Search results
Results from the WOW.Com Content Network
Schematic of the Birkeland or Field-Aligned Currents and the ionospheric current systems they connect to, Pedersen and Hall currents. [1]A Birkeland current (also known as field-aligned current, FAC) is a set of electrical currents that flow along geomagnetic field lines connecting the Earth's magnetosphere to the Earth's high latitude ionosphere.
In the height region between about 85 and 200 km altitude on Earth, the ionospheric plasma is electrically conducting. Atmospheric tidal winds due to differential solar heating or due to gravitational lunar forcing move the ionospheric plasma against the geomagnetic field lines thus generating electric fields and currents just like a dynamo coil moving against magnetic field lines.
Researchers have developed global models using MHD to simulate phenomena within Earth's magnetosphere, such as the location of Earth's magnetopause [24] (the boundary between the Earth's magnetic field and the solar wind), the formation of the ring current, auroral electrojets, [25] and geomagnetically induced currents.
The ring current system consists of a band, at a distance of 3 to 8 R E, [1] which lies in the equatorial plane and circulates clockwise around the Earth (when viewed from the north). The particles of this region produce a magnetic field in opposition to the Earth's magnetic field and so an Earthly observer would observe a decrease in the ...
This orbit enables observations of the magnetosphere’s response to varying solar wind conditions from the full range of vantage points over time scales encompassing all space weather phenomena. Furthermore, this orbit allows scientific return 100% of the time from at least a single instrument and up to 83% of the time from all instruments ...
MMS mission overview video Visualization of the spacecraft orbit transition. The MMS mission consists of four spacecraft. Each has a launch mass of 1,360 kg (3,000 lb). [6] In their stowed launch configuration, each are approximately 3.5 by 1.2 m (11.5 by 3.9 ft), and when stacked together they have a total height of 4.9 m (16 ft). [6]
Magnetic reconnection is a breakdown of "ideal-magnetohydrodynamics" and so of "Alfvén's theorem" (also called the "frozen-in flux theorem") which applies to large-scale regions of a highly-conducting magnetoplasma, for which the Magnetic Reynolds Number is very large: this makes the convective term in the induction equation dominate in such regions.
The plasmasphere, or inner magnetosphere, is a region of the Earth's magnetosphere consisting of low-energy (cool) plasma. It is located above the ionosphere . The outer boundary of the plasmasphere is known as the plasmapause , which is defined by an order of magnitude drop in plasma density.