Controlled precipitation of energetic Van Allen belt protons by electromagnetic ion cyclotron (EMIC) waves

Space Weather ◽  
2014 ◽  
Vol 12 (6) ◽  
pp. 354-367 ◽  
Author(s):  
M. de Soria-Santacruz ◽  
M. Martinez-Sanchez ◽  
Y. Y. Shprits
Keyword(s):  
Ion Cyclotron ◽  
Controlled Precipitation ◽  
Emic Waves

scholarly journals Simultaneous Observations of Electromagnetic Ion Cyclotron (EMIC) Waves and Pitch Angle Scattering During a Van Allen Probes Conjunction

2020 ◽  
Vol 125 (4) ◽  
Author(s):  
K. Sigsbee ◽  
C. A. Kletzing ◽  
J. B. Faden ◽  
A. N. Jaynes ◽  
G. D. Reeves ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Angle Scattering ◽  
Van Allen Probes ◽  
Ion Cyclotron ◽  
Emic Waves

Observations of simultaneously occurring ULF and Ion Cyclotron Waves by the GOES-16 satellite magnetometer and particle detectors at geostationary orbit

2020 ◽  
Author(s):  
Paul Loto'aniu
Keyword(s):  
Magnetic Field ◽  
Ring Current ◽  
Resonance Condition ◽  
Sampling Rate ◽  
Ion Fluxes ◽  
Ulf Waves ◽  
Ulf Wave ◽  
Ion Cyclotron ◽  
Generation Mechanisms ◽  
Emic Waves

<p>The GOES-16 spacecraft, launched in November 2016, is the first of the GOES-R series next generation NOAA weather satellites. The spacecraft has a similar suite of space weather instruments to previous GOES satellites but with improved magnetometer sampling rate and wider energy range of particle flux observations. Presented are observations of simultaneously occurring Pc 4/5 ULF waves and electromagnetic ion cyclotron (EMIC) waves with a discussion on the relationship between the two wave modes including possible generation mechanisms. The waves were also observed in the particle data and we discuss both adiabatic and non-adiabatic wave-particle effects. Relativistic electron fluxes showed strong adiabatic motion with the magnetic field ULF waves. Estimates of Pc 4/5 ULF wave m-numbers suggest they were high, while ring current energy ion fluxes showed ULF variations with non-zero phasing relative to magnetic field ULF wave. This suggests ULF wave drift resonance with ring current ions. In one event we observed EMIC variations in the ion fluxes around energies that can drift resonate with simultaneously observed Pc 5 waves, suggesting that one particle population may be responsible for generating and/or modifying both observed Pc 5 and EMIC waves. ULF variations were also observed in electron/ion fluxes at lower energies down to 30 eV. We looked into ULF bounce resonance with 30 eV electrons, but the resonance condition did not match the observations. We will also discuss future plans to expand this study of ULF waves and wave-particle interactions using the two newest GOES satellites.</p>

scholarly journals Ring Current Proton Dynamics Driven by Wave-Particle Interactions During a Nonstorm Period

2021 ◽  
pp. 98-104
Author(s):  
Sergei V. Smolin
Keyword(s):  
Pitch Angle ◽  
Ring Current ◽  
Activity Index ◽  
Proton Flux ◽  
Angle Distribution ◽  
Particle Interactions ◽  
Pitch Angle Distribution ◽  
Ion Cyclotron ◽  
Wave Particle Interactions ◽  
Emic Waves

