Quantitative Investigation of Lightning-Driven Coupling Across the Troposphere, Middle Atmosphere, and Ionosphere

This study presents a comprehensive quantitative analysis of lightning observations to investigate how deep convective systems evolve spatially and temporally and how they interact with the middle and upper atmosphere. The novelty lies in integrating lightning-source characterization, atmospheric gravity-wave (AGW) diagnostics, traveling ionospheric disturbance (TID) analysis, and complementary lower-ionospheric observations within a unified framework. The Boltek LD350 detector provides lightning location, occurrence, spatial concentration, and relative energy intensity. Gridded lightning data are used to determine event density, maximum energy-density regions, intensity-weighted centroids, and temporal migration. Representative events exhibit lightning energy densities of approximately 10²–10³ J km⁻², with the strongest cases reaching several 10³ J km⁻². Dual-frequency GNSS observations are used to derive vertical total electron content (VTEC), from which the slowly varying background is removed to obtain small-scale ΔVTEC fluctuations. Continuous wavelet transforms of detrended VTEC for individual satellite–receiver paths quantify transient TIDs through dominant periods, maximum spectral power, temporal evolution, and spatial coherence. Multi-PRN and ionospheric pierce-point comparisons distinguish propagating disturbances from local fluctuations. The strongest TID cases show wavelet spectral powers of approximately 0.2–7, while maximum ΔVTEC responses occur tens to several hundred kilometers from regions of maximum lightning energy density. We independently investigate AGW excitation using ECMWF and TIMED/SABER temperature profiles by separating background and perturbation temperatures and analyzing normalized temperature fluctuations, Brunt–Väisälä frequency, and gravity-wave potential energy. Enhanced lightning and convection are associated with stronger temperature perturbations and AGW signatures, followed by spatially displaced GNSS-TEC disturbances. Complementary VLF observations indicate an additional electromagnetic pathway involving lightning-generated radio emissions, lower-ionospheric conductivity perturbations, and possible lightning-induced electron precipitation. The results demonstrate concurrent dynamical and electromagnetic pathways for storm-driven energy transfer from the troposphere through the middle atmosphere to the ionosphere.