Clustering Lightning to Investigate Intensity Change and Convection Patterns in North Atlantic Tropical Cyclones

Lightning is often used as a proxy for deep convection in storm systems, and lightning data reveal important features within tropical cyclones. Particularly, as organized convection patterns – and, within those, Dvorak cloud patterns –are investigated, relationships between lightning occurrence and intensity changes arise. We use lightning data from the World Wide Lightning Location Network (WWLLN) and the Geostationary Lightning Mapper (GLM) to observe the spatial and temporal lightning distribution in North Atlantic tropical cyclones for the seasons of 2019 to 2022, for periods of intensification, weakening, and no intensity change. Additionally, lightning is clustered with the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) technique to visualize convection patterns and to track cluster counts during the evolution of tropical cyclones. Findings include the appearance of inner core lightning during weakening and sometimes intensification, as well as the presence of Dvorak patterns during various stages of intensification. WWLLN and GLM generally provide similar results, although detection efficiency of WWLLN is lower. We also present case studies, including hurricanes Dorian (2019) and Ian (2022) that underwent rapid intensification.