Biblio

Found 5 results
Filters: Author is Aseev, N. A.  [Clear All Filters]
2019
Authors: Smirnov A. G., Kronberg E. A., Latallerie F., Daly P. W., Aseev N. A., et al.
Title: Electron intensity measurements by the Cluster/RAPID/IES instrument in Earth's radiation belts and ring current
Abstract: The Cluster mission, launched in 2000, has produced a large database of electron flux intensity measurements in the Earth's 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 algorithms for background correction. The first algorithm is based on the empirical contamination percentages by both protons and electrons. The second algorithm uses simultaneous proton observations. The efficiencies of these algorithms are demonstrated by comparison of the . . .
Date: 02/2019 Publisher: Space Weather DOI: 10.1029/2018SW001989 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018SW001989
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Authors: Aseev N. A., and Shprits Y Y
Title: Reanalysis of Ring Current Electron Phase Space Densities Using Van Allen Probe Observations, Convection Model, and Log‐Normal Kalman Filter
Abstract: 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 convection model of ring current electrons and Van Allen Probe data. We consider long‐term dynamics of μ = 2.3 MeV/G and K = 0.3 G1/2RE electrons from 1 February 2013 to 16 June 2013. By using synthetic data, we show that the Kalman filter is capable of correcting . . .
Date: 04/2019 Publisher: Space Weather Pages: 619 - 638 DOI: 10.1029/2018SW002110 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018SW002110
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2017
Authors: Drozdov A. Y., Shprits Y Y, Aseev N. A., Kellerman A. C., and Reeves G D
Title: Dependence of radiation belt simulations to assumed radial diffusion rates tested for two empirical models of radial transport
Abstract: 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 diffusion simulations. Comparison of the simulation results with observations shows that the difference between simulations with either radial diffusion parameterization is small. To take into account effects of local acceleration and loss, we perform 3-D simulations, in. . .
Date: 01/2017 Publisher: Space Weather Pages: 150 - 162 DOI: 10.1002/swe.v15.110.1002/2016SW001426 Available at: http://onlinelibrary.wiley.com/doi/10.1002/2016SW001426/full
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Authors: Drozdov A. Y., Shprits Y Y, Usanova M. E., Aseev N. A., Kellerman A. C., et al.
Title: EMIC wave parameterization in the long-term VERB code simulation
Abstract: 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 indices, solar wind speed, and dynamic pressure as possible parameters of EMIC wave presence. The EMIC waves are included in the long-term simulations (1 year, including different geomagnetic activity) performed with the Versatile Electron Radiation Belt code, and we co. . .
Date: 08/2017 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2017JA024389 Available at: http://onlinelibrary.wiley.com/doi/10.1002/2017JA024389/full
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Authors: Aseev N. A., Shprits Y Y, Drozdov A. Y., Kellerman A. C., Usanova M. E., et al.
Title: Signatures of Ultrarelativistic Electron Loss in the Heart of the Outer Radiation Belt Measured by Van Allen Probes
Abstract: Up until recently, signatures of the ultrarelativistic electron loss driven by electromagnetic ion cyclotron (EMIC) waves in the Earth's 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 Van Allen Probe particle data as a function of time and three adiabatic invariants between 9 October and 29 November 2012. New local minimums in the profiles are accompanied by the narrowing of normalized pitch angle distributions and ground-based detection of EMIC waves. Such a cor. . .
Date: 09/2017 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2017JA024485 Available at: http://onlinelibrary.wiley.com/doi/10.1002/2017JA024485/full
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