Effects of a lightning discharge detected by the DE 2 satellite over Hurricane Debbie

We report the satellite observation of a large, ∼40 mV m−1, transient electric field disturbance over Hurricane Debbie in September 1982. The event lasted less than a second and correlated closely with a burst of highly field‐aligned, upward moving electrons with nearly 1 keV of energy. The electric field event is viewed as a spheric disturbance from a lightning discharge in the active weather system located beneath the satellite. A spheric interpretation of the observed electric field transient is consistent with a subsequent observation of energetic electrons precipitating from the radiation belts. Measured quasi‐dc electric fields and cold plasma density variations are only roughly consistent with model predictions for ULF wave propagation from a storm system to the ionosphere. To understand this first observation of upward moving electrons in the ionosphere associated with a lightning event, we compare the several mechanisms for electron acceleration by electric fields with components (E∥) along the magnetic field. In our scenario, “runaway” electrons were accelerated in ∼1 ms by a downward directed E∥ pulse of ∼1 V m−1 magnitude. Such fields can result from rapidly exposed, negative space charges near the tops of clouds during positive cloud‐to‐ground discharges. High‐frequency Fourier components of the E∥ pulse must propagate through the low‐conducting nighttime atmosphere to the ionosphere with little dissipation.