Work

Spatial Dependence of Ion‐Kinetic Instabilities in the Earth's Magnetosheath: MMS Observations

Year: 2025

Type: article

Abstract: The Earth's magnetosheath plasma frequently exhibits unequal temperatures parallel and perpendicular to the background magnetic field. This temperature anisotropy is crucial in exciting and dissipating electromagnetic fluctuations in various plasma environments. Leveraging a comprehensive dataset comprising sub‐ion scale measurements from NASA's Magnetospheric Multiscale Mission, our study unveils insights into the spatial evolution and parametric dependence of different ion kinetic instabilities within the Earth's magnetosheath. We observe a remarkable spatial dependence on the occurrence of kinetic instabilities. The condition for the mirror‐mode instability exhibits a significantly higher prevalence near the subsolar magnetopause compared to the flank regions. The condition for the oblique firehose instability is more prominent near the bow shock region than in the vicinity of the magnetopause. Furthermore, the occurrence of these instabilities and their spatial distribution are linked to the plasma's upstream conditions. Our study offers new insights into the nature of ion kinetic instabilities in the Earth's magnetosheath and similar plasma environments.

Source: Journal of Geophysical Research Space Physics

DOI: 10.1029/2024ja033463

Authors: Wence Jiang, Hui Li, Zhongwei Yang, Daniel Verscharen, Chi Wang

Institutions: National Space Science Center, State Key Laboratory of Space Weather, University of Chinese Academy of Sciences, University College London

Language: English

Topic: Ionosphere and magnetosphere dynamics

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,070

Funders: National Natural Science Foundation of China, Science and Technology Facilities Council