scholarly journals The radial gradient of relativistic electrons at geosynchronous orbit

2004 ◽  
Vol 109 (A5) ◽  
Author(s):  
T. G. Onsager
Keyword(s):  
Geosynchronous Orbit ◽  
Relativistic Electrons ◽  
Radial Gradient

Effect of Interplanetary Disturbances and Geomagnetic Activities on Relativistic Electrons at Geosynchronous Orbit

2013 ◽  
Vol 56 (5) ◽  
pp. 532-545
Author(s):  
ZHANG Xiao-Fang ◽  
LIU Jun ◽  
WU Yao-Ping ◽  
ZHOU Lü ◽  
LIU Song-Tao
Keyword(s):  
Geosynchronous Orbit ◽  
Relativistic Electrons ◽  
Geomagnetic Activities

Relativistic electrons at geosynchronous orbit, interplanetary electron flux, and the 13-month Jovian synodic year

1989 ◽  
Vol 16 (10) ◽  
pp. 1129-1132 ◽  
Author(s):  
S. P. Christon ◽  
D. L. Chenette ◽  
D. N. Baker ◽  
D. Moses
Keyword(s):  
Electron Flux ◽  
Geosynchronous Orbit ◽  
Relativistic Electrons

An improved forecast system for relativistic electrons at geosynchronous orbit

Space Weather ◽  
2011 ◽  
Vol 9 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. L. Turner ◽  
X. Li ◽  
E. Burin des Roziers ◽  
S. Monk
Keyword(s):  
Geosynchronous Orbit ◽  
Relativistic Electrons ◽  
Forecast System

scholarly journals Average profiles of the solar wind and outer radiation belt during the extreme flux enhancement of relativistic electrons at geosynchronous orbit

2008 ◽  
Vol 26 (6) ◽  
pp. 1335-1339 ◽  
Author(s):  
R. Kataoka ◽  
Y. Miyoshi
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Radiation Belt ◽  
Dynamic Pressure ◽  
Recovery Phase ◽  
Geosynchronous Orbit ◽  
Relativistic Electrons ◽  
Outer Radiation Belt ◽  
Flux Enhancement ◽  
Solar Wind Structure

Abstract. We report average profiles of the solar wind and outer radiation belt during the extreme flux enhancement of relativistic electrons at geosynchronous orbit (GEO). It is found that seven of top ten extreme events at GEO during solar cycle 23 are associated with the magnetosphere inflation during the storm recovery phase as caused by the large-scale solar wind structure of very low dynamic pressure (<1.0 nPa) during rapid speed decrease from very high (>650 km/s) to typical (400–500 km/s) in a few days. For the seven events, the solar wind parameters, geomagnetic activity indices, and relativistic electron flux and geomagnetic field at GEO are superposed at the local noon period of GOES satellites to investigate the physical cause. The average profiles support the "double inflation" mechanism that the rarefaction of the solar wind and subsequent magnetosphere inflation are one of the best conditions to produce the extreme flux enhancement at GEO because of the excellent magnetic confinement of relativistic electrons by reducing the drift loss of trapped electrons at dayside magnetopause.

High-speed stream driven inferences of global wave distributions at geosynchronous orbit: relevance to radiation-belt dynamics

2010 ◽  
Vol 466 (2123) ◽  
pp. 3351-3362 ◽  
Author(s):  
Elizabeth A. MacDonald ◽  
Lauren W. Blum ◽  
S. Peter Gary ◽  
Michelle F. Thomsen ◽  
Michael H. Denton
Keyword(s):  
High Speed ◽  
Radiation Belt ◽  
Recovery Phase ◽  
Wave Activity ◽  
Geosynchronous Orbit ◽  
Relativistic Electrons ◽  
Particle Interactions ◽  
Early Recovery ◽  
Emic Wave ◽  
Major Loss

Three superposed epoch analyses of plasma data from geosynchronous orbit are compared to infer relative distributions of electromagnetic ion cyclotron (EMIC)- and whistler-mode wave instabilities. Both local-time and storm-time behaviours are studied with respect to dynamics of relativistic electrons. Using LANL-GEO particle data and a quasi-linear approximation for the wave growth allows us to estimate the instability of the two wave modes. This simple technique can allow powerful insights into wave–particle interactions at geosynchronous orbit. Whistler-wave activity peaks on the dayside during the early recovery phase and can continue to be above normal levels for several days. The main phase of all storms exhibits the most EMIC-wave activity, whereas in the recovery phase of the most radiation-belt-effective storms, a significantly suppressed level of EMIC activity is inferred. These key results indicate new dynamics relating to plasma delivery, source and response, but support generally accepted views of whistlers as a source process and EMIC-mode waves as a major loss contributor at geosynchronous orbit.

scholarly journals Features of energetic particle radial profiles inferred from geosynchronous responses to solar wind dynamic pressure enhancements

2009 ◽  
Vol 27 (2) ◽  
pp. 851-859 ◽  
Author(s):  
Y. Shi ◽  
E. Zesta ◽  
L. R. Lyons
Keyword(s):  
Magnetic Field ◽  
Phase Space ◽  
Dynamic Pressure ◽  
Radial Profile ◽  
Radial Distance ◽  
Geosynchronous Orbit ◽  
Relativistic Electrons ◽  
Phase Space Density ◽  
Space Density ◽  
Flux Response

Abstract. Determination of the radial profile of phase space density of relativistic electrons at constant adiabatic invariants is crucial for identifying the source for them within the outer radiation belt. The commonly used method is to convert flux observed at fixed energy to phase space density at constant first, second and third adiabatic invariants, which requires an empirical global magnetic field model and thus might produce some uncertainties in the final results. From a different perspective, in this paper we indirectly infer the shape of the radial profile of phase space density of relativistic electrons near the geosynchronous region by statistically examining the geosynchronous energetic flux response to 128 solar wind dynamic pressure enhancements during the years 2000 to 2003. We thus avoid the disadvantage of using empirical magnetic field models. Our results show that the flux response is species and energy dependent. For protons and low-energy electrons, the primary response to magnetospheric compression is an increase in flux at geosynchronous orbit. For relativistic electrons, the dominant response is a decrease in flux, which implies that the phase space density decreases toward increasing radial distance at geosynchronous orbit and leads to a local peak inside of geosynchronous orbit. The flux response of protons and non-relativistic electrons could result from a phase density that increases toward increasing radial distance, but this cannot be determined for sure due to the particle energization associated with pressure enhancements. Our results for relativistic electrons are consistent with previous results obtained using magnetic field models, thus providing additional confirmation that these results are correct and indicating that they are not the result of errors in their selected magnetic field model.

Which magnetic storms produce relativistic electrons at geosynchronous orbit?

2001 ◽  
Vol 106 (A8) ◽  
pp. 15533-15544 ◽  
Author(s):  
T. P. O'Brien ◽  
R. L. McPherron ◽  
D. Sornette ◽  
G. D. Reeves ◽  
R. Friedel ◽  
...  
Keyword(s):  
Magnetic Storms ◽  
Geosynchronous Orbit ◽  
Relativistic Electrons
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