Analytical Chorus Wave Model Derived from Van Allen Probe Observations

Wang, Dedong; Shprits, Y. Y.; Zhelavskaya, Irina; Agapitov, Oleksiy; Drozdov, Alexander; Aseev, Nikita

doi:10.1029/2018ja026183

Cited by 55 publications

(92 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We note the statistical databases of chorus wave properties generated from the Van Allen Probes (Li et al, ), from Cluster (Agapitov et al, ), and the compilation from multiple satellites (DE1, Combined Release and Radiation Effects Satellite [CRRES], Cluster, Double Star TC1, and THEMIS) by Meredith et al (; Meredith, Horne, Li, et al, ). Wang et al () in this collection provide an analytical model of both amplitude and frequency for upper‐ and lower‐band chorus waves based on Van Allen Probes data (see also Zhu, Shprits, et al, , and Agapitov et al, ).…”

Section: Particle Loss In the Inner And Outer Zonesmentioning

confidence: 99%

Particle Dynamics in the Earth's Radiation Belts: Review of Current Research and Open Questions

et al. 2020

View full text Add to dashboard Cite

The past decade transformed our observational understanding of energetic particle processes in near‐Earth space. An unprecedented suite of observational systems was in operation including the Van Allen Probes, Arase, Magnetospheric Multiscale, Time History of Events and Macroscale Interactions during Substorms, Cluster, GPS, GOES, and Los Alamos National Laboratory‐GEO magnetospheric missions. They were supported by conjugate low‐altitude measurements on spacecraft, balloons, and ground‐based arrays. Together, these significantly improved our ability to determine and quantify the mechanisms that control the buildup and subsequent variability of energetic particle intensities in the inner magnetosphere. The high‐quality data from National Aeronautics and Space Administration's Van Allen Probes are the most comprehensive in situ measurements ever taken in the near‐Earth space radiation environment. These observations, coupled with recent advances in radiation belt theory and modeling, including dramatic increases in computational power, have ushered in a new era, perhaps a “golden era,” in radiation belt research. We have edited a Journal of Geophysical Research: Space Science Special Collection dedicated to Particle Dynamics in the Earth's Radiation Belts in which we gather the most recent scientific findings and understanding of this important region of geospace. This collection includes the results presented at the American Geophysical Union Chapman International Conference in Cascais, Portugal (March 2018) and many other recent and relevant contributions. The present article introduces and review the context, current research, and main questions that motivate modern radiation belt research divided into the following topics: (1) particle acceleration and transport, (2) particle loss, (3) the role of nonlinear processes, (4) new radiation belt modeling capabilities and the quantification of model uncertainties, and (5) laboratory plasma experiments.

show abstract

Section: Particle Loss In the Inner And Outer Zonesmentioning

confidence: 99%

Particle Dynamics in the Earth's Radiation Belts: Review of Current Research and Open Questions

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Charged particles that drift inward while conserving the first and second adiabatic invariants will increase their temperature anisotropy, which can result in an increased wave growth rate (Olson & Lee, 1983). Consequently, chorus waves are observed with greater abundance and intensity during geomagnetically active times (Oleksiy Agapitov et al, 2013;Kim et al, 2015;Meredith et al, 2001Meredith et al, , 2012D. Wang et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

The Storm Time Development of Source Electrons and Chorus Wave Activity During CME‐ and CIR‐Driven Storms

et al. 2019

View full text Add to dashboard Cite

Whistler mode chorus waves influence the dynamics of the Earth's radiation belts and the inner magnetosphere through gyroresonant wave particle interactions. Chorus waves are generated by anisotropic hot electrons from a few to tens of keV, called source electrons, which have increased access from the nightside plasma sheet to the inner magnetosphere during geomagnetic storms. The primary drivers of geomagnetic storms are coronal mass ejections (CMEs) and corotating interaction regions (CIRs). Through differences in their characteristic physical parameters, they can each impact the nightside plasma sheet differently. Using Van Allen Probes observations, we have conducted a superposed epoch analysis of chorus wave activity and source electron development across all local times between L = 2–6 during 25 CME‐ and 35 CIR‐driven storms. The superposed epoch analysis shows that chorus wave power follows the storm phase‐dependent access of the source electron population. Chorus waves and source electrons are observed on the dawnside during the main phase, when open drift path access via eastward convective drift from the plasma sheet is enhanced. During the recovery phase, chorus waves and source electrons are observed at all magnetic local times with low intensities, exemplifying the formation of a weak symmetric, trapped electron population. A linear theory approximation for wave growth from source electron observations shows that increased wave growth follows the enhanced source electrons during each storm phase. CME and CIR storms display similar behavior and levels of average wave power; however, chorus wave activity reaches lower L‐shells during CME storms on average.

