Global atmospheric electrical circuit Science. Global atmospheric electrical circuit The global atmospheric electrical circuit is the course of continuous movement of atmospheric electricity between the ionosphere and the Earth. Through solar radiation, thunderstorms, and the fair-weather condition, the atmosphere is subject to a continual and substantial electrical current. Principally, thunderstorms throughout the world carry "negative" charges to the earth, which is then discharged gradually through the air in fair weather. This atmospheric circuit is central to the study of atmospheric physics and meteorology. It is used in the prediction of thunderstorms, and was central to the understanding of electricity. In the past it has
Atmospheric duct bent by atmospheric refraction. In over-the-horizon radar, ducting causes part of the radiated and target-reflection energy of a radar system to be guided over distances far greater than the normal radar range. It also causes long distance propagation of radio signals in bands that would normally be limited to line of sight. Normally radio "ground waves" propagate along the surface as creeping waves. That is, they are only diffracted around the curvature of the earth. This is one reason that early long distance radio communication used long wavelengths. The best known exception is that HF (3–30 MHz.) waves are reflected