Energetic electron precipitation during a magnetospheric substorm and its relationship to wave particle interaction

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)

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Anomalous electron precipitation near the Earth’s auroral zone induced by the wave–particle interaction

Physics of Plasmas ◽

10.1063/1.872390 ◽

1997 ◽

Vol 4 (6) ◽

pp. 2269-2275 ◽

Cited By ~ 1

Author(s):

I. F. Potapenko ◽

A. G. Elfimov ◽

A. S. de Assis ◽

C. A. de Azevedo

Keyword(s):

Particle Interaction ◽

Auroral Zone ◽

Electron Precipitation ◽

Wave Particle Interaction

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Pi2-pulsations observed in energetic electron precipitation and magnetic field in association with a substorm surge

Annales Geophysicae ◽

10.5194/angeo-22-2097-2004 ◽

2004 ◽

Vol 22 (6) ◽

pp. 2097-2105 ◽

Cited By ~ 3

Author(s):

A. Åsnes ◽

J. Stadsnes ◽

J. Bjordal ◽

N. Østgaard ◽

D. L. Detrick ◽

...

Keyword(s):

Magnetic Field ◽

Particle Interaction ◽

Energetic Electron ◽

Global Scale ◽

Electron Precipitation ◽

High Temporal Resolution ◽

Expansion Phase ◽

Multiple Observations ◽

Pi2 Pulsations ◽

Polar Satellite

Abstract. For a substorm 24 July 1998 PIXIE observes the onset and expansion during a perigee pass of the Polar satellite. This gives an opportunity to follow the evolution of the onset and expansion phase, almost on a global scale with relatively high temporal resolution. The substorm is presented with multiple observations throughout the magnetosphere. Following the onset of the substorm we observe a localised region of modulated energetic electron fluxes following the passage of the westward travelling surge in the pre-midnight region. We count at least six clear pulses with a period of approximately one minute. Concurrent magnetic ground measurements show similar characteristics, almost simultaneously with the pulses in precipitation. We propose several possible mechanism for the pulsations, amongst them the theory of modulated wave particle interaction first proposed by coroniti70.

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Fluctuation of Lower Ionosphere Associated with Energetic Electron Precipitations during a Substorm

Atmosphere ◽

10.3390/atmos12050573 ◽

2021 ◽

Vol 12 (5) ◽

pp. 573

Author(s):

Tongxing Fu ◽

Zhixu Wu ◽

Peng Hu ◽

Xin Zhang

Keyword(s):

Radio Wave ◽

Current Sheet ◽

Geomagnetic Storm ◽

Particle Interaction ◽

Energetic Electron ◽

Lower Ionosphere ◽

Electron Precipitation ◽

Electron Interaction ◽

Energetic Electrons ◽

Tail Current

In this paper, using the combined observations of the NOAA 16, LANL-01A, IMAGE satellites, VLF radio wave, and ground-based riometers, we study the fluctuation of lower ionosphere-associated precipitating energetic electrons during a geomagnetic storm on 8 November 2004. Associated with the substorm dispersion injection observed by the LANL-01A satellite, the riometers observed obvious enhancements of ionospheric absorption within the electron isotropic zone, which they attributed to the tail current sheet scattering (TCS) mechanism. Through observations of the NOAA 16 satellite, we found a sharp enhancement of the precipitating electron flux within the anisotropic zone, which entailed an obvious separation of energetic electron precipitation at high latitudes. This energetic electron precipitation within the anisotropic zone leads to the significant enhancement of electron density in the D region, thus resulting in the variations of VLF radio wave amplitudes, which propagate in the middle latitudes. Since the projection of the electron precipitation region within the anisotropic zone is at the inner edge of the plasmapause observed by the IMAGE EUV, the precipitation of energetic electrons should be attributed to the ELF hiss-ring current electron interaction. As a result, the energetic electron precipitations due to the tail current sheet scattering mechanism and wave-particle interaction in the inner magnetosphere were both observed and analyzed as they were associated with a substorm during a geomagnetic storm.

