Multi-Spacecraft Analysis of Dipolarization Events With Inductive, Radial Electric Fields in the Inner MagnetosphereShow others and affiliations
2025 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 130, no 6, article id e2025JA033807Article in journal (Refereed) Published
Abstract [en]
Dipolarization events with inductive, radial electric fields are investigated with multi-spacecraft analysis techniques. Observations by Magnetospheric Multiscale with separations around ion scales are used to study spatial and temporal variations of these events in the inner magnetosphere. JxB $J\times B$ force, magnetic pressure force, and tension force are compared based on the Taylor expansion method, which includes the curlometer technique. The magnetic pressure force, possibly related to energetic particles and magnetic flux transported from the magnetotail, tends to contribute to the JxB force for the background components near the equator, while the tension force, related to Alfv & eacute;n waves, contributes to the fluctuating components or outside the equator. The scale length is thousands of km for the background components, probably related to meso-scale structures, while that length is tens to a thousand km for fluctuating components. The small-scale fluctuations would be related to particle acceleration. The fluctuations are inferred to be Alfv & eacute;n waves with quasi-perpendicular propagation directions and with finite temperature or kinetic effects. These fluctuations could be intermittent and not self-similar between different inter-spacecraft distances. Some energy transfer from fluctuations to particles would occur.
Place, publisher, year, edition, pages
American Geophysical Union (AGU) , 2025. Vol. 130, no 6, article id e2025JA033807
Keywords [en]
dipolarization, inner magnetosphere
National Category
Fusion, Plasma and Space Physics
Identifiers
URN: urn:nbn:se:kth:diva-369287DOI: 10.1029/2025JA033807ISI: 001510894400001OAI: oai:DiVA.org:kth-369287DiVA, id: diva2:1999696
Note
QC 20250922
2025-09-222025-09-222025-09-22Bibliographically approved