Found 8 entries in the Bibliography.

Showing entries from 1 through 8


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

Abstract 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 Versa ...

Wang, Dedong; Shprits, Yuri; Zhelavskaya, Irina; Effenberger, Frederic; Castillo, Angelica; Drozdov, Alexander; Aseev, Nikita; Cervantes, Sebastian;

YEAR: 2020     DOI: 10.1029/2019JA027422

Radiation belt; simulation; relativistic electrons; magnetopause shadowing; Wave-particle interaction; Plasmapause; Van Allen Probes


Storm Time Depletions of Multi-MeV Radiation Belt Electrons Observed at Different Pitch Angles

During geomagnetic storms, the rapid depletion of the high-energy (several MeV) outer radiation belt electrons is the result of loss to the interplanetary medium through the magnetopause, outward radial diffusion, and loss to the atmosphere due to wave-particle interactions. We have performed a statistical study of 110 storms using pitch angle resolved electron flux measurements from the Van Allen Probes mission and found that inside of the radiation belt (L* = 3 - 5) the number of storms that result in depletion of electron ...

. Y. Drozdov, A; Aseev, N.; Effenberger, F.; Turner, D.; Saikin, A.; . Y. Shprits, Y;

YEAR: 2019     DOI: 10.1029/2019JA027332

EMIC waves; multi-MeV electrons; Radiation belts; Van Allen Probes

Reanalysis of Ring Current Electron Phase Space Densities Using Van Allen Probe Observations, Convection Model, and Log-Normal Kalman Filter

Aseev, N.; . Y. Shprits, Y;

YEAR: 2019     DOI: 10.1029/2018SW002110

data assimilation; inner magnetosphere; Kalman Filter; Reanalysis; ring current; Van Allen Probes

Reanalysis of ring current electron phase space densities using Van Allen Probe observations, convection model, and log-normal Kalman filter

Models of ring current electron dynamics unavoidably contain uncertainties in boundary conditions, electric and magnetic fields, electron scattering rates, and plasmapause location. Model errors can accumulate with time and result in significant deviations of model predictions from observations. Data assimilation offers useful tools which can combine physics-based models and measurements to improve model predictions. In this study, we systematically analyze performance of the Kalman filter applied to a log-transformed convec ...

Aseev, N.A.; Shprits, Y.Y.;

YEAR: 2019     DOI: 10.1029/2018SW002110

data assimilation; inner magnetosphere; Kalman Filter; Reanalysis; ring current; Van Allen Probes

Electron intensity measurements by the Cluster/RAPID/IES instrument in Earth\textquoterights radiation belts and ring current

The Cluster mission, launched in 2000, has produced a large database of electron flux intensity measurements in the Earth\textquoterights magnetosphere by the Research with Adaptive Particle Imaging Detector (RAPID)/ Imaging Electron Spectrometer (IES) instrument. However, due to background contamination of the data with high-energy electrons (<400 keV) and inner-zone protons (230-630 keV) in the radiation belts and ring current, the data have been rarely used for inner-magnetospheric science. The current paper presents two ...

Smirnov, A.; Kronberg, E.; Latallerie, F.; Daly, P.; Aseev, N.; . Y. Shprits, Y; Kellerman, A.; Kasahara, S.; Turner, D.; Taylor, M.;

YEAR: 2019     DOI: 10.1029/2018SW001989

electrons; Radiation belts; Solar Cycle; Space weather; Van Allen Probes


Signatures of Ultrarelativistic Electron Loss in the Heart of the Outer Radiation Belt Measured by Van Allen Probes

Up until recently, signatures of the ultrarelativistic electron loss driven by electromagnetic ion cyclotron (EMIC) waves in the Earth\textquoterights outer radiation belt have been limited to direct or indirect measurements of electron precipitation or the narrowing of normalized pitch angle distributions in the heart of the belt. In this study, we demonstrate additional observational evidence of ultrarelativistic electron loss that can be driven by resonant interaction with EMIC waves. We analyzed the profiles derived from ...

Aseev, N.; . Y. Shprits, Y; . Y. Drozdov, A; Kellerman, A.; Usanova, M.; Wang, D.; Zhelavskaya, I.;

YEAR: 2017     DOI: 10.1002/2017JA024485

electron loss; EMIC waves; Radiation belts; ultrarelativistic electrons; Van Allen Probes; wave-particle interactions

EMIC wave parameterization in the long-term VERB code simulation

Electromagnetic ion cyclotron (EMIC) waves play an important role in the dynamics of ultrarelativistic electron population in the radiation belts. However, as EMIC waves are very sporadic, developing a parameterization of such wave properties is a challenging task. Currently, there are no dynamic, activity-dependent models of EMIC waves that can be used in the long-term (several months) simulations, which makes the quantitative modeling of the radiation belt dynamics incomplete. In this study, we investigate Kp, Dst, and AE ...

. Y. Drozdov, A; . Y. Shprits, Y; Usanova, M.; Aseev, N.; Kellerman, A.; Zhu, H.;

YEAR: 2017     DOI: 10.1002/2017JA024389

EMIC; Radiation belts; Van Allen Probes; VERB code

Dependence of radiation belt simulations to assumed radial diffusion rates tested for two empirical models of radial transport

Radial diffusion is one of the dominant physical mechanisms that drives acceleration and loss of the radiation belt electrons, which makes it very important for nowcasting and forecasting space weather models. We investigate the sensitivity of the two parameterizations of the radial diffusion of Brautigam and Albert (2000) and Ozeke et al. (2014) on long-term radiation belt modeling using the Versatile Electron Radiation Belt (VERB). Following Brautigam and Albert (2000) and Ozeke et al. (2014), we first perform 1-D radial d ...

. Y. Drozdov, A; . Y. Shprits, Y; Aseev, N.; Kellerman, A.; Reeves, G.;

YEAR: 2017     DOI: 10.1002/swe.v15.110.1002/2016SW001426

radial diffusion; Radiation belts; Van Allen Probes; VERB code