Manifestations of global disturbances of the geomagnetic field in dynamics of thunderstorms

Using the method of diagnosing the electrical state of a thunderstorm atmosphere by variations of the secondary particles of cosmic rays recorded by the Carpet air shower array of the Baksan Neutrino Observatory (North Caucasus), the phenomenon of the mutual influence of a magnetic storm and thunderstorm activity was discovered. It has been established that during magnetic substorms of low power, at the preliminary stage and at the beginning of the development phase, penetration of magnetospheric–ionospheric disturbances at mid latitudes (∼400 N) above lightning centers is possible. This effect manifests itself in the form of a diffuse glow of the aurora type with a brightness of ∼3 ·10-4 cd·m-² and local disturbances of the electric field with a characteristic potential difference in the troposphere of order of \pm 100 MV. A local magnetic disturbance (∼ 1 nT) was recorded, corresponding to the appearance of a local vertical current in the atmosphere, whose maximum coincided with the beginning of the expansion phase of substorm nucleation.