the order of a millisecond. Occasionally, the current can last for tens to hundreds of milliseconds, known as continuing current (CC) lightning. Since the current flow is accompanied by continuous optical emission, space-based optical observations in lightning, such as those collected by the Geostationary Lightning Mapper (GLM), provide an ideal way to detect CC lightning. A logistic regression model is used to quantify the probability a particular set of GLM attributes correspond to CC lightning. A climatology of GLM flashes that are characterized as CC lightning in 2018 will be highlighted.

Since the resulting uninterrupted charge flow associated with cloud-to-ground strokes with CC is believed to be related to wildfire initiation, the model can be used to probabilistically detect potential lightning-initiated wildfire locations and times. The Advanced Baseline Imager (ABI) Fire/Hot Spot Characterization product is used to detect wildfires, and GLM flashes are matched to the observed wildfires by applying specific spatial and temporal constraints. The matched GLM flashes are ingested into the model, and the average temporal length between the occurrence of GLM-identified CC lightning and resulting ABI fire/hot spot pixels is identified. Incorporating various satellite data to further refine the probability of an ignition, such as precipitation presence and atmospheric conditions at the time of a stroke, will also be discussed.