A Birkeland current is a narrow and powerful electric current that flows along magnetic field lines in the Earth’s ionosphere, connecting the polar regions to the magnetosphere. These currents were first theorized by Norwegian physicist Kristian Birkeland in the early 20th century, and they are named in his honor.
Birkeland currents are caused by the interaction between the solar wind and the Earth’s magnetic field. When the solar wind particles, which are charged particles, collide with the Earth’s magnetic field, they can be deflected and trapped along the field lines, creating a current. The currents flow from the polar regions towards the equator and can reach up to 10^6 amperes.
Birkeland currents are responsible for many auroral phenomena, including the auroral oval, which is a ring-shaped region around the magnetic poles where the aurora borealis and aurora australis occur. The currents also play a significant role in space weather, affecting the Earth’s ionosphere and the performance of communication and navigation systems.
Birkeland currents have also been observed on other planets with magnetic fields, such as Jupiter and Saturn. The study of these currents is an active area of research in space physics and is important for understanding the complex interactions between the solar wind, magnetic fields, and plasma in the solar system. Read more about Admission Management.