scholarly journals Statistical pitch angle properties of substorm-injected electron clouds and their relation to dawnside energetic electron precipitation

2005 ◽  
Vol 110 (A5) ◽  
Author(s):  
A. Åsnes
Keyword(s):  
Pitch Angle ◽  
Energetic Electron ◽  
Electron Precipitation ◽  
Electron Clouds

scholarly journals Comparison between CNA and energetic electron precipitation: simultaneous observation by Poker Flat Imaging Riometer and NOAA satellite

2005 ◽  
Vol 23 (5) ◽  
pp. 1555-1563 ◽  
Author(s):  
Y.-M. Tanaka ◽  
M. Ishii ◽  
Y. Murayama ◽  
M. Kubota ◽  
H. Mori ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Electron Flux ◽  
Energetic Electron ◽  
Energetic Particles ◽  
Electron Precipitation ◽  
Angle Distribution ◽  
Pitch Angle Distribution ◽  
Loss Cone ◽  
Isotropic Pitch ◽  
Trapped Electron

Abstract. The cosmic noise absorption (CNA) is compared with the precipitating electron flux for 19 events observed in the morning sector, using the high-resolution data obtained during the conjugate observations with the imaging riometer at Poker Flat Research Range (PFRR; 65.11° N, 147.42° W), Alaska, and the low-altitude satellite, NOAA 12. We estimate the CNA, using the precipitating electron flux measured by NOAA 12, based on a theoretical model assuming an isotropic pitch angle distribution, and quantitatively compare them with the observed CNA. Focusing on the eight events with a range of variation larger than 0.4dB, three events show high correlation between the observed and estimated CNA (correlation coefficient (r0)>0.7) and five events show low correlation (r0<0.5). The estimated CNA is often smaller than the observed CNA (72% of all data for 19 events), which appears to be the main reason for the low-correlation events. We examine the assumption of isotropic pitch angle distribution by using the trapped electron flux measured at 80° zenith angle. It is shown that the CNA estimated from the trapped electron flux, assuming an isotropic pitch angle distribution, is highly correlated with the observed CNA and is often overestimated (87% of all data). The underestimate (overestimate) of CNA derived from the precipitating (trapped) electron flux can be interpreted in terms of the anisotropic pitch angle distribution similar to the loss cone distribution. These results indicate that the CNA observed with the riometer may be quantitatively explained with a model based on energetic electron precipitation, provided that the pitch angle distribution and the loss cone angle of the electrons are taken into account. Keywords. Energetic particles, precipitating – Energetic particles, trapped – Ionosphere-magnetosphere interactions

Statistical Distribution of Energetic Electron Precipitation due to Hiss Waves In the Earth’s Inner Magnetosphere

2021 ◽  
Author(s):  
Qianli Ma
Keyword(s):  
Energy Flux ◽  
Pitch Angle ◽  
Energetic Electron ◽  
Statistical Distribution ◽  
Electron Precipitation ◽  
Characteristic Energy ◽  
Loss Cone ◽  
Inner Magnetosphere ◽  
The Earth ◽  
Chorus Waves

&lt;p&gt;We investigate the statistical distribution of energetic electron precipitation from the equatorial magnetosphere due to hiss waves in the plasmasphere and plumes. Using Van Allen Probes measurements, we calculate the pitch angle diffusion coefficients at the pitch angle of bounce loss cone, and evaluate the energy spectrum of precipitating electron flux using quasi-linear theory. Our ~6.5 years survey shows that, during disturbed times, the plasmaspheric hiss mostly causes the electron precipitation at L &gt; 3 near the dayside in the plasmasphere, and hiss waves in plume cause the precipitation at L &gt; 5 near dayside and L &gt; 3.5 near the dusk side. The precipitating energy flux increases with increasing geomagnetic index, and is typically higher in the plasmaspheric plume than the plasmasphere. The characteristic energy of precipitation increases from ~20 keV at L = 6 to ~100 keV at L = 3, potentially causing the loss of electrons at several hundred keV. Although the total precipitating energy flux due to hiss waves is generally lower than the precipitation due to whistler mode chorus waves, the characteristic energy of precipitation due to hiss is higher, and the precipitation extends closer to the Earth.&lt;/p&gt;

Energetic Electron Pitch Angle Distributions During the Cassini Final Orbits

2018 ◽  
Vol 45 (7) ◽  
pp. 2911-2917 ◽  
Author(s):  
J. F. Carbary ◽  
D. G. Mitchell ◽  
P. Kollmann ◽  
N. Krupp ◽  
E. Roussos ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Energetic Electron

scholarly journals Strong localized variations of the low-altitude energetic electron fluxes in the evening sector near the plasmapause

1998 ◽  
Vol 16 (1) ◽  
pp. 25-33 ◽  
Author(s):  
E. E. Titova ◽  
T. A. Yahnina ◽  
A. G. Yahnin ◽  
B. B. Gvozdevsky ◽  
A. A. Lyubchich ◽  
...  
Keyword(s):  
Sharp Increase ◽  
Electron Flux ◽  
Particle Interaction ◽  
Energetic Electron ◽  
Recovery Phase ◽  
Electron Precipitation ◽  
Statistical Characteristics ◽  
Evening Sector ◽  
Proton Precipitation ◽  
Low Altitude

