A case study of EMIC waves associated with sudden geosynchronous magnetic field changes

2017 ◽  
Vol 122 (3) ◽  
pp. 3322-3341 ◽  
Author(s):  
Khan‐Hyuk Kim ◽  
Yoshiharu Omura ◽  
Ho Jin ◽  
Junga Hwang
Keyword(s):  
Magnetic Field ◽  
Emic Waves

Magnetic Current Imaging Techniques: Comparative Case Studies

2004 ◽  
Author(s):  
Olivier Crépel ◽  
Philippe Descamps ◽  
Patrick Poirier ◽  
Romain Desplats ◽  
Philippe Perdu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Integrated Circuits ◽  
Case Studies ◽  
Flip Chip ◽  
Imaging Techniques ◽  
Optimal Domain ◽  
Magnetic Current ◽  
Comparative Case Studies ◽  
Current Flows

Abstract Magnetic field based techniques have shown great capabilities for investigation of current flows in integrated circuits (ICs). After reviewing the performances of SQUID, GMR (hard disk head technologies) and MTJ existing sensors, we will present results obtained on various case studies. This comparison will show the benefit of each approach according to each case study (packaged devices, flip-chip circuits, …). Finally we will discuss on the obtained results to classify current techniques, optimal domain of applications and advantages.

scholarly journals A subauroral polarization stream driven by field‐aligned currents associated with precipitating energetic ions caused by EMIC waves: A case study

2016 ◽  
Vol 121 (2) ◽  
pp. 1696-1705 ◽  
Author(s):  
Zhigang Yuan ◽  
Ying Xiong ◽  
Zheng Qiao ◽  
Haimeng Li ◽  
Shiyong Huang ◽  
...  
Keyword(s):  
Energetic Ions ◽  
Emic Waves

Direct measurements of cold and hot plasma composition and EMIC waves in the outer magnetosphere: Implications for inner magnetosphere wave-particle interactions

2021 ◽  
Author(s):  
Justin Lee ◽  
Drew Turner ◽  
Sarah Vines ◽  
Robert Allen ◽  
Sergio Toledo-Redondo
Keyword(s):  
Unstable Wave ◽  
Linear Wave ◽  
Plasma Composition ◽  
Inner Magnetosphere ◽  
Hot Plasma ◽  
Emic Wave ◽  
Direct Measurements ◽  
Wave Numbers ◽  
Emic Waves

<p>Although thorough characterization of magnetospheric ion composition is rare for EMIC wave studies, convective processes that occur more frequently in Earth’s outer magnetosphere have allowed the Magnetospheric Multiscale (MMS) satellites to make direct measurements of the cold and hot plasma composition during EMIC wave activity. We will present an observation and linear wave modeling case study conducted on EMIC waves observed during a perturbed activity period in the outer dusk-side magnetosphere. During the two intervals investigated for the case study, the MMS satellites made direct measurements of cold plasmaspheric plasma in addition to multiple hot ion components at the same time as EMIC wave emissions were observed. Applying the in-situ plasma composition data to wave modeling, we find that wave growth rate is impacted by the complex interactions between the cold as well as the hot ion components and ambient plasma conditions. In addition, we observe that linear wave properties (unstable wave numbers and band structure) can significantly evolve with changes in cold and hot ion composition. Although the modeling showed the presence of dense cold ions can broaden the range of unstable wave numbers, consistent with previous work, the hot heavy ions that were more abundant nearer storm main phase could limit the growth of EMIC waves to smaller wave numbers. In the inner magnetosphere, where higher cold ion density is expected, the ring current heavy ions could also be more intense near storm-time, possibly resulting in conditions that limit the interactions of EMIC waves with trapped radiation belt electrons to multi-MeV energies. Additional investigation when direct measurements of cold and hot plasma composition are available could improve understanding of EMIC waves and their interactions with trapped energetic particles in the inner magnetosphere.</p>

scholarly journals A case study of the plasma in the magneto-sheath using the numerical magnetosheath-magnetosphere model and THEMIS measure-ments

2018 ◽  
Vol 145 ◽  
pp. 03004
Author(s):  
Polya Dobreva ◽  
Olga Nitcheva ◽  
Monio Kartalev
Keyword(s):  
Magnetic Field ◽  
Field Model ◽  
Specific Aspect ◽  
Plasma Parameters ◽  
Ion Density ◽  
Magnetic Field Model ◽  
Wind Spacecraft ◽  
The Mean ◽  
The Magnetic Field

This paper presents a case study of the plasma parameters in the magnetosheath, based on THEMIS measurements. As a theoretical tool we apply the self-consistent magnetosheath-magnetosphere model. A specific aspect of the model is that the positions of the bow shock and the magnetopause are self-consistently determined. In the magnetosheath the distribution of the velocity, density and temperature is calculated, based on the gas-dynamic theory. The magnetosphere module allows for the calculation of the magnetopause currents, confining the magnetic field into an arbitrary non-axisymmetric magnetopause. The variant of the Tsyganenko magnetic field model is applied as an internal magnetic field model. As solar wind monitor we use measurements from the WIND spacecraft. The results show that the model quite well reproduces the values of the ion density and velocity in the magnetosheath. The simlicity of the model allows calulations to be perforemed on a personal computer, which is one of the mean advantages of our model.