show abstract

“…The calculation of the diffusion coefficients requires wave models depending on spatial variables, such as MLT, latitude, L , and geomagnetic conditions. For the amplitude and frequency distribution of chorus waves, we use a newly developed model based on 5 years of Van Allen Probe data (Wang et al, ). For the wave normal angle ( θ ) distribution of chorus waves, we use a frequently adopted model, that is, θ lc =0°, θ uc =45°, θ m =0°, and θ w =30°, where θ m is the peak value of wave normal angle, θ w is the width of the angle, and θ lc and θ uc are the lower and upper cut‐off to the wave normal angle distribution, outside which the wave power is zero (e.g., Kim et al, ; Thorne et al, ).…”

Section: Model Descriptionmentioning

confidence: 99%

“…In our simulations, we include the effect of magnetopause shadowing to investigate the reason for the sharp dropout before the enhancement event and test the influence of the different plasmapause positions. In addition, instead of using event‐specific chorus waves from observations, in our simulations, we use a statistical chorus wave model which was developed using 5 years of Van Allen Probe data (Wang et al, ). Figures 6b and 6c show the results of VERB‐3D simulations using different plasmapause positions.…”

Section: Comparison Of Simulations With Observationsmentioning

confidence: 99%

The Effect of Plasma Boundaries on the Dynamic Evolution of Relativistic Radiation Belt Electrons

et al. 2020

Self Cite

View full text Add to dashboard Cite

Understanding the dynamic evolution of relativistic electrons in the Earth's radiation belts during both storm and nonstorm times is a challenging task. The U.S. National Science Foundation's Geospace Environment Modeling (GEM) focus group "Quantitative Assessment of Radiation Belt Modeling" has selected two storm time and two nonstorm time events that occurred during the second year of the Van Allen Probes mission for in-depth study. Here, we perform simulations for these GEM challenge events using the 3D Versatile Electron Radiation Belt code. We set up the outer L * boundary using data from the Geostationary Operational Environmental Satellites and validate the simulation results against satellite observations from both the Geostationary Operational Environmental Satellites and Van Allen Probe missions for 0.9-MeV electrons. Our results show that the position of the plasmapause plays a significant role in the dynamic evolution of relativistic electrons. The magnetopause shadowing effect is included by using last closed drift shell, and it is shown to significantly contribute to the dropouts of relativistic electrons at high L * . We perform simulations using four different empirical radial diffusion coefficient models for the GEM challenge events, and the results show that these simulations reproduce the general dynamic evolution of relativistic radiation belt electrons. However, in the events shown here, simulations using the radial diffusion coefficients from Brautigam and Albert (2000) produce the best agreement with satellite observations. Key Points:• We investigate the effect of different plasmapause positions and radial diffusion coefficients during the four GEM challenge events • Including the magnetopause shadowing effect by using the last closed drift shell helps to reproduce the dropouts • The three-dimensional Versatile Electron Radiation Belt code reproduces the general dynamics of relativistic electrons during GEM challenge events Supporting Information:• Supporting Information S1 , et al. (2020). The effect of plasma boundaries on the dynamic evolution of relativistic radiation belt electrons.

show abstract

Analytical Chorus Wave Model Derived from Van Allen Probe Observations

Cited by 55 publications

References 89 publications

Particle Dynamics in the Earth's Radiation Belts: Review of Current Research and Open Questions

Particle Dynamics in the Earth's Radiation Belts: Review of Current Research and Open Questions

The Storm Time Development of Source Electrons and Chorus Wave Activity During CME‐ and CIR‐Driven Storms

The Effect of Plasma Boundaries on the Dynamic Evolution of Relativistic Radiation Belt Electrons

Contact Info

Product

Resources

About