The Cluster spacecrafts' view of the motion of the high-latitude magnetopause
File(s)
Published version
Author(s)
Grimmich, Niklas
Plaschke, Ferdinand
Grison, Benjamin
Prencipe, Fabio
Escoubet, Christophe Philippe
Type
Journal Article
Abstract
The magnetopause is the boundary between the interplanetary magnetic field and the terrestrial magnetic field. It is influenced by different solar-wind conditions, which lead to a change in the shape and location of the magnetopause. The interaction between the solar wind and the magnetosphere can be studied from in situ spacecraft observations. Many studies focus on the equatorial plane as this is where recent spacecraft constellations such as THEMIS or MMS operate. However, to fully capture the interaction, it is important to study the high-latitude regions as well. Since the Cluster spacecraft operate in a highly elliptical polar orbit, the spacecraft often pass through the magnetopause at high latitudes. This allows us to collect a dataset of high-latitude magnetopause crossings and to study magnetopause motion in this region, as well as deviations from established magnetopause models. We use multi-spacecraft analysis tools to investigate the direction of the magnetopause motion in the high latitudes and to compare the occurrence of crossings at different locations with the result in the equatorial plane. We find that the high-latitude magnetopause motion is generally consistent with previously reported values and seems to be more often associated with a closed magnetopause boundary. We show that, on average, the magnetopause moves faster inwards than outwards. Furthermore, the occurrence of magnetopause positions beyond those predicted by the Shue et al. (1998) model at high latitudes is found to be caused by the solar-wind parameters that are similar to those in the equatorial plane. Finally, we highlight the importance of the dipole tilt angle at high latitudes. Our results may be useful for the interpretation of plasma measurements from the upcoming SMILE mission (Branduardi-Raymont et al., 2018) as this spacecraft will also fly frequently through the high-latitude magnetopause.
Date Issued
2024-09-12
Date Acceptance
2024-07-29
Citation
Annales Geophysicae: atmospheres, hydrospheres and space sciences, 2024, 42 (2), pp.371-394
ISSN
0992-7689
Publisher
Copernicus Publications
Start Page
371
End Page
394
Journal / Book Title
Annales Geophysicae: atmospheres, hydrospheres and space sciences
Volume
42
Issue
2
Copyright Statement
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
License URL
Identifier
http://dx.doi.org/10.5194/angeo-42-371-2024
Publication Status
Published
Date Publish Online
2024-09-12