Daily Peak Activity of the African Lightning Chimney Based on Meteosat Third Generation (MTG) Lightning Imager (LI), World Wide Lightning Location Network (WWLLN), and Schumann Resonance (SR) Observations

Abstract

Lightning activity is strongly concentrated in tropical continental “chimneys”, among which the African lightning chimney stands out as the most intense globally. However, until recently, the incomplete and spatially uneven detection efficiency of ground-based lightning networks, together with the limited spatio-temporal coverage of satellite observations, have constrained the quantitative characterization of African lightning activity, particularly on the daily timescales. Since July 2024, the Lightning Imager (LI) onboard the Meteosat Third Generation (MTG) satellite has provided the first continuous, high-temporal-resolution observations of lightning activity over Africa and Europe from geostationary orbit. In this paper, we examine, based on the first year of MTG LI observations, how consistently daily peak activity in the African lightning chimney is represented in different observational data sets. For this purpose, we use MTG LI group and flash data, together with World Wide Lightning Location Network (WWLLN) stroke observations and Schumann resonance (SR) measurements, and focus on two key parameters: the daily peak activity and its timing. We find that daily peak activity derived from MTG flashes shows a strong positive correlation with SR intensity (r = 0.749), while WWLLN stroke observations show much weaker correspondence. The timing of the daily peak is broadly consistent across the data sets, with the best agreement observed between MTG flashes and SR intensity. For all data sets, daily peak activity is strongly correlated with total daily activity. The strong correspondence between MTG flashes and SR intensity supports the use of both data sets in characterizing the daily activity of the African lightning chimney.