Magnetospheric Substorm: Earth's Magnetosphere Releasing Energy

To understand what a magnetospheric substorm is, it's important to know a little about the shape of Earth's magnetoshpere. There are magnetic field lines surrounding Earth, created by electric currents in Earth's liquid outer core. Without interference from solar winds the magnetoshpere would look like Image 1 below. But due to solar winds that blast against Earth's magnetic field, the shape of our magnetoshpere is more like a bullet shape, where the side facing the sun is compressed and the opposite side (the side not facing the sun) is stretched out and elongated (called the magnetic tail or 'magnetotail' ). The second image depicts the shape of our magnetosphere.

Magnetospheric substorm's are pretty cool. A magnetospheric substorm occurs when a disturbance in Earth's magnetosphere causes energy to be released from the magnetic tail. The top and bottom magentic lines in a portion of the magnetotail are squeezed until they reconnect, and this reconnection causes energy to be released. Magnetospheric substorm's occur very often - every few hours. When substorms occur they funnel solar particles into Earth's atmosphere which causes auroras to form, but only in the polar regions. The video below is a visualization that shows this process of energy releasing along Earth's magnetic field lines.

This is a cool artistic depiction of the magnetosphere being blasted and shaped by solar winds that are ejected from the Sun.

(Image credit: NASA)