scholarly journals Effect of electromagnetic ion cyclotron wave normal angle distribution on relativistic electron scattering in outer radiation belt

2007 ◽  
Vol 112 (A10) ◽  
pp. n/a-n/a ◽  
Author(s):  
G. V. Khazanov ◽  
K. V. Gamayunov
Keyword(s):  
Relativistic Electron ◽  
Electron Scattering ◽  
Radiation Belt ◽  
Angle Distribution ◽  
Outer Radiation Belt ◽  
Ion Cyclotron ◽  
Wave Normal ◽  
Normal Angle

On the effect of ULF waves on the outer radiation belt during geomagnetic storms

2021 ◽  
Author(s):  
Christopher Lara ◽  
Pablo S. Moya ◽  
Victor Pinto ◽  
Javier Silva ◽  
Beatriz Zenteno
Keyword(s):  
Relativistic Electron ◽  
Radiation Belt ◽  
Geomagnetic Storms ◽  
Cumulative Effect ◽  
Radiation Belts ◽  
Ulf Waves ◽  
Relativistic Electrons ◽  
Relative Role ◽  
Outer Radiation Belt ◽  
Ulf Wave

<p>The inner magnetosphere is a very important region to study, as with satellite-based communications increasing day after day, possible disruptions are especially relevant due to the possible consequences in our daily life. It is becoming very important to know how the radiation belts behave, especially during strong geomagnetic activity. The radiation belts response to geomagnetic storms and solar wind conditions is still not fully understood, as relativistic electron fluxes in the outer radiation belt can be depleted, enhanced or not affected following intense activity. Different studies show how these results vary in the face of different events. As one of the main mechanisms affecting the dynamics of the radiation belt are wave-particle interactions between relativistic electrons and ULF waves. In this work we perform a statistical study of the relationship between ULF wave power and relativistic electron fluxes in the outer radiation belt during several geomagnetic storms, by using magnetic field and particle fluxes data measured by the Van Allen Probes between 2012 and 2017. We evaluate the correlation between the changes in flux and the cumulative effect of ULF wave activity during the main and recovery phases of the storms for different position in the outer radiation belt and energy channels. Our results show that there is a good correlation between the presence of ULF waves and the changes in flux during the recovery phase of the storm and that correlations vary as a function of energy. Also, we can see in detail how the ULF power change for the electron flux at different L-shell We expect these results to be relevant for the understanding of the relative role of ULF waves in the enhancements and depletions of energetic electrons in the radiation belts for condition described.</p>

scholarly journals The relativistic electron response in the outer radiation belt during magnetic storms

2002 ◽  
Vol 20 (7) ◽  
pp. 957-965 ◽  
Author(s):  
R. H. A. Iles ◽  
A. N. Fazakerley ◽  
A. D. Johnstone ◽  
N. P. Meredith ◽  
P. Bühler
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Wind Speed ◽  
Interplanetary Magnetic Field ◽  
Relativistic Electron ◽  
Radiation Belt ◽  
Solar Wind Speed ◽  
Recovery Phase ◽  
Magnetic Storms ◽  
Outer Radiation Belt

Abstract. The relativistic electron response in the outer radiation belt during magnetic storms has been studied in relation to solar wind and geomagnetic parameters during the first six months of 1995, a period in which there were a number of recurrent fast solar wind streams. The relativistic electron population was measured by instruments on board the two microsatellites, STRV-1a and STRV-1b, which traversed the radiation belt four times per day from L ~ 1 out to L ~ 7 on highly elliptical, near-equatorial orbits. Variations in the E > 750 keV and E > 1 MeV electrons during the main phase and recovery phase of 17 magnetic storms have been compared with the solar wind speed, interplanetary magnetic field z-component, Bz , the solar wind dynamic pressure and Dst *. Three different types of electron responses are identified, with outcomes that strongly depend on the solar wind speed and interplanetary magnetic field orientation during the magnetic storm recovery phase. Observations also confirm that the L-shell, at which the peak enhancement in the electron count rate occurs has a dependence on Dst *.Key words. Magnetospheric physics (energetic particles, trapped; storms and substorms) – Space plasma physics (charged particle motion and accelerations)

scholarly journals Sensitivity of EMIC Wave‐Driven Scattering Loss of Ring Current Protons to Wave Normal Angle Distribution

