Currents in a magnetosphere are like arteries in the human body. They are the manifestation of particles being carried from one region to another. Moreover, they are an integral part of what creates the magnetosphere itself.
The presence of magnetic fields leads to the existence of currents, and the presence of currents leads to magnetic fields. The two are intricately intertwined. Thus in a planetary magnetosphere, the bending and twisting magnetic fields lead to a dist
inct set of current systems.
There are three main current systems in a magnetosphere.
- Chapman-Ferraro currents (in green)
- cross-tail currents (in blue)
- Field-Aligned currents (FAC's) in red)
The Chapman-Ferraro currents enclose and confine the global magnetosphere. They are found in the vicinity of the magnetopause.
Cross-tail currents pass through the center of the magnetotail, and cause that region to be known as the "current sheet".
Field-Aligned currents are transient currents which short-circuit through a planets ionosphere (which is a conducting medium), and which are part of generating the aurora.
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