Magnetic Reconnection Within the Boundary Layer of a Magnetic Cloud in the Solar Wind

Autor(en)
Zoltán Vörös, Ali Varsani, Emiliya Yordanova, Yury Sasunov, Owen W. Roberts, Rumi Nakamura, Yashuhito Narita
Abstrakt

The twisted local magnetic field at the front or rear regions of the magnetic clouds (MCs) associated with interplanetary coronal mass ejections (ICMEs) is often nearly opposite to the direction of the ambient interplanetary magnetic field. There is also observational evidence for magnetic reconnection (MR) outflows occurring within the boundary layers of MCs. In this study, a MR event located at the western flank of the MC occurring on October 3, 2000 is studied in detail. Both the large-scale geometry of the helical MC and the MR outflow structure are scrutinized in a detailed multipoint study. The ICME sheath is of hybrid propagation-expansion type. Here, the freshly reconnected open field lines are expected to slip slowly over the MC resulting in plasma mixing at the same time. As for MR, the current sheet geometry and the vertical motion of the outflow channel between ACE-Geotail-WIND spacecraft were carefully studied and tested. The main findings on MR include (a) first-time observation of non-Petschek-type slow-shock-like discontinuities in the inflow regions; (b) observation of turbulent Hall magnetic field associated with a Lorentz-force-deflected electron jet; (c) acceleration of protons by reconnection electric field and their back-scatter from the slow-shock-like discontinuity; (d) observation of relativistic electron near the MC inflow boundary/separatrix; these electron populations can presumably appear as a result of nonadiabatic acceleration, gradient B drift, and via acceleration in the electrostatic potential well associated with the Hall current system; and (e) observation of Doppler-shifted ion-acoustic and Langmuir waves in the MC inflow region.

Organisation(en)
Institut für Astrophysik
Externe Organisation(en)
Österreichische Akademie der Wissenschaften (ÖAW), MTA Társadalomtudományi Kutatóközpont, Swedish Institute of Space Physics, Lomonosov Moscow State University (MSU)
Journal
Journal of Geophysical Research: Space Physics
Band
126
Anzahl der Seiten
33
ISSN
2169-9380
DOI
https://doi.org/10.1029/2021JA029415
Publikationsdatum
09-2021
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie, 103004 Astrophysik
Schlagwörter
ASJC Scopus Sachgebiete
Geophysics, Space and Planetary Science
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/e0626f94-0ede-481e-b79c-71dbdb1ef898