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The Predictive Capabilities of the Auroral Electrojet Index for Medium Energy Electron Precipitation

Frontiers in Astronomy and Space Sciences ◽

10.3389/fspas.2021.714146 ◽

2021 ◽

Vol 8 ◽

Author(s):

H. Nesse Tyssøy ◽

N. Partamies ◽

E. M. Babu ◽

C. Smith-Johnsen ◽

J. A. Salice

Keyword(s):

Decadal Variability ◽

Particle Interaction ◽

Energetic Electron ◽

High Energy ◽

Energy Electron ◽

Electron Precipitation ◽

Medium Energy ◽

Ae Index ◽

High Energy Tail ◽

Potential Link

The chemical imprint of the energetic electron precipitation on the atmosphere is now acknowledged as a part of the natural forcing of the climate system. It has, however, been questioned to which degree current proxies are able to quantify the medium energy electron (MEE) (≳30 keV) precipitation and the associated daily and decadal variability. It is particularly challenging to model the high energy tail (≳300 keV) of MEE, both in terms of the intensity as well as the timing. This study explores the predictive capabilities of the AE index for the MEE precipitation. MEE measurements from the NOAA/POES over a full solar cycle from 2004 to 2014 are applied. We combine observations from the MEPED 0° and 90° detectors together with theory of pitch angle diffusion by wave-particle interaction to estimate the precipitating fluxes. To explore the energy dependent time scales, each of the MEPED energy channels, > 43, >114, and >292 keV are evaluated independently. While there is a strong correlation between the daily resolved AE index and >43 keV fluxes, it is a poor predictor for the >292 keV fluxes. We create new AE based MEE proxies by accumulating the AE activity over multiple days, including terms counting for the associated lifetimes. The results indicate that AE based proxies can predict at least 70% of the observed MEE precipitation variance at all energies. The potential link between the AE index, substorms and the MEE precipitation is discussed.

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Significance of Wave-Particle Interaction Analyzer for direct measurements of nonlinear wave-particle interactions

Annales Geophysicae ◽

10.5194/angeo-31-503-2013 ◽

2013 ◽

Vol 31 (3) ◽

pp. 503-512 ◽

Cited By ~ 16

Author(s):

Y. Katoh ◽

M. Kitahara ◽

H. Kojima ◽

Y. Omura ◽

S. Kasahara ◽

...

Keyword(s):

Kinetic Energy ◽

Velocity Vector ◽

Statistical Significance ◽

Particle Interaction ◽

Energetic Electron ◽

Particle Interactions ◽

Whistler Mode ◽

Wave Particle Interaction ◽

Energetic Electrons ◽

Wave Particle Interactions

Abstract. In the upcoming JAXA/ERG satellite mission, Wave Particle Interaction Analyzer (WPIA) will be installed as an onboard software function. We study the statistical significance of the WPIA for measurement of the energy transfer process between energetic electrons and whistler-mode chorus emissions in the Earth's inner magnetosphere. The WPIA measures a relative phase angle between the wave vector E and velocity vector v of each electron and computes their inner product W, where W is the time variation of the kinetic energy of energetic electrons interacting with plasma waves. We evaluate the feasibility by applying the WPIA analysis to the simulation results of whistler-mode chorus generation. We compute W using both a wave electric field vector observed at a fixed point in the simulation system and a velocity vector of each energetic electron passing through this point. By summing up Wi of an individual particle i to give Wint, we obtain significant values of Wint as expected from the evolution of chorus emissions in the simulation result. We can discuss the efficiency of the energy exchange through wave-particle interactions by selecting the range of the kinetic energy and pitch angle of the electrons used in the computation of Wint. The statistical significance of the obtained Wint is evaluated by calculating the standard deviation σW of Wint. In the results of the analysis, positive or negative Wint is obtained at the different regions of velocity phase space, while at the specific regions the obtained Wint values are significantly greater than σW, indicating efficient wave-particle interactions. The present study demonstrates the feasibility of using the WPIA, which will be on board the upcoming ERG satellite, for direct measurement of wave-particle interactions.

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