DOI: 10.1029/2018JA025466
Scopus记录号: 2-s2.0-85050384782
论文题名: Foreshock Properties at Typical and Enhanced Interplanetary Magnetic Field Strengths: Results From Hybrid-Vlasov Simulations
作者: Turc L. ; Ganse U. ; Pfau-Kempf Y. ; Hoilijoki S. ; Battarbee M. ; Juusola L. ; Jarvinen R. ; Brito T. ; Grandin M. ; Palmroth M.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 7 起始页码: 5476
结束页码: 5493
语种: 英语
英文关键词: bow shock
; foreshock
; kinetic simulations
; numerical simulations
; plasma waves
; ULF waves
英文摘要: In this paper, we present a detailed study of the effects of the interplanetary magnetic field (IMF) strength on the foreshock properties at small and large scales. Two simulation runs performed with the hybrid-Vlasov code Vlasiator with identical setup but with different IMF strengths, namely, 5 and 10 nT, are compared. We find that the bow shock position and shape are roughly identical in both runs, due to the quasi-radial IMF orientation, in agreement with previous magnetohydrodynamic simulations and theory. Foreshock waves develop in a broader region in the higher IMF strength run, which we attribute to the larger growth rate of the waves. The velocity of field-aligned beams remains essentially the same, but their density is generally lower when the IMF strength increases, due to the lower Mach number. Also, we identify in the regular IMF strength run ridges of suprathermal ions which disappear at higher IMF strength. These structures may be a new signature of the foreshock compressional boundary. The foreshock wave field is structured over smaller scales in higher IMF conditions, due to both the period of the foreshock waves and the transverse extent of the wave fronts being smaller. While the foreshock is mostly permeated by monochromatic waves at typical IMF strength, we find that magnetosonic waves at different frequencies coexist in the other run. They are generated by multiple beams of suprathermal ions, while only a single beam is observed at typical IMF strength. The consequences of these differences for solar wind-magnetosphere coupling are discussed. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113593
Appears in Collections: 气候减缓与适应
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作者单位: Department of Physics, University of Helsinki, Helsinki, Finland; Now at Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO, United States; Finnish Meteorological Institute, Helsinki, Finland; Department of Electronics and Nanoengineering, School of Electrical Engineering, Aalto University, Espoo, Finland
Recommended Citation:
Turc L.,Ganse U.,Pfau-Kempf Y.,et al. Foreshock Properties at Typical and Enhanced Interplanetary Magnetic Field Strengths: Results From Hybrid-Vlasov Simulations[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(7)