We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Prompt Disappearance of Magnetospheric Chorus Waves Caused by High‐Speed Magnetosheath Jets.
- Authors
Zhou, Xuan; Gao, Xinliang; Lu, Quanming; Hajra, Rajkumar; Ke, Yangguang; Chen, Rui; Ma, Jiuqi
- Abstract
Magnetosheath high‐speed jets (HSJs), localized impulses of dynamic pressure, are attracting growing attention due to their geoeffectiveness. However, how HSJs modulate chorus waves in the magnetosphere still remains unclear. Utilizing combined observations of the Time History of Events and Macroscale Interactions during Substorms satellites A and E, we report, for the first time, the prompt disappearance of the magnetospheric chorus waves caused by a HSJ. Such wave disappearance is directly due to the flux drop of energetic electrons (∼10–100 keV), leading to the cessation of wave generation, which is supported by the linear theoretical analysis. We propose that the flux drop results from the local indentation of magnetopause after the HSJ impact, where two new smaller magnetic mirrors are formed off the equator and part of electrons are then expelled by the mirror force. The HSJs should be an important factor in modulating chorus waves because of their high occurrence rate. Plain Language Summary: The solar wind with enhanced dynamic pressure can globally compress the dayside magnetosphere, causing the excitation and intensification of chorus waves. Besides the enhancement of solar wind RAM pressure, there also exists the ion‐scale dynamic pressure impulse in the magnetosheath, known as a high‐speed jet (HSJ), even during quiet solar wind conditions. Previous studies have shown that the HSJs have a high occurrence rate and they are geoeffective (causing disturbances in the Earth's magnetosphere). However, it is still unknown whether HSJs can modulate chorus waves in the magnetosphere. In this study, based on joint observations of THEMIS‐A and E probes, we report the prompt disappearance of chorus waves in the magnetosphere caused by the HSJs. We propose that a HSJ causes the local indentation of the dayside geomagnetic fields at the magnetic equator, and creates two small magnetic mirrors. Consequently, the poleward mirror force will expel some of the electrons from the equator, and lead to a significant decrease of the electron flux. Finally, the generation of chorus waves will stop due to the lack of energy sources. This study reveals that HSJs are a new and important factor in modulating chorus waves in the magnetosphere. Key Points: With joint observations of THMIS‐A and THMIS‐E, we first report the prompt disappearance of chorus waves due to the high‐speed jets (HSJs)HSJs cause the local indentation of the magnetopause, creating two new magnetic mirrors, and electrons are expelled by the mirror forceThe electron flux drop leads to the cessation of the chorus wave generation, that is, the disappearance of waves
- Subjects
SOLAR wind; DYNAMIC pressure; MAGNETOPAUSE; GEOMAGNETISM; MAGNETIC fields; WIND pressure
- Publication
Journal of Geophysical Research. Space Physics, 2024, Vol 129, Issue 6, p1
- ISSN
2169-9380
- Publication type
Article
- DOI
10.1029/2024JA032576