scholarly journals Dynamic theory of relativistic electrons stochastic heating by whistler mode waves with application to the Earth magnetosphere

2008 ◽  
Vol 113 (A3) ◽  
pp. n/a-n/a ◽  
Author(s):  
G. V. Khazanov ◽  
A. A. Tel'nikhin ◽  
T. K. Kronberg
Keyword(s):  
Dynamic Theory ◽  
Relativistic Electrons ◽  
Whistler Mode ◽  
Stochastic Heating ◽  
The Earth ◽  
Whistler Mode Waves

Electron Pitch Angle Distributions in the Compressional Pc5 Waves

2021 ◽  
Author(s):  
Xiao Ma ◽  
Anmin Tian ◽  
Quanqi Shi ◽  
Shichen Bai ◽  
Ji Liu ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Interaction Effects ◽  
Plasma Pressure ◽  
Whistler Waves ◽  
Whistler Mode ◽  
Compressional Waves ◽  
The Earth ◽  
Pressure Anisotropy ◽  
Electron Distributions ◽  
Whistler Mode Waves

<p>In the two flanks of the Earth’s magnetosphere, the compressional Pc5 waves are often observed. Previous study suggests that these waves are usually excited by plasma pressure anisotropy such as drift mirror instability. Interestingly, whistler mode waves are often observed in the magnetic trough regions of the compressional Pc5 waves. In this study, we use 10 years (2007-2016) THEMIS A data to study the electron distributions in the compressional Pc5 waves associated with the whistler mode waves. We find three typical electron pitch angle distributions (PADs) in these compressional waves: cigar-shape, donut-shape and pancake-shape. They predominantly occur at tens to hundreds eV, several keV and >10 keV, respectively. The interaction effects between the electrons and whistler waves inside the magnetic troughs are stressed in understanding the formation of these PADs.</p>

On the upper frequency limit of whistler mode waves observed by low-altitude spacecraft

2020 ◽  
Author(s):  
Frantisek Nemec ◽  
Ondřej Santolík ◽  
Michel Parrot
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Waves ◽  
Low Frequency ◽  
Realistic Model ◽  
Wave Intensity ◽  
Frequency Limit ◽  
Whistler Mode ◽  
The Earth ◽  
Whistler Mode Waves ◽  
Low Altitude

<p>Frequency-latitude plots of electromagnetic wave intensity in the very low frequency range (VLF, up to about 20 kHz) observed by the low altitude DEMETER spacecraft are analyzed. Apart from electromagnetic waves generated by plasma instabilities in the magnetosphere, a significant portion of the detected wave intensity comes from ground-based lightning activity and VLF military transmitters. These whistler mode waves are observed not only close to source locations, but also close to their geomagnetically conjugated points. There appears to be an upper frequency limit of such emissions, where the wave intensity substantially decreases. Its frequency roughly corresponds to half of the equatorial electron cyclotron frequency at a respective magnetic field line, suggesting a relation to wave ducting in ducts with enhanced density. However, it seems to exhibit a non-negligible longitudinal dependence and it is different during the day than during the night. We use a realistic model of the Earth’s magnetic field to explain the observed variations. We interpret the observations in terms of ducted/unducted wave propagation, and we compare the wave intensities in the source hemisphere with those measured in the hemisphere geomagnetically conjugated.</p>

scholarly journals Radial variation of whistler-mode chorus: first results from the STAFF/DWP instrument on board the Double Star TC-1 spacecraft

2005 ◽  
Vol 23 (8) ◽  
pp. 2937-2942 ◽  
Author(s):  
O. Santolík ◽  
E. Macúšová ◽  
K. H. Yearby ◽  
N. Cornilleau-Wehrlin ◽  
H. StC. K. Alleyne
Keyword(s):  
Cyclotron Frequency ◽  
Power Spectra ◽  
Double Star ◽  
Electron Cyclotron ◽  
Radial Variation ◽  
Whistler Mode ◽  
Electron Cyclotron Frequency ◽  
The Earth ◽  
First Results ◽  
Initial Results

Abstract. We use the first measurements of the STAFF/DWP instrument on the Double Star TC-1 spacecraft to investigate whistler-mode chorus. We present initial results of a systematic study on radial variation of dawn chorus. The chorus events show an increased intensity at L parameter above 6. This is important for the possible explanation of intensifications of chorus, which were previously observed closer to the Earth at higher latitudes. Our results also indicate that the upper band of chorus at frequencies above one-half of the electron cyclotron frequency disappears for L above 8. The lower band of chorus is observed at frequencies below 0.4 of the electron cyclotron frequency up to L of 11-12. The maxima of the chorus power spectra are found at slightly lower frequencies compared to previous studies. We do not observe any distinct evolution of the position of the chorus frequency band as a function of L. More data of the TC-1 spacecraft are needed to verify these initial results and to increase the MLT coverage.

scholarly journals Radio waves and whistler-mode waves in solar wind and their interactions with energetic electrons

2020 ◽  
Author(s):  
Cynthia Cattell ◽  
Aaron Breneman ◽  
Lindsay Glesener ◽  
Ben Leiran ◽  
Ben Short ◽  
...  
Keyword(s):  
Solar Wind ◽  
Radio Waves ◽  
Whistler Mode ◽  
Energetic Electrons ◽  
Whistler Mode Waves
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