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>

scholarly journals Magnetospheric Response to Solar Wind Forcing: ULF Wave – Particle Interaction Perspective

2021 ◽  
Author(s):  
Qiugang Zong
Keyword(s):  
Solar Wind ◽  
Radiation Belt ◽  
Ring Current ◽  
Dynamic Pressure ◽  
Plasma Heating ◽  
Interplanetary Shock ◽  
Wind Forcing ◽  
Ulf Waves ◽  
Radiation Belt Electrons ◽  
The Impact

Abstract. Solar wind forcing, e.g. interplanetary shock and/or solar wind dynamic pressure pulses impact on the Earth’s magnetosphere manifests many fundamental important space physics phenomena including producing electromagnetic waves, plasma heating and energetic particle acceleration. This paper summarizes our present understanding of the magnetospheric response to solar wind forcing in the aspects of radiation belt electrons, ring current ions and plasmaspheric plasma physics based on in situ spacecraft measurements, ground-based magnetometer data, MHD and kinetic simulations. Magnetosphere response to solar wind forcing, is not just a “one-kick” scenario. It is found that after the impact of solar wind forcing on the Earth’s magnetosphere, plasma heating and energetic particle acceleration started nearly immediately and could last for a few hours. Even a small dynamic pressure change of interplanetary shock or solar wind pressure pulse can play a non-negligible role in magnetospheric physics. The impact leads to generate series kind of waves including poloidal mode ultra-low frequency (ULF) waves. The fast acceleration of energetic electrons in the radiation belt and energetic ions in the ring current region response to the impact usually contains two contributing steps: (1) the initial adiabatic acceleration due to the magnetospheric compression; (2) followed by the wave-particle resonant acceleration dominated by global or localized poloidal ULF waves excited at various L-shells. Generalized theory of drift and drift-bounce resonance with growth or decay localized ULF waves has been developed to explain in situ spacecraft observations. The wave related observational features like distorted energy spectrum, boomerang and fishbone pitch angle distributions of radiation belt electrons, ring current ions and plasmaspheric plasma can be explained in the frame work of this generalized theory. It is worthy to point out here that poloidal ULF waves are much more efficient to accelerate and modulate electrons (fundamental mode) in the radiation belt and charged ions (second harmonic) in the ring current region. The results presented in this paper can be widely used in solar wind interacting with other planets such as Mercury, Jupiter, Saturn, Uranus and Neptune, and other astrophysical objects with magnetic fields.

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>

Solar wind compression induced ULF-modulation of whistler-mode waves in the deep inner magnetosphere

2021 ◽  
Author(s):  
Xiongjun Shang ◽  
Si Liu ◽  
Fuliang Xiao
Keyword(s):  
Solar Wind ◽  
Dynamic Pressure ◽  
Source Region ◽  
Rare Event ◽  
Periodic Pattern ◽  
Ulf Waves ◽  
Wave Source ◽  
Whistler Mode ◽  
Energetic Electrons ◽  
Whistler Mode Waves

<p>With observations of Van Allen Probes, we report a rare event of quasiperiodic whistler-mode waves in the dayside magnetosphere on 20 February 2014 as a response to the enhancement of solar wind dynamic pressure (P<sub>sw</sub>). The intensities of whistler-mode waves and anisotropy distributions of energetic electrons exhibit a ~5 mins quasi-periodic pattern, which is consistent with the period of synchronously observed compressional ULF waves. Based on the wave growth rates calculation, we suggest that the quasiperiodic whistler-mode waves could be generated by the energetic electrons with modulated anisotropy. The Poynting vectors of the whistler-mode waves alternate between northward and southward direction with a period twice the compressional ULF wave's near the equator, also exhibiting a clear modulated feature. This is probably because the intense ULF waves slightly altered the location of the local magnetic minimum, and thus modulated the relative direction of the wave source region respect to the spacecraft. Current results provide a direct evidence that the P<sub>sw</sub> play an important role in the generation and propagation of whistler-mode waves in the Earth's magnetosphere.</p>

Radial propagation of magnetospheric substorm-injected energetic electrons observed using a BD-IES instrument and Van Allen Probes

2016 ◽  
Vol 59 (7) ◽  
pp. 1508-1516 ◽  
Author(s):  
QiuGang Zong ◽  
YiXin Hao ◽  
Hong Zou ◽  
SuiYan Fu ◽  
XuZhi Zhou ◽  
...  
Keyword(s):  
Magnetospheric Substorm ◽  
Energetic Electrons ◽  
Van Allen Probes ◽  
Radial Propagation

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

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

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>

Sign in / Sign up

Export Citation Format

Share Document