scholarly journals A Comparative Study of ULF Waves' Role in the Dynamics of Charged Particles in the Plasmasphere: Van Allen Probes Observation

2018 ◽  
Vol 123 (7) ◽  
pp. 5334-5343 ◽  
Author(s):  
Jie Ren ◽  
Q. G. Zong ◽  
Y. Miyoshi ◽  
R. Rankin ◽  
H. E. Spence ◽  
...  
Keyword(s):  
Comparative Study ◽  
Charged Particles ◽  
Ulf Waves ◽  
Van Allen Probes

ULF waves and their influence on radiation belt dynamics in Earth's magnetosphere

2020 ◽  
Author(s):  
Robert Rankin ◽  
Alexander Degeling
Keyword(s):  
Radiation Belt ◽  
Geomagnetic Storms ◽  
Low Frequency ◽  
Recovery Phase ◽  
Ulf Waves ◽  
Wave Source ◽  
Initial Plasma ◽  
Plasma State ◽  
Van Allen Probes ◽  
Geomagnetic Fields

<p>Recent observations from the Van Allen Probes mission have established that Pc3-5 ultra-low-frequency (ULF) waves can energize ions and electrons via drift-resonance and drift-bounce resonance. The extent to which these waves contribute to the space weather of the belts is relatively poorly understood and requires sophisticated modelling and characterization of the dominant wave modes that arise in the development and recovery phase of geomagnetic storms. Despite more than four decades of observations and theoretical analysis of ULF waves, there is no framework for accurately assessing the global distribution of ULF waves and their influence on the ring current. <br>In this presentation, we describe a new global model of ULF waves that incorporates non-dipolar geomagnetic fields. The model is constrained using the GCPM of cold plasma density model and a specification of the ionosphere using the IRI and MSIS models. An algorithm is applied to adjust the initial plasma state to a quasi-static equilibrium that is then driven by a global convection electric field and ULF wave source. For specific observations by the Van Allen Probes and ARASE mission, the effect of these ULF waves on radiation belt ions and electrons is evaluated utilizing test-particle methodology and Liouville's theorem, which enables the phase space density to be followed and compared one-for-one with the satellite observations.  </p>

scholarly journals Comparative study of four reactions at onset of pre-equilibrium emission

2019 ◽  
Vol 223 ◽  
pp. 01010
Author(s):  
Magda Cicerchia ◽  
Fabiana Gramegna ◽  
Daniela Fabris ◽  
Tommaso Marchi ◽  
Marco Cinausero ◽  
...  
Keyword(s):  
Comparative Study ◽  
Nuclear Structure ◽  
Model Prediction ◽  
Reaction Mechanisms ◽  
Charged Particles ◽  
Decay Chain ◽  
Event Selection ◽  
Hot Nuclei ◽  
Light Charged Particles ◽  
Equilibrium Emission

The study of the emitted particles, comparing pre-equilibrium and thermal components, is a useful tool to examine the nuclear structure of emitters. Possible clustering effects, which may change the expected decay chain probability, could be highlighted on the competition between different reaction mechanisms. The NUCL-EX collaboration (INFN, Italy) has carried out an extensive research campaign on pre-equilibrium emission of light charged particles from hot nuclei. In this framework, the reactions 16O+30Si, 18O+28Si, 19F+27Al at 7 AMeV and 16O+30Si at 8 AMeV have been carried out using the GARFIELD+RCo array at Legnaro National Laboratories. Some anomalies in the α-particle emission channels have been evidenced in the measurement reported above, showing in an exclusive way the observed effects related to the entrance channels. The experimental results are compared to model prediction, for which the same filtering and complete event selection have been applied.

Storm time occurrence and spatial distribution of Pc4 poloidal ULF waves in the inner magnetosphere: A Van Allen Probes statistical study

2015 ◽  
Vol 120 (6) ◽  
pp. 4748-4762 ◽  
Author(s):  
Lei Dai ◽  
Kazue Takahashi ◽  
Robert Lysak ◽  
Chi Wang ◽  
John R. Wygant ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Statistical Study ◽  
Ulf Waves ◽  
Inner Magnetosphere ◽  
Van Allen Probes

Observations and simulations of electron flux oscillations in response to broadband ULF waves

2020 ◽  
Author(s):  
Xinlin Li ◽  
Theodoros Sarris ◽  
Michael Temerin ◽  
Hong Zhao ◽  
Leng Ying Khoo ◽  
...  
Keyword(s):  
Electron Flux ◽  
Low Frequency ◽  
Transport Processes ◽  
Ulf Waves ◽  
Magnetic Fluctuations ◽  
Radial Transport ◽  
Energy Channel ◽  
Van Allen Probes ◽  
Initial Results ◽  
Energy Channels

