scholarly journals Differences in ground-observed chorus in geomagnetic storms with and without enhanced relativistic electron fluxes

2004 ◽  
Vol 109 (A11) ◽  
Author(s):  
A. J. Smith
Keyword(s):  
Relativistic Electron ◽  
Geomagnetic Storms

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 Recurrent geomagnetic storms and relativistic electron enhancements in the outer magnetosphere: ISTP coordinated measurements

1997 ◽  
Vol 102 (A7) ◽  
pp. 14141-14148 ◽  
Author(s):  
D. N. Baker ◽  
X. Li ◽  
N. Turner ◽  
J. H. Allen ◽  
L. F. Bargatze ◽  
...  
Keyword(s):  
Relativistic Electron ◽  
Geomagnetic Storms ◽  
Outer Magnetosphere

Formation of the Outer Radiation Belt during Geomagnetic Storms and the Adiabatic Mechanism of the Rise and Fall of Relativistic Electron Fluxes

2021 ◽  
Vol 85 (3) ◽  
pp. 309-313
Author(s):  
N. V. Sotnikov ◽  
E. E. Antonova ◽  
I. L. Ovchinnikov ◽  
V. G. Vorobjev ◽  
O. I. Yagodkina ◽  
...  
Keyword(s):  
Relativistic Electron ◽  
Radiation Belt ◽  
Geomagnetic Storms ◽  
Outer Radiation Belt

Characterization of relativistic electron flux rise times during the recovery phase of geomagnetic storms as measured by the NS41 GPS satellite

2008 ◽  
Vol 70 (14) ◽  
pp. 1745-1759 ◽  
Author(s):  
Athina Varotsou ◽  
Reiner H. Friedel ◽  
Geoff D. Reeves ◽  
Benoit Lavraud ◽  
Ruth M. Skoug ◽  
...  
Keyword(s):  
Relativistic Electron ◽  
Electron Flux ◽  
Geomagnetic Storms ◽  
Recovery Phase

scholarly journals Variability of Relativistic Electron Flux (E > 2 MeV) during Geo-Magnetically Quiet and Disturbed days: A Case Study

2020 ◽  
Author(s):  
Tulsi Thapa ◽  
Binod Adhikari ◽  
Prashrit Baruwal ◽  
Kiran Pudasainee
Keyword(s):  
Relativistic Electron ◽  
Geomagnetic Storm ◽  
Radiation Belt ◽  
Cross Correlation ◽  
Electron Flux ◽  
Geomagnetic Storms ◽  
Correlation Technique ◽  
Outer Radiation Belt ◽  
Cross Correlation Analysis ◽  
Intense Storm

Abstract. We analyzed the relativistic electron fluxes (E > 2 MeV) during three different geomagnetic storms: moderate, intense, and super-intense and one geo-magnetically quiet period. We have opted Continuous wavelet analysis and cross-correlation technique to extend current understanding and of the radiation-belt dynamics. We found that the fluctuation of relativistic electron fluxes dependent basically on prolonged southward interplanetary magnetic field IMF-Bz. Cross-correlation analysis depicted that SYM-H does not show a strong connection either with relativistic electron enhancement events or persistent depletion events. Our result supports the fact that geomagnetic storms are not a primary factor that pumps up the radiation belt. In fact they seem event specific; either depletion or enhancement or slight effect on the outer radiation belt might be observed depending on the event. Solar wind pressure and velocity were found to be highly and positively correlated with relativistic electron. We found that, the count of relativistic electron flux (> 2 MeV) decreases during the main phase of geomagnetic storm with the increase in – from quiet to super intense storm – geomagnetic storm conditions (Table 1). However, Psw was found to be weakly correlated in case of intense storms following an abrupt increase of electron flux for ~ 4 hrs, which is interesting and unique.

scholarly journals Neural network prediction of relativistic electrons at geosynchronous orbit during the storm recovery phase: effects of recurring substorms

2002 ◽  
Vol 20 (7) ◽  
pp. 947-951 ◽  
Author(s):  
M. Fukata ◽  
S. Taguchi ◽  
T. Okuzawa ◽  
T. Obara
Keyword(s):  
Neural Network ◽  
Relativistic Electron ◽  
Electron Flux ◽  
Geomagnetic Storms ◽  
Recovery Phase ◽  
Space Environment ◽  
Geosynchronous Orbit ◽  
Neural Network Models ◽  
Magnetospheric Configuration And Dynamics ◽  
Input Parameters

Abstract. During the recovery phase of geomagnetic storms, the flux of relativistic (>2 MeV) electrons at geosynchronous orbits is enhanced. This enhancement reaches a level that can cause devastating damage to instruments on satellites. To predict these temporal variations, we have developed neural network models that predict the flux for the period 1–12 h ahead. The electron-flux data obtained during storms, from the Space Environment Monitor on board a Geostationary Meteorological Satellite, were used to construct the model. Various combinations of the input parameters AL, SAL, Dst and SDst were tested (where S denotes the summation from the time of the minimum Dst). It was found that the model, including SAL as one of the input parameters, can provide some measure of relativistic electron-flux prediction at geosynchronous orbit during the recovery phase. We suggest from this result that the relativistic electron-flux enhancement during the recovery phase is associated with recurring substorms after Dst minimum and their accumulation effect.Key words. Magnetospheric physics (energetic particles, trapped; magnetospheric configuration and dynamics; storms and substorms)

scholarly journals Combined effects of concurrent Pc5 and chorus waves on relativistic electron dynamics

2015 ◽  
Vol 33 (9) ◽  
pp. 1173-1181 ◽  
Author(s):  
C. Katsavrias ◽  
I. A. Daglis ◽  
W. Li ◽  
S. Dimitrakoudis ◽  
M. Georgiou ◽  
...  
Keyword(s):  
Relativistic Electron ◽  
Geomagnetic Storms ◽  
Wave Activity ◽  
Electron Dynamics ◽  
Interplanetary Coronal Mass Ejections ◽  
Outer Radiation Belt ◽  
Outward Diffusion ◽  
Electron Population ◽  
Chorus Waves ◽  
Chorus Wave

Abstract. We present electron phase space density (PSD) calculations as well as concurrent Pc5 and chorus wave activity observations during two intense geomagnetic storms caused by interplanetary coronal mass ejections (ICMEs) resulting in contradicting net effect. We show that, during the 17 March 2013 storm, the coincident observation of chorus and relativistic electron enhancements suggests that the prolonged chorus wave activity seems to be responsible for the enhancement of the electron population in the outer radiation belt even in the presence of pronounced outward diffusion. On the other hand, the significant depletion of electrons, during the 12 September 2014 storm, coincides with long-lasting outward diffusion driven by the continuous enhanced Pc5 activity since chorus wave activity was limited both in space and time.

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