scholarly journals Scattering of field-aligned beam ions upstream of Earth's bow shock

2007 ◽  
Vol 25 (3) ◽  
pp. 785-799 ◽  
Author(s):  
A. Kis ◽  
M. Scholer ◽  
B. Klecker ◽  
H. Kucharek ◽  
E. A. Lucek ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Measurements ◽  
Bow Shock ◽  
Ion Distribution ◽  
Parallel Side ◽  
Earth’S Bow Shock ◽  
High Mach ◽  
The Magnetic Field

Abstract. Field-aligned beams are known to originate from the quasi-perpendicular side of the Earth's bow shock, while the diffuse ion population consists of accelerated ions at the quasi-parallel side of the bow shock. The two distinct ion populations show typical characteristics in their velocity space distributions. By using particle and magnetic field measurements from one Cluster spacecraft we present a case study when the two ion populations are observed simultaneously in the foreshock region during a high Mach number, high solar wind velocity event. We present the spatial-temporal evolution of the field-aligned beam ion distribution in front of the Earth's bow shock, focusing on the processes in the deep foreshock region, i.e. on the quasi-parallel side. Our analysis demonstrates that the scattering of field-aligned beam (FAB) ions combined with convection by the solar wind results in the presence of lower-energy, toroidal gyrating ions at positions deeper in the foreshock region which are magnetically connected to the quasi-parallel bow shock. The gyrating ions are superposed onto a higher energy diffuse ion population. It is suggested that the toroidal gyrating ion population observed deep in the foreshock region has its origins in the FAB and that its characteristics are correlated with its distance from the FAB, but is independent on distance to the bow shock along the magnetic field.

scholarly journals A Case Study of Transversely Heated Low‐Energy Helium Ions by EMIC Waves in the Plasmasphere

2021 ◽  
Vol 126 (2) ◽  
Author(s):  
Khan‐Hyuk Kim ◽  
Hyuck‐Jin Kwon ◽  
Junhyun Lee ◽  
Ho Jin ◽  
Jungjoon Seough
Keyword(s):  
Low Energy ◽  
Helium Ions ◽  
Emic Waves

scholarly journals Artifacts in magnetic force microscopy under in-plane applied magnetic field: Magnetic bubble as a case study

2020 ◽  
Vol 500 ◽  
pp. 166296
Author(s):  
Ibrahim Cinar ◽  
Daniel Lacour ◽  
Francois Montaigne ◽  
Vito Puliafito ◽  
Sebastien Petit Watelot ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Magnetic Bubble ◽  
Force Microscopy

scholarly journals The current sheet flapping motions induced by non-adiabatic ions: case study

2018 ◽  
Author(s):  
Xinhua Wei ◽  
Chunlin Cai ◽  
Henri Rème ◽  
Iannis Dandouras ◽  
George Parks
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Field Line ◽  
Magnetic Field Line ◽  
Plasma Sheet ◽  
Plasma Sources ◽  
Shear Structures ◽  
Particle Population ◽  
Alternating Bending

Abstract. In this paper, we analyzed the y-component of magnetic field line curvature in the plasma sheet and found that there are two kinds of shear structures of the flapping current sheet, i.e. symmetric and antisymmetric. The alternating bending orientations of guiding field are exactly corresponding to alternating north-south asymmetries of the bouncing ion population in the sheet center. Those alternating asymmetric plasma sources consequently induce the current sheet flapping motion as a driver. In addition, a substantial particle population with dawnward motion was observed in the center of a bifurcated current sheet. This population is identified as the quasi-adiabatic particles, and provides a net current opposite to the conventional cross-tail current.

scholarly journals Radial dependence of foreshock cavities: a case study

2004 ◽  
Vol 22 (12) ◽  
pp. 4143-4151 ◽  
Author(s):  
D. G. Sibeck ◽  
K. Kudela ◽  
T. Mukai ◽  
Z. Nemecek ◽  
J. Safrankova
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Bow Shock ◽  
Radial Dependence ◽  
Energetic Ions ◽  
Interplanetary Physics ◽  
Bow Shocks

Abstract. We present a case study of Geotail, Interball-1, IMP-8, and Wind observations of density and magnetic field strength cavities excavated by the enhanced pressures associated with bursts of energetic ions in the foreshock. Consistent with theoretical predictions, the pressure of the energetic ions diminishes rapidly with upstream distance due to a decrease in the flux of energetic ions and a transition from near-isotropic to streaming pitch angle distributions. Consequently, the cavities can only be observed immediately upstream from the bow shock. A comparison of conditions upstream from the pre- and post-noon bow shock demonstrates that foreshock cavities introduce perturbations into the oncoming solar wind flow with dimensions smaller than those of the magnetosphere. Dayside geosynchronous magnetic field strength variations observed by GOES-8 do not track the density variations seen by any of the spacecraft upstream from the bow shock in a one-to-one manner, indicating that none of these spacecraft observed the precise sequence of density variations that actually struck the subsolar magnetopause. Key words. Interplanetary physics (energetic particles; planetary bow shocks) – Magnetospheric physics (solar wind-magnetosphere interactions)

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