The importance of lightning has long been recognized from the point of view of climate-related
phenomena. However, the detailed investigation of lightning on global scales is currently hindered by the
incomplete and spatially uneven detection efficiency of ground-based global lightning detection networks
and by the restricted spatio-temporal coverage of satellite observations. We are developing different methods
for investigating global lightning activity based on Schumann resonance (SR) measurements. SRs are
global electromagnetic resonances of the Earth-ionosphere cavity maintained by the vertical component of
lightning. Since charge separation in thunderstorms is gravity-driven, charge is typically separated vertically
in thunderclouds, so every lightning flash contributes to the measured SR field. This circumstance makes
SR measurements very suitable for climate-related investigations. In this study, 19 days of global lightning
activity in January 2019 are analyzed based on SR intensity records from 18 SR stations and the results are
compared with independent lightning observations provided by ground-based (WWLLN, GLD360, and
ENTLN) and satellite-based (GLM, LIS/OTD) global lightning detection. Daily average SR intensity records
from different stations exhibit strong similarity in the investigated time interval. The inferred intensity of global
lightning activity varies by a factor of 2–3 on the time scale of 3–5 days which we attribute to continental-scale
temperature changes related to cold air outbreaks from polar regions. While our results demonstrate that the SR
phenomenon is a powerful tool to investigate global lightning, it is also clear that currently available technology
limits the detailed quantitative evaluation of lightning activity on continental scales.