Modeling of pitch angle scattering of ring current protons at interaction with electromagnetic ion cyclotron waves during a nonstorm period was considered very seldom. Therefore it is used correlated observation of enhanced electromagnetic ion cyclotron (EMIC) waves and dynamic evolution of ring current proton flux collected by Cluster satellite near the location L = 4.5 during March 26–27, 2003, a nonstorm period (Dst > –10 nT). Energetic (5–30 keV) proton fluxes are found to drop rapidly (e.g., a half hour) at lower pitch angles, corresponding to intensified EMIC wave activities. As mathematical model is used the non-stationary one-dimensional pitch angle diffusion equation which allows to compute numerically density of phase space or pitch angle distribution of the charged particles in the Earth’s magnetosphere. The model depends on time t, a local pitch angle and several parameters (the mass of a particle, the energy, the McIlwain parameter, the magnetic local time or geomagnetic eastern longitude, the geomagnetic activity index, parameter of the charged particle pitch angle distribution taken for the 90 degrees pitch angle at t = 0, the lifetime due to wave–particle interactions). This model allows numerically to estimate also for different geophysical conditions a lifetime due to wave–particle interactions. It is shown, that EMIC waves can yield decrements in proton flux within 30 minutes, consistent with the observational data. The good consent is received. Comparison of results on full model for the pitch angle range from 0 up to 180 degrees and on the model for the 90 degrees pitch angle is lead. For a perpendicular differential flux of the Earth’s ring current protons very good consent with the maximal relative error approximately 3.23 % is received

scholarly journals Energy Exchange Between Electromagnetic Ion Cyclotron (EMIC) Waves and Thermal Plasma: From Theory to Observations

2021 ◽  
Vol 8 ◽  
Author(s):  
M. E. Usanova
Keyword(s):  
Thermal Plasma ◽  
Ring Current ◽  
Plasma Heating ◽  
Particle Interactions ◽  
Ion Heating ◽  
Thermal Electron ◽  
Plasma Species ◽  
Ion Cyclotron ◽  
Radiation Belt Electrons ◽  
Emic Waves

The cold plasmaspheric plasma, the ring current and the radiation belts constitute three important populations of the inner magnetosphere. The overlap region between these populations gives rise to wave-particle interactions between different plasma species and wave modes observed in the magnetosphere, in particular, electromagnetic ion cyclotron (EMIC) waves. These waves can resonantly interact with multiple particle species, being an important loss process for both ring current ions and radiation belt electrons, as well as a cold plasma heating mechanism. This mini-review will focus on the interaction between EMIC waves and cold and thermal plasma, specifically the role of EMIC waves in cold and thermal electron and ion heating. It will discuss early theoretical results in conjunction with numerical modelling and recent satellite observations, and address outstanding problems and controversies in this field.

scholarly journals On the Impacts of Ions of Ionospheric Origin and Their Composition on Magnetospheric EMIC Waves

2021 ◽  
Vol 8 ◽  
Author(s):  
Justin H. Lee ◽  
Lauren W. Blum ◽  
Lunjin Chen
Keyword(s):  
Wave Generation ◽  
Magnetospheric Plasma ◽  
Large Numbers ◽  
Emic Wave ◽  
Direct Measurements ◽  
Ion Cyclotron ◽  
Earth's Magnetosphere ◽  
Ion Species ◽  
Emic Waves

Large numbers of theory and observation studies have been conducted on electromagnetic ion cyclotron (EMIC) waves occurring in Earth’s magnetosphere. Numerous studies have shown that accurately specifying the ions of ionospheric origin and their composition can greatly improve understanding of magnetospheric EMIC waves, specifically their generation, their properties, and their effects on the magnetospheric plasma populations. With the launch and operations of multiple recent missions carrying plasma instrumentation capable of acquiring direct measurements of multiple ion species, we use this opportunity to review recent magnetospheric EMIC wave efforts utilizing these new assets, with particular focus on the role of ions of ionospheric origin in wave generation, propagation, and interaction with particles. The review of progress leads us to a discussion of the unresolved questions to be investigated using future modeling capabilities or when new missions or instrumentation capabilities are developed.

