Global atmospheric electrical circuit

[2] The basic concept of a global circuit is that through the balance of thunderstorms and fair weather, the atmosphere is subject to a continual and substantial electrical current.

Principally, thunderstorms throughout the world carry negative charges to the ground, which is then discharged gradually through the air away from the storms, in conditions that are referred to as "fair weather".

[3] The global electrical circuit is also relevant to the study of human health and air pollution, due to the interaction of ions and aerosols.

Important work was done by the research vessel Carnegie, which produced standardised measurements around the world's oceans (where the air is relatively clean).

Thunderstorms generate an electrical potential difference between the Earth's surface and the ionosphere, mainly by means of lightning returning current to ground.

Consequently, there is always a small current of approximately 2pA per square metre transporting charged particles in the form of atmospheric ions between the ionosphere and the surface.