2019 ◽  
Vol 46 (2) ◽  
pp. 590-598 ◽  
Author(s):  
Xing Cao ◽  
Binbin Ni ◽  
Danny Summers ◽  
Yuri Y. Shprits ◽  
Xudong Gu ◽  
...  
Keyword(s):  
Ring Current ◽  
Angle Distribution ◽  
Scattering Loss ◽  
Emic Wave ◽  
Wave Normal ◽  
Normal Angle

scholarly journals Electron Microbursts Induced by Nonducted Chorus Waves

2021 ◽  
Vol 8 ◽  
Author(s):  
Lunjin Chen ◽  
Xiao-Jia Zhang ◽  
Anton Artemyev ◽  
Liheng Zheng ◽  
Zhiyang Xia ◽  
...  
Keyword(s):  
Field Line ◽  
Particle Simulation ◽  
Electron Precipitation ◽  
Outer Radiation Belt ◽  
Energetic Electrons ◽  
Chorus Waves ◽  
Wave Normal ◽  
Intense Electron ◽  
The Magnetic Field ◽  
Normal Angle

Microbursts, short-lived but intense electron precipitation observed by low-Earth-orbiting satellites, may contribute significantly to the losses of energetic electrons in the outer radiation belt. Their origin is likely due to whistler mode chorus waves, as evidenced by a strong overlap in spatial correlation of the two. Despite previous efforts on modeling bursty electron precipitation induced by chorus waves, most, if not all, rely on the assumption that chorus waves are ducted along the field line with zero wave normal angle. Such ducting is limited to cases when fine-scale plasma density irregularities are present. In contrast, chorus waves propagate in a nonducted way in plasmas with smoothly varying density, allowing wave normals to gradually refract away from the magnetic field line. In this study, the interaction of ducted and nonducted chorus waves with energetic electrons is investigated using test particle simulation. Substantial differences in electron transport are found between the two different scenarios, and resultant electron precipitation patterns are compared. Such a comparison is valuable for interpreting low Earth-orbiting satellite observations of electron flux variation in response to the interaction with magnetospheric chorus waves.

On the semi-annual variation of relativistic electrons in the outer radiation belt

2021 ◽  
Author(s):  
Sigiava Aminalragia-Giamini ◽  
Christos Katsavrias ◽  
Constantinos Papadimitriou ◽  
Ioannis A. Daglis ◽  
Ingmar Sandberg ◽  
...  
Keyword(s):  
Relativistic Electron ◽  
Radiation Belt ◽  
Annual Variation ◽  
European Space Agency ◽  
Phase Relationship ◽  
Radiation Environment ◽  
Relativistic Electrons ◽  
Solar Cycles ◽  
Outer Radiation Belt ◽  
Horizon 2020

<p>The nature of the semi-annual variation in the relativistic electron fluxes in the Earth’s outer radiation belt is investigated using Van Allen Probes (MagEIS and REPT) and GOES (EPS) data during solar cycle 24. We perform wavelet and cross-wavelet analysis in a broad energy and spatial range of electron fluxes and examine their phase relationship with the axial, equinoctial and Russell-McPherron mechanisms. It is found that the semi-annual variation in the relativistic electron fluxes exhibits pronounced power in the 0.3 – 4.2 MeV energy range at L-shells higher than 3.5 and, moreover, it exhibits an in-phase relationship with the Russell-McPherron effect indicating the former is primarily driven by the latter. Furthermore, the analysis of the past 3 solar cycles with GOES/EPS indicates that the semi-annual variation at geosynchronous orbit is evident during the descending phases and coincides with periods of a higher (lower) HSS (ICME) occurrence.</p><p>This work has received funding from the European Union's Horizon 2020 research and innovation programme “SafeSpace” under grant agreement No 870437 and from the European Space Agency under the “European Contribution to International Radiation Environment Near Earth (IRENE) Modelling System” activity under ESA Contract No 4000127282/19/NL/IB/gg.</p>

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