Kinetic‐Size Magnetic Holes in the Terrestrial Foreshock Region. Issue 8 (23rd April 2022)

• Record Type: Journal Article
• Authors: Huang, S. Y.; Wei, Y. Y.; Zhao, J. S.; Yuan, Z. G.; Deng, X. H.; Jiang, K.; Xu, S. B.; Zhang, J.; Xiong, Q. Y.; Zhang, Z. H.; Yu, L.; Lin, R. T.
• Is Part Of: Geophysical research letters. Volume 49:Issue 8(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-23
• Subjects: kinetic‐size magnetic holes -- foreshock region -- electron vortex -- sunward propagating; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2021GL093813
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Kinetic‐size magnetic holes (KSMHs) can accelerate and heat the particles, resulting the energy dissipation in space plasmas. KSMHs in the terrestrial foreshock region are statistically investigated based on the Magnetospheric Multiscale data from October 2015 to December 2019. A total of 98 KSMHs are successfully selected, and most of them are accompanied by electron vortices. The fluxes of electrons at ∼90° of pitch angle enhance inside the magnetic holes, where the perpendicular and total electron temperature increase, and the parallel electron temperature slightly decreases inside these magnetic holes. Moreover, we reveal a novel phenomenon that a lot of the observed KSMHs are probably moving toward the Sun in the plasma flow frame. Such sunward propagating KSMHs are detected for the first time in the foreshock region. We propose that these observed KSMHs are probably generated in the foreshock region and then propagate to the Sun. Plain Language Summary: Magnetic hole, characterized by the significant decrease of magnetic strength, is usually observed in the planetary magnetosphere. Kinetic‐size magnetic holes (KSMHs) with the scale below ion gyroradius have attracted much interest in recent years. KSMHs can accelerate and heat the particles, resulting the energy dissipation in space plasmas. Based on the Magnetospheric Multiscale data, KSMHs in the terrestrial foreshock region are statistically investigated for the first time. We reveal some novel phenomenon for the observed KSMHs in the foreshock region. Key Points: We present the observational evidence of kinetic‐size magnetic holes (KSMHs) in the terrestrial foreshock region A lot of the observed KSMHs are probably moving toward the Sun in the plasma flow frame These observed KSMHs are probably generated in the foreshock region and then propagate toward the Sun