Douglas Harper's Etymology Dictionary
Wiktionary
n. the boundary between the Earth's magnetosphere and the sun's plasma
Wikipedia
The magnetopause is the abrupt boundary between a magnetosphere and the surrounding plasma. For planetary science, the magnetopause is the boundary between the planet’s magnetic field and the solar wind. The location of the magnetopause is determined by the balance between the pressure of the dynamic planetary magnetic field and the dynamic pressure of the solar wind. As the solar wind pressure increases and decreases, the magnetopause moves inward and outward in response. Waves (ripples and flapping motion) along the magnetopause move in the direction of the solar wind flow in response to small scale variations in the solar wind pressure and to Kelvin-Helmholtz instability.
The solar wind is supersonic and passes through a bow shock where the direction of flow is changed so that most of the solar wind plasma is deflected to either side of the magnetopause, much like water is deflected before the bow of a ship. The zone of shocked solar wind plasma is the magnetosheath. At Earth and all the other planets with intrinsic magnetic fields, some solar wind plasma succeeds in entering and becoming trapped within the magnetosphere. At Earth, the solar wind plasma which enters the magnetosphere forms the plasma sheet. The amount of solar wind plasma and energy that enters the magnetosphere is regulated by the orientation of the interplanetary magnetic field, which is embedded in the solar wind.
The Sun and other stars with magnetic fields and stellar winds have a solar magnetopause or heliopause where the stellar environment is bounded by the interstellar environment.
Usage examples of "magnetopause".
I crossed the magnetopause, to become truly the first voyager in interstellar space .
Far beyond Jupiter and its moons, beyond the magnetopause, Mahnmut could sense the bow shock turbulence crashing like great white waves on a hidden reef, could hear the upstream Langmuir waves singing in the magnetic darkness past that reef, and could pick out the ion acoustic waves crackling after their long voyage uphill from the sun.
The next two factors, the magnetopause and the magnetotail, are created by the interaction of the Earth's magnetic field with the solar wind, a continual stream of particles outward bound from our hyperactive sun.
The blasters would be especially hard to aim in the magnetopause of Hesprid or the moons-at the edge of their magnetic fields-where the flow of the solar wind was turbulent and unpredictable.
The magnetopause is the 'bow wave' of the Earth's magnetic field as it heads into the solar wind.