Physics and Dynamics of Earth's Geopauses
Abstract
The geopause is the boundary separating solar wind plasma from ionospheric plasma. This is not a single boundary but rather a family of them, with the specific location depending on the parameter used to define it, like plasma pressure, number density, or mass density. The location of these geopause boundaries are presented and discussed, including their dynamics during interplanetary magnetic field reversals. Their relation to the magnetopause is shown and discussed too; a relative location that changes dramatically depending on IMF and ionospheric outflow conditions. In addition, the dominant physical processes on or near these boundaries is presented and discussed, showing that important transitions occur as the plasma source changes between solar wind and ionospheric origin. This study simulates the Earth's magnetosphere by using the multifluid capabilities of the Block Adaptive Tree Solar wind Roe-type Upwind Scheme magnetohydrodynamics model within the Space Weather Modeling Framework. The magnetopause was smaller than the other geopauses during southward IMF but for northward IMF, the magnetopause was the largest structure in comparison with the plasma based geopauses. Our results indicate that no single boundary surface is particularly more important than others because they all have some relationship to physical process changes, which are explored and discussed.
- Publication:
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43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E1077L