scholarly journals Empirical model of lower band chorus wave distribution in the outer radiation belt

2015 ◽  
Vol 120 (12) ◽  
pp. 10,425-10,442 ◽  
Author(s):  
O. V. Agapitov ◽  
A. V. Artemyev ◽  
D. Mourenas ◽  
F. S. Mozer ◽  
V. Krasnoselskikh
2015 ◽  
Vol 33 (5) ◽  
pp. 583-597 ◽  
Author(s):  
H. Breuillard ◽  
O. Agapitov ◽  
A. Artemyev ◽  
E. A. Kronberg ◽  
S. E. Haaland ◽  
...  

Abstract. Chorus-type whistler waves are one of the most intense electromagnetic waves generated naturally in the magnetosphere. These waves have a substantial impact on the radiation belt dynamics as they are thought to contribute to electron acceleration and losses into the ionosphere through resonant wave–particle interaction. Our study is devoted to the determination of chorus wave power distribution on frequency in a wide range of magnetic latitudes, from 0 to 40°. We use 10 years of magnetic and electric field wave power measured by STAFF-SA onboard Cluster spacecraft to model the initial (equatorial) chorus wave spectral power, as well as PEACE and RAPID measurements to model the properties of energetic electrons (~ 0.1–100 keV) in the outer radiation belt. The dependence of this distribution upon latitude obtained from Cluster STAFF-SA is then consistently reproduced along a certain L-shell range (4 ≤ L ≤ 6.5), employing WHAMP-based ray tracing simulations in hot plasma within a realistic inner magnetospheric model. We show here that, as latitude increases, the chorus peak frequency is globally shifted towards lower frequencies. Making use of our simulations, the peak frequency variations can be explained mostly in terms of wave damping and amplification, but also cross-L propagation. These results are in good agreement with previous studies of chorus wave spectral extent using data from different spacecraft (Cluster, POLAR and THEMIS). The chorus peak frequency variations are then employed to calculate the pitch angle and energy diffusion rates, resulting in more effective pitch angle electron scattering (electron lifetime is halved) but less effective acceleration. These peak frequency parameters can thus be used to improve the accuracy of diffusion coefficient calculations.


2020 ◽  
Author(s):  
Yang Zhang ◽  
Binbin Ni ◽  
Xudong Gu ◽  
Yuri Shprits ◽  
Song Fu ◽  
...  

<p><span>Magnetospheric chorus is known to play a significant role in the acceleration and loss of radiation belt electrons. Interactions of chorus waves with radiation belt particles are commonly evaluated using quasi-linear diffusion codes that rely on statistical models, which might not accurately provide the instantaneous global wave distribution from limited in-situ wave measurements. Thus, a novel technique capable of inferring wave amplitudes from POES particle measurements, with an extensive coverage of L-shell and magnetic local time, has been established to obtain event-specific, global dynamic evolutions of chorus waves. This study, using 5 years of POES electron data, further improves the technique, and enables us to subsequently infer the chorus wave amplitudes for all useful data points (removing the electrons which were in the drift loss cone) and to construct the global distribution of lower-band chorus wave intensity. The results obtained from the improved technique reproduce Van Allen Probes in-situ observations of chorus waves reasonably well and reconstruct the major features of the global distribution of chorus waves. We demonstrate that such a data-based, dynamic model can provide near-real-time estimates of chorus wave intensity on a global scale for any time period when POES data are available, which cannot be obtained from in-situ wave measurements by equatorial satellites alone, but is crucial for quantifying the  dynamics of the radiation belt electrons.</span></p>


2021 ◽  
Vol 3 ◽  
pp. 67-76
Author(s):  
V. О. Barinova ◽  
◽  
V. V. Kalegaev ◽  

The paper deals with the quality assessment and the analysis of possible corrections of the empirical model of the shape and position of the high-latitude boundary of the Earth’s outer radiation belt [2] using the full dataset on the electron fluxes with energy above 100 keV measured in the recent 5 years at the orbit of the Meteor-M No. 2 satellite. The high-latitude boundary of the Earth’s outer radiation belt at the altitude of 800 km is approximated with an elliptic curve in the geomagnetic coordination system with the parameters depending on the universal time (UT effect) and geomagnetic activity (Dst index). The full dataset of intersections of the high-latitude boundary of the Earth’s outer radiation belt by the Meteor-M No. 2 satellite in 2014–2019 was constructed to test the model. The database was utilized to determine errors of the model for various geomagnetic conditions in the magnetosphere and at different magnetic longitudes and to propose ways for its modernization.


2018 ◽  
Vol 56 (1) ◽  
pp. 32-37 ◽  
Author(s):  
V. V. Kalegaev ◽  
W. O. Barinova ◽  
I. N. Myagkova ◽  
V. E. Eremeev ◽  
D. A. Parunakyan ◽  
...  

2014 ◽  
Vol 119 (3) ◽  
pp. 1693-1708 ◽  
Author(s):  
Yue Chen ◽  
Reiner H. W. Friedel ◽  
Michael G. Henderson ◽  
Seth G. Claudepierre ◽  
Steven K. Morley ◽  
...  

2007 ◽  
Vol 47 (6) ◽  
pp. 696-703 ◽  
Author(s):  
L. V. Tverskaya ◽  
E. A. Ginzburg ◽  
T. A. Ivanova ◽  
N. N. Pavlov ◽  
P. M. Svidsky

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