Three-dimensional observations of gyrating ion distributions far upstream from the Earth's bow shock and their association with low-frequency waves

2001 ◽  
Vol 106 (A4) ◽  
pp. 5731-5742 ◽  
Author(s):  
K. Meziane ◽  
C. Mazelle ◽  
R. P. Lin ◽  
D. LeQuéau ◽  
D. E. Larson ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Low Frequency ◽  
Bow Shock ◽  
Ion Distributions ◽  
Earth’S Bow Shock ◽  
Low Frequency Waves

WIND observation of gyrating-like ion distributions and low frequency waves upstream from the Earth's bow shock

1997 ◽  
Vol 20 (4-5) ◽  
pp. 703-706 ◽  
Author(s):  
K. Meziane ◽  
C. Mazelle ◽  
C. d'Uston ◽  
H. Rème ◽  
R.P. Lin ◽  
...  
Keyword(s):  
Low Frequency ◽  
Bow Shock ◽  
Wind Observation ◽  
Ion Distributions ◽  
Earth’S Bow Shock ◽  
Low Frequency Waves

Ultra low frequency waves at the Earth's bow shock

1995 ◽  
Vol 15 (8-9) ◽  
pp. 285-296 ◽  
Author(s):  
C.T Russell ◽  
M.H Farris
Keyword(s):  
Low Frequency ◽  
Bow Shock ◽  
Earth’S Bow Shock ◽  
Low Frequency Waves

scholarly journals Helium in the Earth's foreshock: a global Vlasiator survey

2020 ◽  
Author(s):  
Markus Battarbee ◽  
Xóchitl Blanco-Cano ◽  
Lucile Turc ◽  
Primoz Kajdic ◽  
Vertti Tarvus ◽  
...  
Keyword(s):  
Low Frequency ◽  
Alpha Particles ◽  
Compressive Wave ◽  
Energetic Ions ◽  
Ion Distributions ◽  
Hot Plasma ◽  
Earth’S Bow Shock ◽  
Composition Analyzer ◽  
Ion Profiles ◽  
Low Frequency Waves

<p>The foreshock is a region of space in front of the Earth's bow shock, extending along the interplanetary magnetic field. It is permeated by ions and electrons reflected at the shock, low-frequency waves, and various plasma transients. The ion foreshock is dominated by a number of proton populations such as field-aligned beams, gyrating distributions and diffuse ions, as well as proton-excited waves. As the solar wind can contain a significant fraction of helium, it is of great interest to investigate how alpha-particles (He<sup>2+</sup>) are reflected into forming their own foreshock. We investigate the extent of the helium foreshock in relation to foreshock ultra-low frequency waves and protons using Vlasiator, a global hybrid-Vlasov simulation. We confirm a number of historical spacecraft observations at the foreshock regions associated with field-aligned beams, gyrating ion distributions, and specularly reflected particles, performing the first numerical global survey of the helium foreshock. We present wavelet analysis at multiple positions within the foreshock and evaluate the dynamics of gyrating ion populations in response to the transverse and compressive wave components. We also present Magnetosphere Multiscale (MMS) spacecraft crossings of the foreshock edge and compare Hot Plasma Composition Analyzer (HPCA) measurements of energetic ions with our simulation data, showing the variability of the foreshock edge suprathermal ion profiles.</p>

scholarly journals Helium in the Earth’s foreshock: a global Vlasiator survey

2020 ◽  
Author(s):  
Markus Battarbee ◽  
Xochitl Blanco-Cano ◽  
Lucile Turc ◽  
Primož Kajdič ◽  
Andreas Johlander ◽  
...  
Keyword(s):  
Specular Reflection ◽  
Cone Angle ◽  
Low Frequency ◽  
Bow Shock ◽  
Wave Interactions ◽  
Global Context ◽  
Ulf Wave ◽  
Ion Interactions ◽  
Earth’S Bow Shock ◽  
Low Frequency Waves

Abstract. The foreshock is a region of space upstream of the Earth's bow shock extending along the interplanetary magnetic field. It is permeated by shock-reflected ions and electrons, low-frequency waves, and various plasma transients. We investigate the extent of the He2+ foreshock using Vlasiator, a global hybrid-Vlasov simulation. We perform the first numerical global survey of the helium foreshock, and interpret some historical foreshock observations in a global context. The foreshock edge is populated by both proton and helium field-aligned beams, with the proton foreshock extending slightly further into the solar wind than the helium foreshock, and both extend well beyond the ULF wave foreshock. We compare our simulation results with MMS HPCA measurements, showing how the gradient of suprathermal ion densities at the foreshock crossing can vary between events. Our analysis suggests that the IMF cone angle and the associated shock obliquity gradient can play a role in explaining this differing behaviour. We also investigate wave-ion-interactions with wavelet analysis and show that the dynamics and heating of He2+ must result from proton-driven ULF waves. Enhancements in ion agyrotropy are found in relation to, e.g., the ion foreshock boundary, the ULF foreshock boundary, and specular reflection of ions at the bow shock. We show that specular reflection can describe many of the foreshock ion VDF enhancements. Wave-wave-interactions deep in the foreshock cause decoherence of wavefronts, allowing He2+ the be scattered less than protons.

Attenuation distance of low frequency waves upstream of the pre-dawn bow shock: GEOTAIL and ISEE 3 comparison

1995 ◽  
Vol 22 (2) ◽  
pp. 81-84 ◽  
Author(s):  
T. Sugiyama ◽  
T. Terasawa ◽  
H. Kawano ◽  
T. Yamamoto ◽  
S. Kokubun ◽  
...  
Keyword(s):  
Low Frequency ◽  
Bow Shock ◽  
Low Frequency Waves

scholarly journals Ion distributions upstream and downstream of the Earth's bow shock: first results from Vlasiator

2013 ◽  
Vol 31 (12) ◽  
pp. 2207-2212 ◽  
Author(s):  
D. Pokhotelov ◽  
S. von Alfthan ◽  
Y. Kempf ◽  
R. Vainio ◽  
H. E. J. Koskinen ◽  
...  
Keyword(s):  
Distribution Functions ◽  
Bow Shock ◽  
Three Dimensions ◽  
Ion Distribution ◽  
Plasma Kinetics ◽  
Ion Distributions ◽  
Spatial Dimensions ◽  
First Results ◽  
Earth’S Bow Shock

Abstract. A novel hybrid-Vlasov code, Vlasiator, is developed for global simulations of magnetospheric plasma kinetics. The code is applied to model the collisionless bow shock on scales of the Earth's magnetosphere in two spatial dimensions and three dimensions in velocity space retrieving ion distribution functions over the entire foreshock and magnetosheath regions with unprecedented detail. The hybrid-Vlasov approach produces noise-free uniformly discretized ion distribution functions comparable to those measured in situ by spacecraft. Vlasiator can reproduce features of the ion foreshock and magnetosheath well known from spacecraft observations, such as compressional magnetosonic waves generated by backstreaming ion populations in the foreshock and mirror modes in the magnetosheath. An overview of ion distributions from various regions of the bow shock is presented, demonstrating the great opportunities for comparison with multi-spacecraft observations.

Electron Scattering by Low-frequency Whistler Waves at Earth’s Bow Shock

2019 ◽  
Vol 886 (1) ◽  
pp. 53 ◽  
Author(s):  
M. Oka ◽  
F. Otsuka ◽  
S. Matsukiyo ◽  
L. B. Wilson ◽  
M. R. Argall ◽  
...  
Keyword(s):  
Electron Scattering ◽  
Low Frequency ◽  
Bow Shock ◽  
Whistler Waves ◽  
Earth’S Bow Shock
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