Observation of Schumann Resonances in the Earth's Ionosphere: Implications for Thunderstorm and Lightning Monitoring from Orbit

The Communications/Navigation Outage Forecasting System (C/NOFS) satellite investigates the electrodynamics of the equatorial regions using a low inclination (13°) orbit with perigee and apogee of 401 and 867 km, respectively. The satellite is equipped with a three-axis double probe electric field detector that provides continuous DC and AC electric field measurements, and two optical sensors for lightning detection. Among the most intriguing data acquired thus far, the electric field probe on C/NOFS unexpectedly detected Schumann resonances with amplitude up to ~1 μVm-1Hz-1/2 in the nightside ionosphere. We address these findings in the context of thunderstorms effects in the middle and upper atmosphere, namely implications for the global electric circuit dynamics and low frequency wave propagation.