Disturbances in the Ionosphere Registered by Demeter and Swarm Satellites during Geomagnetic Storms and Thunderstorms – Similarities and Differences

Disturbances in the ionospheric plasma due to geomagnetic storms and thunderstorms recorded by the DEMETER and Swarm satellites are presented. Lightning and, in particular, transient luminous events (sprites, jets, elves and halos) are associated with the electromagnetic links and interactions between the atmosphere, ionosphere and magnetosphere and with intense thunderstorm activity. DEMETER has clearly shown that thunderstorms and sprites can affect the ionosphere even at its orbital altitude (680 km). Additional information on ionospheric disturbances comes from data collected by the Swarm satellites. The Swarm constellation consists of three identical satellites. Two of them operate in circular polar orbits with an initial altitude of 460 km, while the third satellite has a circular orbit but an altitude of 530 km. The orbits of the first two satellites are almost in the same plane, but the third satellite is almost perpendicular to the first two. The payload, which includes a vector field magnetometer, an absolute scalar magnetometer and an electric field instrument, will make it possible to study the effects of thunderstorms on the ionosphere. Registrations of ionospheric disturbances collected by DEMETER and Swarm during selected strong geomagnetic storms and thunderstorms over Poland and Central Africa are presented, and the similarities and differences are discussed.