خردطوفان

Also known as magnetospheric substorm, auroral substorm

thumb|right|A series of images made by ultraviolet light imager on the Polar (satellite)|Polar spacecraft showing the aurora and Earth's upper atmosphere. The glowing side is the atmosphere lit up by the Sun's light energy and the oval of light is the aurora. During a substorm the auroral oval brightens in a localized area and then suddenly breaks into many different forms that expand both toward Earth's pole and equator. This is exactly what Shun-ichi Akasofu (1964) drew in his auroral substorm illustration. thumb|Short video featuring commentary by David Sibeck, project scientist for the THE