Foreshock Properties at Typical and Enhanced Interplanetary Magnetic Field Strengths: Results From Hybrid-Vlasov Simulations

Research output: Contribution to journalArticleScientificpeer-review

Standard

Foreshock Properties at Typical and Enhanced Interplanetary Magnetic Field Strengths : Results From Hybrid-Vlasov Simulations. / Turc, L.; Ganse, U.; Pfau-Kempf, Y.; Hoilijoki, S.; Battarbee, M.; Juusola, L.; Jarvinen, R.; Brito, T.; Grandin, M.; Palmroth, M.

In: Journal of geophysical research: Space physics, Vol. 123, No. 7, 07.2018, p. 5476-5493.

Research output: Contribution to journalArticleScientificpeer-review

Harvard

Turc, L, Ganse, U, Pfau-Kempf, Y, Hoilijoki, S, Battarbee, M, Juusola, L, Jarvinen, R, Brito, T, Grandin, M & Palmroth, M 2018, 'Foreshock Properties at Typical and Enhanced Interplanetary Magnetic Field Strengths: Results From Hybrid-Vlasov Simulations' Journal of geophysical research: Space physics, vol. 123, no. 7, pp. 5476-5493. https://doi.org/10.1029/2018JA025466

APA

Vancouver

Author

Turc, L. ; Ganse, U. ; Pfau-Kempf, Y. ; Hoilijoki, S. ; Battarbee, M. ; Juusola, L. ; Jarvinen, R. ; Brito, T. ; Grandin, M. ; Palmroth, M. / Foreshock Properties at Typical and Enhanced Interplanetary Magnetic Field Strengths : Results From Hybrid-Vlasov Simulations. In: Journal of geophysical research: Space physics. 2018 ; Vol. 123, No. 7. pp. 5476-5493.

Bibtex - Download

@article{88e50db9524441208d462c789f130de6,
title = "Foreshock Properties at Typical and Enhanced Interplanetary Magnetic Field Strengths: Results From Hybrid-Vlasov Simulations",
abstract = "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.",
keywords = "Bow shock, Foreshock, Kinetic simulations, Numerical simulations, Plasma waves, ULF waves",
author = "L. Turc and U. Ganse and Y. Pfau-Kempf and S. Hoilijoki and M. Battarbee and L. Juusola and R. Jarvinen and T. Brito and M. Grandin and M. Palmroth",
year = "2018",
month = "7",
doi = "10.1029/2018JA025466",
language = "English",
volume = "123",
pages = "5476--5493",
journal = "Journal of geophysical research: Space physics",
issn = "2169-9380",
number = "7",

}

RIS - Download

TY - JOUR

T1 - Foreshock Properties at Typical and Enhanced Interplanetary Magnetic Field Strengths

T2 - Results From Hybrid-Vlasov Simulations

AU - Turc, L.

AU - Ganse, U.

AU - Pfau-Kempf, Y.

AU - Hoilijoki, S.

AU - Battarbee, M.

AU - Juusola, L.

AU - Jarvinen, R.

AU - Brito, T.

AU - Grandin, M.

AU - Palmroth, M.

PY - 2018/7

Y1 - 2018/7

N2 - 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.

AB - 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.

KW - Bow shock

KW - Foreshock

KW - Kinetic simulations

KW - Numerical simulations

KW - Plasma waves

KW - ULF waves

UR - http://www.scopus.com/inward/record.url?scp=85050384782&partnerID=8YFLogxK

U2 - 10.1029/2018JA025466

DO - 10.1029/2018JA025466

M3 - Article

VL - 123

SP - 5476

EP - 5493

JO - Journal of geophysical research: Space physics

JF - Journal of geophysical research: Space physics

SN - 2169-9380

IS - 7

ER -

ID: 27142004