Cumulative Effects of Lightning Electromagnetic Pulses on the Lower Ionosphere

Lightning strokes emit electromagnetic pulses that interact with the lower ionosphere. One manifestation of this interaction are elves: Ring‐shaped light emissions from altitudes around 85 km above ground produced by active thunderstorms. Perturbations to the conductivity at those altitudes relax with time‐scales longer than 10 min and therefore one strong pulse may affect the features of subsequent pulses. Here we develop a simplified model to investigate this possibility. We apply this model to thunderstorms with a copious production of high‐peak‐current strokes, finding changes in the altitude profile of light emissions for elves at different stages of the thunderstorm evolution.