Electromagnetic ion-cyclotron instability in low beta plasma with intrinsic Alfven waves

2021 ◽  
Author(s):  
GuanShan Pu ◽  
ChuanBing Wang ◽  
PeiJin Zhang ◽  
Lin Ye
Keyword(s):  
Growth Rate ◽  
Low Frequency ◽  
Alfven Waves ◽  
Qualitative Description ◽  
Alfvén Waves ◽  
Temperature Anisotropy ◽  
Dimensional Parameter ◽  
Positive Effects ◽  
Ion Cyclotron ◽  
Emic Waves

<p>Intrinsic Alfven waves (IAWs) exist pervasively in the solar-terrestrial plasma, which can preferentially heat newborn ions in the direction perpendicular to the ambient magnetic field via non-resonant interactions when the plasma beta is low. The anisotropized newborn ion populations can excite electromagnetic ion-cyclotron (EMIC) instability. Parametric calculations indicate that the lower the plasma beta is, the higher the growth rate, while the growth rate increases with the number density of newborn ions and the intensity of IAWs. The marginal stable surface in three-dimensional parameter space is also calculated, which provides a qualitative description of parametric conditions for instability. We propose that the coupled effects of non-resonant heating by IAWs and EMIC instability could be an effective mechanism for transferring the energy from low-frequency IAWs to EMIC waves with a frequency below the gyrofrequency of the corresponding ion species. Furthermore, the temperature anisotropy of background ions with the same sense has positive effects on the growth of EMIC waves excited by newborn ions.</p>

Direct Observational Evidence of the Simultaneous Excitation of Electromagnetic Ion Cyclotron Waves and Magnetosonic Waves by an Anisotropic Proton Ring Distribution

2021 ◽  
Author(s):  
Shangchun Teng ◽  
Nigang Liu ◽  
Qianli Ma ◽  
Xin Tao ◽  
Wen Li
Keyword(s):  
Energetic Electron ◽  
Observational Evidence ◽  
Ion Dynamics ◽  
Frequency Spectra ◽  
Simultaneous Excitation ◽  
Proton Distribution ◽  
Ion Cyclotron ◽  
Electromagnetic Ion Cyclotron Waves ◽  
Generation Mechanisms ◽  
Emic Waves

<p>Magnetosonic (MS) waves and electromagnetic ion cyclotron (EMIC) waves are two important plasma wave modes in the magnetosphere. Previous simulations have shown that both waves could be generated by a ring-like proton distribution, while direct observational evidence has yet to be reported. Here, we present simultaneous observations of MS and EMIC waves and a detailed case analysis. The linear growth rates estimated for both waves are in good agreement with the observed wave frequency spectra. The measured proton distribution evolution is also compared with the simulation results, providing direct observational evidence for the previous theoretical prediction that anisotropic ring-like proton distributions could excite MS and EMIC waves simultaneously. Our findings are crucial for understanding the generation mechanisms of and relation between MS and EMIC waves and for evaluating their combined effects on energetic electron and ion dynamics. </p>

scholarly journals The nonlinear coupling of electromagnetic ion cyclotron and lower hybrid waves in the ring current region: the magnetic storm 1-7May 1998

2004 ◽  
Vol 11 (2) ◽  
pp. 229-239 ◽  
Author(s):  
G. V. Khazanov ◽  
E. N. Krivorutsky ◽  
K. V. Gamayunov ◽  
L. A. Avanov
Keyword(s):  
Electric Fields ◽  
Ring Current ◽  
Kinetic Equations ◽  
Global Scale ◽  
Lower Hybrid ◽  
Ion Cyclotron ◽  
Hybrid Waves ◽  
Mass Dependent ◽  
Lower Hybrid Waves ◽  
Emic Waves

Abstract. The excitation of lower hybrid waves (LHWs) is a widely discussed mechanism of interaction between plasma species in space, and is one of the unresolved questions of magnetospheric multi-ion plasmas. In this paper we present the morphology, dynamics, and level of LHW activity generated by electromagnetic ion cyclotron (EMIC) waves during the 2-7 May 1998 storm period on the global scale. The LHWs were calculated based on a newly developed self-consistent model (Khazanov et. al., 2002) that couples the system of two kinetic equations: one equation describes the ring current (RC) ion dynamic, and another equation describes the evolution of EMIC waves. It is found that the LHWs are excited by helium ions due to their mass dependent drift in the electric field of EMIC waves. The level of LHW activity is calculated assuming that the induced scattering process is the main saturation mechanism for these waves. The calculated LHWs electric fields are consistent with the observational data.

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