Birkeland current
Автор:
Jesse Russell,Ronald Cohn, 103 стр., издатель:
"Книга по Требованию", ISBN:
978-5-5084-9096-6
High Quality Content by WIKIPEDIA articles! A Birkeland current is a set of currents which flow along geomagnetic field lines connecting the Earth’s magnetosphere to the Earth's high latitude ionosphere. Lately, the term Birkeland currents has been expanded by some authors to include magnetic field aligned currents in space plasmas in general. In the Earth’s magnetosphere, the currents are driven by the solar wind and interplanetary magnetic field and by bulk motions of plasma through the magnetosphere (convection which is indirectly driven by the interplanetary environment). The strength of the Birkeland currents changes with activity in the magnetosphere (e.g. during substorms). Small scale variations in the upward current sheets (downward flowing electrons) accelerate magnetospheric electrons which, when they reach the upper atmosphere, create the Aurora Borealis and Australis. In the high latitude ionosphere (or auroral zones), the Birkeland currents close through the region of...