<p>It has recently been demonstrated through simulations and observations that flux oscillations of hundreds-keV electrons are produced in the magnetosphere in association with broadband Ultra Low Frequency (ULF) waves (Sarris et al., JGR, 2017). These oscillations are observed in the form of drift-periodic flux fluctuations, but are not associated with drift echoes following storm- or substorm-related energetic particle injections. They are observed in particular during quiet times, and it has been shown that they could indicate ongoing radial transport processes caused by ULF waves. It has also been shown that the width of electron energy channels is a critical parameter affecting the observed amplitude of flux oscillations, with narrower energy channel widths enabling the observation of higher-amplitude flux oscillations; this potentially explains why such features were not observed regularly before the Van Allen Probes era, as previous spacecraft generally had lower energy resolution. We extend these initial results by investigating the association between the observed flux oscillations with the amplitude of electric and magnetic fluctuations in the ULF range and with Phase Space Density gradients, both of which are expected to also affect radial transport rates.</p>

scholarly journals Externally driven plasmaspheric ULF waves observed by the Van Allen Probes

2015 ◽  
Vol 120 (1) ◽  
pp. 526-552 ◽  
Author(s):  
Kazue Takahashi ◽  
Richard E. Denton ◽  
William Kurth ◽  
Craig Kletzing ◽  
John Wygant ◽  
...  
Keyword(s):  
Ulf Waves ◽  
Van Allen Probes

scholarly journals Cold Plasmaspheric Electrons Affected by ULF Waves in the Inner Magnetosphere: A Van Allen Probes Statistical Study

2019 ◽  
Vol 124 (10) ◽  
pp. 7954-7965 ◽  
Author(s):  
Jie Ren ◽  
Q. G. Zong ◽  
X. Z. Zhou ◽  
H. E. Spence ◽  
H. O. Funsten ◽  
...  
Keyword(s):  
Statistical Study ◽  
Ulf Waves ◽  
Inner Magnetosphere ◽  
Van Allen Probes

Dynamics of the particle around de Sitter–Schwarzschild black hole surrounded by quintessence

2020 ◽  
Vol 35 (23) ◽  
pp. 2050130
Author(s):  
Israr Ali Khan ◽  
Amir Sultan Khan ◽  
Saeed Islam
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Dark Energy ◽  
Comparative Study ◽  
Effective Potential ◽  
Charged Particles ◽  
Particle Dynamics ◽  
Escape Velocity ◽  
De Sitter ◽  
Schwarzschild Black Hole

The study of particle dynamics in the vicinity of a black hole environed by dark energy and magnetic field has attracted researchers for their importance in astrophysics and cosmology. In this paper, we study the dynamics of neutral and charged particles in the vicinity of de Sitter–Schwarzschild black hole (DS–Sch-BH) surrounded by quintessence. The effect of the DS part is explored by virtue of effective potential, effective force, and escape velocity of the particle (neutral and charged) moving around DS–Sch-BH. Finally, a comparative study is also investigated.

Van Allen Probes observation of a 360° phase shift in the flux modulation of injected electrons by ULF waves

2017 ◽  
Author(s):  
X.-R. Chen ◽  
Q.-G. Zong ◽  
X.-Z. Zhou ◽  
J. Bernard Blake ◽  
J. R. Wygant ◽  
...  
Keyword(s):  
Phase Shift ◽  
Ulf Waves ◽  
Flux Modulation ◽  
Van Allen Probes

scholarly journals Interactions of energetic electrons with ULF waves triggered by interplanetary shock: Van Allen Probes observations in the magnetotail

2014 ◽  
Vol 119 (10) ◽  
pp. 8262-8273 ◽  
Author(s):  
Y. X. Hao ◽  
Q.-G. Zong ◽  
Y. F. Wang ◽  
X.-Z. Zhou ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Interplanetary Shock ◽  
Ulf Waves ◽  
Energetic Electrons ◽  
Van Allen Probes

Shock-induced radiation belt dynamics: Coordinated observations of drift echoes and ULF modulations in the dayside magnetosphere 

2021 ◽  
Author(s):  
Xingran Chen ◽  
Qiugang Zong ◽  
Ying Liu ◽  
Yixin Hao ◽  
Suiyan Fu ◽  
...  
Keyword(s):  
Radiation Belt ◽  
Interplanetary Shock ◽  
Observational Evidence ◽  
Ulf Waves ◽  
Outer Radiation Belt ◽  
Particle Measurements ◽  
Van Allen Probes ◽  
Characteristic Features ◽  
The One

<p>We employ conjunctive observations of particle fluxes and electromagnetic fields in the solar wind, magnetosheath, and dayside magnetosphere to investigate the radiation belt dynamics in response to the impingement of a fast forward interplanetary shock on 7 September 2017. Particularly, drift echoes associated with the one-kick acceleration caused by the shock-induced magnetosonic pulse and oscillations in the Pc 4 range associated with the azimuthally localized ULF waves are identified concurrently in the in-situ particle measurements obtained by the twin Van Allen Probes in the dayside outer radiation belt. Based on this observational evidence, we demonstrate that the radiation bet can be efficiently disturbed via the two mechanisms simultaneously by the shock arrival. We also depict the characteristic features to distinguish between the two mechanisms from an observational approach.</p>

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