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  • Observation of O+ Characteristics During the Terrestrial Alfvén Wing State Induced by the April 2023 Coronal Mass Ejection
Title: Observation of O+ Characteristics During the Terrestrial Alfvén Wing State Induced by the April 2023 Coronal Mass Ejection
Abstract We report Magnetospheric Multiscale observations of oxygen ions (O+) during a coronal mass ejection (CME) in April 2023 when the solar wind was sub‐Alfvénic and Alfvén wings formed. For the first time, O+ characteristics are studied at the contact region between the unshocked solar wind and the magnetosphere. The O+ ions show energies between 100s eV and ∼30 keV. The possible sources are the ring current, the warm plasma cloak, and the ionosphere. The O+ ions exhibit bi‐directional streaming along newly‐formed closed field lines (CFLs), and dominantly anti‐parallel on earlier‐formed CFLs. Escaping O+ ions in the unshocked solar wind are observed. During the recovery phase, the O+ pitch‐angle distribution associated with flux tubes shows dispersion, indicating potential loss to the solar wind. Our results show escaping as well as trapped O+ ions in the region where a magnetic cloud, an Alfvén wing, and magnetospheric field lines are mixed.  more » « less
Award ID(s):
2247718
PAR ID:
10632312
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ;
Publisher / Repository:
American Geophysical Union (AGU) and Wiley-Blackwell
Date Published:
Journal Name:
Journal of Geophysical Research: Space Physics
Volume:
130
Issue:
4
ISSN:
2169-9380
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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