Multi‐Event Analysis of STEVE, SAR Arc, and Red/Green Arc at Subauroral Latitudes Using Data From Ground Optical and Radio Instruments and the Arase and Van Allen Probes Satellites

Abstract Strong Thermal Emission Velocity Enhancement (STEVE) is a latitudinally narrow, purple‐band emission observed at subauroral latitudes. Stable Auroral Red (SAR) arcs characterized by major red emission, and red/green arcs with both red and green emissions also occur at subauroral latitudes. Characteristics of magnetospheric source plasma and electromagnetic fields of these three types of arcs have not been fully understood because of the limited conjugate observations between magnetosphere and the ground. In this study, we report 11 conjugate observations (2 STEVEs, 7 SAR arcs, and 2 red/green arcs), using all‐sky images obtained at seven ground stations over more than four years from January 2017 to April 2021 and magnetospheric satellites (Arase and Van Allen Probes). We found that, in the inner magnetosphere, the source region of STEVEs and red/green arcs were located outside the plasmasphere, and that of the SAR arc was in the region of spatial overlap between the plasmasphere and ring current region. Electromagnetic waves at frequencies below 1 Hz were observed for STEVEs and red/green arcs. SuperDARN radar data showed a strong westward plasma flow in the ionosphere, especially during STEVE events, whereas the plasma flows associated with SAR arcs and red/green arcs were generally weaker and variable. The STEVE and SAR arc can appear simultaneously at slightly different latitudes and STEVEs and red/green arcs can transform into SAR arcs. These first comprehensive ground‐satellite measurements of three types of subauroral‐latitude auroras increase our understanding on similarlity, differences, and coupling of these auroras in the ionosphere and the magnetosphere.

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Publication Details

Journal
Journal of Geophysical Research Space Physics
Published
2025-02-01
DOI
https://doi.org/10.1029/2024ja032793
Citations
2
Primary Topic
Ionosphere and magnetosphere dynamics
Type
article
Field-Weighted Citation Impact
2.31

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article

Multi‐Event Analysis of STEVE, SAR Arc, and Red/Green Arc at Subauroral Latitudes Using Data From Ground Optical and Radio Instruments and the Arase and Van Allen Probes Satellites

Yoshiya Kasahara, Iku Shinohara, Fuminori Tsuchiya, H. O. Funsten et al.
2 citations
Journal of Geophysical Research Space Physics
Ionosphere and magnetosphere dynamics
2.31
article

Multi‐Event Analysis of STEVE, SAR Arc, and Red/Green Arc at Subauroral Latitudes Using Data From Ground Optical and Radio Instruments and the Arase and Van Allen Probes Satellites

Yoshiya Kasahara, Iku Shinohara, Fuminori Tsuchiya, H. O. Funsten, Igor Poddelsky, J. M. Ruohoniemi, Shoichiro Yokota, Shin‐ichiro Oyama, A. Oksanen, Kazushi Asamura, Rumiko Sugimura, B.‐J. Wang, K. Keika, Atsushi Kumamoto, Sunny W. Y. Tam, G. D. Reeves, Tomoaki Hori, Ayako Matsuoka, Y. Kazama, T. F. Chang, Shiang‐Yu Wang, C. W. Smith, Simon Shepherd, Akira Kadokura, H. E. Spence, Satoshi Kasahara, K. Shiokawa, Chae‐Woo Jun, Н. Нишитани, Yoshizumi Miyoshi, Martin G. Connors, Atsuki Shinbori, Yuichi Otsuka
article en
2 citations

Abstract

Abstract Strong Thermal Emission Velocity Enhancement (STEVE) is a latitudinally narrow, purple‐band emission observed at subauroral latitudes. Stable Auroral Red (SAR) arcs characterized by major red emission, and red/green arcs with both red and green emissions also occur at subauroral latitudes. Characteristics of magnetospheric source plasma and electromagnetic fields of these three types of arcs have not been fully understood because of the limited conjugate observations between magnetosphere and the ground. In this study, we report 11 conjugate observations (2 STEVEs, 7 SAR arcs, and 2 red/green arcs), using all‐sky images obtained at seven ground stations over more than four years from January 2017 to April 2021 and magnetospheric satellites (Arase and Van Allen Probes). We found that, in the inner magnetosphere, the source region of STEVEs and red/green arcs were located outside the plasmasphere, and that of the SAR arc was in the region of spatial overlap between the plasmasphere and ring current region. Electromagnetic waves at frequencies below 1 Hz were observed for STEVEs and red/green arcs. SuperDARN radar data showed a strong westward plasma flow in the ionosphere, especially during STEVE events, whereas the plasma flows associated with SAR arcs and red/green arcs were generally weaker and variable. The STEVE and SAR arc can appear simultaneously at slightly different latitudes and STEVEs and red/green arcs can transform into SAR arcs. These first comprehensive ground‐satellite measurements of three types of subauroral‐latitude auroras increase our understanding on similarlity, differences, and coupling of these auroras in the ionosphere and the magnetosphere.

Journal of Geophysical Research Space PhysicsVol. 130(2)
Kanazawa University (JP), Dartmouth College (US), Institute of Astronomy and Astrophysics, Academia Sinica (TW), Los Alamos National Laboratory (US), University of New Hampshire (US), Tokyo University of Science (JP), The Graduate University for Advanced Studies, SOKENDAI (JP), Tohoku University (JP), Japan Aerospace Exploration Agency (JP), National Institute of Polar Research (JP), Osaka Health Science University (JP), Institute of Cosmophysical Research and Radio Wave Propagation (RU), Institute of Space and Astronautical Science (JP), Institute of Science Tokyo (JP), Nagoya University (JP), Virginia Tech (US), Athabasca University (CA), National Cheng Kung University (TW), The University of Osaka (JP)
Athabasca University, Dartmouth College, Canada Foundation for Innovation, Nagoya University, Natural Sciences and Engineering Research Council of Canada
Openalex Percentile: Top 13%
Ionosphere and magnetosphere dynamics
2.31
DOIOpen Access PDFOpenAlex
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