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The outer boundary of a celestial body's magnetosphere.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


the border between a magnetic field and the surrounding plasma, specifically that between the earth's magnetic field and the sun's plasma
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(mægˈni təˌpɔz)

1. the boundary between the earth's magnetosphere and interplanetary space, ab. 40,000 mi. (65,000 km) above the earth.
2. a similar feature of another planet.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in periodicals archive ?
The view, which was detected as part of the scientists' work on the MMS mission, had enough resolution to reveal its differences from other reconnection regimes around the planet like the asymmetric process found in the magnetopause around Earth which is closer to the sun.
The paper, titled "New Results From Galileo's First Flyby of Ganymede: ReconnectionaDriven Flows at the LowaLatitude Magnetopause Boundary, Crossing the Cusp, and Icy Ionospheric Escape," appeared online in the journal Geophysical Research Letters.
The products can be used to evaluate the level of geomagnetic activity and the solar wind dynamic pressure, to estimate the magnetopause crossings and shocks, to provide input to the space weather forecasting model, to provide a database for improving knowledge of the magnetosphere and solar-terrestrial interactions, and last, but not least, to process the pitch-angle production after combination with the energetic electron data.
Along a radial cut of the plasma coming inward from the Sun near the dayside sub-solar point, the solar wind and magnetosheath flow is high-beta, the magnetopause and immediate (thin) plasma boundary provides a high to low beta transition, and immediately within the low-latitude boundary layer (within the outer magnetosphere) plasma is low-beta.
The position of the magnetosphere boundary (magnetopause) varies according to solar wind dynamic pressure, but resides on average at ~ 10 [R.sub.E] in the dayside and much farther in the nightside (here [R.sub.E] is the Earth's radius 6371.2 km).
Once it reaches the outer magnetosphere, the author says, the plasma can be lost to the solar wind, either crossing through the magnetopause or being swept down the magnetotail.
The IMF meets up with Earth's magnetic field at the magnetopause, and it's here that a storm's power is determined.
It has contributed to the understanding of mechanisms important for the identification of sources, transport, and losses of particles within the magnetosphere as well as in the vicinity of its boundary regions like the magnetopause and bow shock as well as in the geomagnetic tail.
In the study, a NASA satellite called IMAGE (Imager for Magnetopause to Aurora Global Exploration) observed two powerful proton auroras in the arctic portion of Earth's upper atmosphere, or ionosphere.
The magnetosphere's outer boundary is the magnetopause, a tear- shaped bubble marking the boundary between the region of influence of Earth's magnetic field and the region of influence of the Sun's magnetic field.
The researcher's statistical analysis showed that Kelvin-Helmholtz waves occur at the magnetopause about 19% of the time, which is "much more frequently than previously thought," notes Raeder.
Previous discoveries derived from Cluster measurements have shown that the magnetopause is commonly subject to Kelvin-Helmholtz waves.