Abstract. Specific type of energetic electron precipitation accompanied by a sharp increase in trapped energetic electron flux are found in the data obtained from low-altitude NOAA satellites. These strongly localized variations of the trapped and precipitated energetic electron flux have been observed in the evening sector near the plasmapause during recovery phase of magnetic storms. Statistical characteristics of these structures as well as the results of comparison with proton precipitation are described. We demonstrate the spatial coincidence of localized electron precipitation with cold plasma gradient and whistler wave intensification measured on board the DE-1 and Aureol-3 satellites. A simultaneous localized sharp increase in both trapped and precipitating electron flux could be a result of significant pitch-angle isotropization of drifting electrons due to their interaction via cyclotron instability with the region of sharp increase in background plasma density.Key words. Ionosphere (particle precipitation; wave-particle interaction) Magnetospheric Physics (plasmasphere)

scholarly journals ULF modulation of energetic electron precipitation observed by VLF/LF radio propagation

2020 ◽  
Vol 2020 (372) ◽  
pp. 29-40
Author(s):  
Takuya Miyashita ◽  
Hiroyo Ohya ◽  
Fuminori Tsuchiya ◽  
Asuka Hirai ◽  
Mitsunori Ozaki ◽  
...  
Keyword(s):  
Energetic Electron ◽  
Electron Precipitation ◽  
Radio Propagation

scholarly journals The effect of energetic electron precipitation on middle mesospheric night-time ozone during and after a moderate geomagnetic storm

2012 ◽  
Vol 39 (21) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. Daae ◽  
P. Espy ◽  
H. Nesse Tyssøy ◽  
D. Newnham ◽  
J. Stadsnes ◽  
...  
Keyword(s):  
Geomagnetic Storm ◽  
Energetic Electron ◽  
Electron Precipitation ◽  
Night Time

Maintenance of the middle-latitude nocturnal D-layer by energetic electron precipitation

1976 ◽  
Vol 114 (4) ◽  
pp. 497-508 ◽  
Author(s):  
Walther N. Spjeldvik ◽  
Richard M. Thorne
Keyword(s):  
Energetic Electron ◽  
Middle Latitude ◽  
Electron Precipitation

scholarly journals Pitch angle scattering of an energetic magnetized particle by a circularly polarized electromagnetic wave

2021 ◽  
Author(s):  
Paul M. Bellan
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Wave ◽  
Kinetic Energy ◽  
Potential Energy ◽  
Pitch Angle ◽  
Energetic Electron ◽  
Circularly Polarized ◽  
Angle Scattering ◽  
Background Magnetic Field ◽  
Pseudo Potential

&lt;p&gt;The interaction between a circularly polarized electromagnetic wave and an energetic gyrating particle is described [1] using a relativistic pseudo-potential that is a function of the frequency mismatch,&amp;#160; a measure of the extent to which &amp;#969;-k&lt;sub&gt;z&lt;/sub&gt;v&lt;sub&gt;z&lt;/sub&gt;=&amp;#937;/&amp;#947; is not true. The description of this wave-particle interaction involves a sequence of relativistic transformations that ultimately demonstrate that the pseudo potential energy of a pseudo particle adds to a pseudo kinetic energy giving a total pseudo energy that is a constant of the motion. The pseudo kinetic energy is proportional to the square of the particle acceleration (compare to normal kinetic energy which is the square of a velocity) and the pseudo potential energy is a function of the mismatch and so effectively a function of the particle velocity parallel to the background magnetic field (compare to normal potential energy which is a function of position). Analysis of the pseudo-potential provides a means for interpreting particle motion in the wave in a manner analogous to the analysis of a normal particle bouncing in a conventional potential well.&amp;#160; The wave-particle&amp;#160; interaction is electromagnetic and so differs from and is more complicated than the well-known Landau damping of electrostatic waves.&amp;#160; The pseudo-potential profile depends on the initial mismatch, the normalized wave amplitude, and the initial angle between the wave magnetic field and the particle perpendicular velocity. For zero initial mismatch, the pseudo-potential consists of only one valley, but for finite mismatch, there can be two valleys separated by a hill. A large pitch angle scattering of the energetic electron can occur in the two-valley situation but fast scattering can also occur in a single valley. Examples relevant to magnetospheric whistler waves are discussed. Extension to the situation of a distribution of relativistic particles is presented in a companion talk [2].&lt;/p&gt;&lt;p&gt;[1] P. M. Bellan, Phys. Plasmas 20, Art. No. 042117 (2013)&lt;/p&gt;&lt;p&gt;[2] Y. D. Yoon and P. M. Bellan, JGR 125, Art. No. e2020JA027796 (2020)&lt;/p&gt;

scholarly journals New conjunctive CubeSat and balloon measurements to quantify rapid energetic electron precipitation

2013 ◽  
Vol 40 (22) ◽  
pp. 5833-5837 ◽  
Author(s):  
L. W. Blum ◽  
Q. Schiller ◽  
X. Li ◽  
R. Millan ◽  
A. Halford ◽  
...  
Keyword(s):  
Energetic Electron ◽  
Electron Precipitation ◽  
Balloon Measurements
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