Ion-scale current sheets embedded in the reconnection-jet shear layer of the near-Sun heliospheric current sheet
4 affiliations
- 1Department of Astronomy and Space Science, Chungbuk National University
- 2Space Sciences Laboratory, University of California
- 3Department of Earth Science Education, Chungbuk National University
- 4New Mexico Consortium
Abstract
Context . Magnetic reconnection in the heliospheric current sheet (HCS) plays an important role in restructuring solar-wind magnetic topology and generating plasma jets and magnetic islands. While large-scale signatures of HCS reconnection have been reported in many observational studies, the kinetic-scale structure embedded within reconnection regions remains less well understood.
Aims . We aim to investigate the ion-scale current sheets (CSs) embedded within an HCS reconnection region and their relationship to the flow-shear layer at the edge of a reconnection jet.
Methods . We analyzed an HCS crossing observed by the Parker Solar Probe on March 29, 2024, using high-time-resolution magnetic-field measurements. We focused on ion-scale magnetic transitions within two brief intervals of flow shear layers at the edges of the reconnection jet and examined them in a local LMN coordinate system.
Results . Twelve representative CSs are identified, whose duration is on average ∼0.06 s, corresponding to spatial scales of only a few ion inertial lengths. Eight of the twelve CSs exhibit localized bipolar variations in the transverse B M component, with several also showing bifurcated B L profiles characterized by plateau-like structure. In the remaining events, strong transverse fluctuations prevented the identification of a clear bipolar B M signature.
Conclusions . The reconnection-jet shear layer in the HCS may serve as an active site that hosts a chain of ion-scale CSs. This provides new insight into the multiscale structure of HCS reconnection and suggests that flow shear layers may play an important role in generating secondary kinetic-scale structures.
Related
- Bifurcations in the Heliosphere: Global-scale Coronal Pseudostreamer Evolution and the Creation of Secondary Heliospheric Current Sheets
- Current Sheets and Magnetic Reconnection statistics by Solar Orbiter at few to tens of Ion Inertial Lengths II: Conditions for Reconnection, and Current Sheet Planarity
- Current Sheets and Magnetic Reconnection statistics by Solar Orbiter at few to tens of Ion Inertial Lengths I: Energy Dissipation
- Dynamical and thermal evolution of localized reconnecting current sheets under varying guide fields in the solar corona
- Power-Law Injection Spectrum from an Ensemble of Reconnecting Current Sheets
BibTeX
@article{lee2026ionscale,
title = {{Ion-scale current sheets embedded in the reconnection-jet shear layer of the near-Sun heliospheric current sheet}},
author = {Dae-Young Lee and Dooyoung Choi and Kyung-Eun Choi and Sung Jun Noh},
journal = {Astronomy \& Astrophysics},
year = {2026},
month = oct,
doi = {10.1051/0004-6361/202661982},
url = {https://www.aanda.org/10.1051/0004-6361/202661982},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Ion-scale current sheets embedded in the reconnection-jet shear layer of the near-Sun heliospheric current sheet
AU - Dae-Young Lee
AU - Dooyoung Choi
AU - Kyung-Eun Choi
AU - Sung Jun Noh
PY - 2026
DA - 2026/10/29
JO - Astronomy & Astrophysics
DO - 10.1051/0004-6361/202661982
UR - https://www.aanda.org/10.1051/0004-6361/202661982
AB - Context . Magnetic reconnection in the heliospheric current sheet (HCS) plays an important role in restructuring solar-wind magnetic topology and generating plasma jets and magnetic islands. While large-scale signatures of HCS reconnection have been reported in many observational studies, the kinetic-scale structure embedded within reconnection regions remains less well understood. Aims . We aim to investigate the ion-scale current sheets (CSs) embedded within an HCS reconnection region and their relationship to the flow-shear layer at the edge of a reconnection jet. Methods . We analyzed an HCS crossing observed by the Parker Solar Probe on March 29, 2024, using high-time-resolution magnetic-field measurements. We focused on ion-scale magnetic transitions within two brief intervals of flow shear layers at the edges of the reconnection jet and examined them in a local LMN coordinate system. Results . Twelve representative CSs are identified, whose duration is on average ∼0.06 s, corresponding to spatial scales of only a few ion inertial lengths. Eight of the twelve CSs exhibit localized bipolar variations in the transverse B M component, with several also showing bifurcated B L profiles characterized by plateau-like structure. In the remaining events, strong transverse fluctuations prevented the identification of a clear bipolar B M signature. Conclusions . The reconnection-jet shear layer in the HCS may serve as an active site that hosts a chain of ion-scale CSs. This provides new insight into the multiscale structure of HCS reconnection and suggests that flow shear layers may play an important role in generating secondary kinetic-scale structures.
SN - 0004-6361
SN - 1432-0746
ER -