Bibliography



Found 11 entries in the Bibliography.


Showing entries from 1 through 11


2019

Global Empirical Picture of Magnetospheric Substorms Inferred From Multimission Magnetometer Data

Magnetospheric substorms represent key explosive processes in the interaction of the Earth\textquoterights magnetosphere with the solar wind, and their understanding and modeling are critical for space weather forecasting. During substorms, the magnetic field on the nightside is first stretched in the antisunward direction and then it rapidly contracts earthward bringing hot plasmas from the distant space regions into the inner magnetosphere, where they contribute to geomagnetic storms and Joule dissipation in the polar iono ...

Stephens, G.; Sitnov, M.; Korth, H.; Tsyganenko, N.; Ohtani, S.; Gkioulidou, M.; . Y. Ukhorskiy, A;

YEAR: 2019     DOI: 10.1029/2018JA025843

Current sheet thinning; Data-mining; Magnetotail dipolarization; Storm-substorm relationship; substorm current wedge; substorms; Van Allen Probes

2018

Ion Trapping and Acceleration at Dipolarization Fronts: High-Resolution MHD/Test-Particle Simulations

Much of plasma heating and transport from the magnetotail into the inner magnetosphere occurs in the form of mesoscale discrete injections associated with sharp dipolarizations of magnetic field (dipolarization fronts). In this paper we investigate the role of magnetic trapping in acceleration and transport of the plasmasheet ions into the ring current. For this purpose we use high-resolution global MHD and three-dimensional test-particle simulations. It is shown that trapping, produced by sharp magnetic field gradients at t ...

. Y. Ukhorskiy, A; Sorathia, K.; Merkin, V.; Sitnov, M.; Mitchell, D.; Gkioulidou, M.;

YEAR: 2018     DOI: 10.1029/2018JA025370

injections; plasma pressure; ring current; trapping; Van Allen Probes

2017

Ion acceleration at dipolarization fronts in the inner magnetosphere

During geomagnetic storms plasma pressure in the inner magnetosphere is controlled by energetic ions of tens to hundreds of keV. Plasma pressure is the source of global storm time currents, which control the distribution of magnetic field and couple the inner magnetosphere and the ionosphere. Recent analysis showed that the buildup of hot ion population in the inner magnetosphere largely occurs in the form of localized discrete injections associated with sharp dipolarizations of magnetic field, similar to dipolarization fron ...

. Y. Ukhorskiy, A; Sitnov, M.; Merkin, V.; Gkioulidou, M.; Mitchell, D.;

YEAR: 2017     DOI: 10.1002/2016JA023304

injections; ring current; trapping; Van Allen Probes

Acceleration at Dipolarization Fronts in the Inner Magnetosphere

During geomagnetic storms plasma pressure in the inner magnetosphere is controlled by energetic ions of tens to hundreds keV. Plasma pressure is the source of global storm-time currents, which control the distribution of magnetic field and couple the inner magnetosphere and the ionosphere. Recent analysis showed that the buildup of hot ion population in the inner magnetosphere largely occurs in the form of localized discrete injections associated with sharp dipolarizations of magnetic field, similar to dipolarization fronts ...

. Y. Ukhorskiy, A; Sitnov, M.; Merkin, V.; Gkioulidou, M.; Mitchell, D.;

YEAR: 2017     DOI: 10.1002/2016ja023304

injections; ring current; trapping; Van Allen Probes

2015

Global Storm-Time Depletion of the Outer Electron Belt

The outer radiation belt consists of relativistic (>0.5 MeV) electrons trapped on closed trajectories around Earth where the magnetic field is nearly dipolar. During increased geomagnetic activity, electron intensities in the belt can vary by ordersof magnitude at different spatial and temporal scale. The main phase of geomagnetic storms often produces deep depletions of electron intensities over broad regions of the outer belt. Previous studies identified three possible processes that can contribute to the main-phase deplet ...

. Y. Ukhorskiy, A; Sitnov, M.; Millan, R.; Kress, B.; Fennell, J.; Claudepierre, S.; Barnes, R.;

YEAR: 2015     DOI: 10.1002/2014JA020645

dropout; Geomagnetic storms; magnetopause loss; Radial Transport; Radiation belt; ring current; Van Allen Probes

Empirical modeling of the storm-time innermost magnetosphere using Van Allen Probes and THEMIS data: Eastward and banana currents

The structure of storm-time currents in the inner magnetosphere, including its innermost region inside 4RE, is studied for the first time using a modification of the empirical geomagnetic field model TS07D and new data from Van Allen Probes and THEMIS missions. It is shown that the model, which uses basis-function expansions instead of ad hoc current modules to approximate the magnetic field, consistently improves its resolution and magnetic field reconstruction with the increase of the number of basis functions and resolves ...

Stephens, G.; Sitnov, M.; . Y. Ukhorskiy, A; Roelof, E.; Tsyganenko, N.; Le, G.;

YEAR: 2015     DOI: 10.1002/2015JA021700

eastward current; empirical geomagnetic field; magnetic storm; ring current; Van Allen Probes

2014

Rotationally driven 'zebra stripes' in Earth's inner radiation belt

Structured features on top of nominally smooth distributions of radiation-belt particles at Earth have been previously associated with particle acceleration and transport mechanisms powered exclusively by enhanced solar-wind activity1, 2, 3, 4. Although planetary rotation is considered to be important for particle acceleration at Jupiter and Saturn5, 6, 7, 8, 9, the electric field produced in the inner magnetosphere by Earth\textquoterights rotation can change the velocity of trapped particles by only about 1\textendash2 kil ...

. Y. Ukhorskiy, A; Sitnov, M.; Mitchell, D.; Takahashi, K; Lanzerotti, L.; Mauk, B.;

YEAR: 2014     DOI: 10.1038/nature13046

Magnetospheric physics; Van Allen Probes

2013

Dynamics of Radiation Belt Particles

This paper reviews basic concepts of particle dynamics underlying theoretical aspect of radiation belt modeling and data analysis. We outline the theory of adiabatic invariants of quasiperiodic Hamiltonian systems and derive the invariants of particle motion trapped in the radiation belts. We discuss how the nonlinearity of resonant interaction of particles with small-amplitude plasma waves, ubiquitous across the inner magnetosphere, can make particle motion stochastic. Long-term evolution of a stochastic system can be descr ...

. Y. Ukhorskiy, A; Sitnov, M.;

YEAR: 2013     DOI: 10.1007/s11214-012-9938-5

RBSP; Van Allen Probes

Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE)

The Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) on the two Van Allen Probes spacecraft is the magnetosphere ring current instrument that will provide data for answering the three over-arching questions for the Van Allen Probes Program: RBSPICE will determine \textquotedbllefthow space weather creates the storm-time ring current around Earth, how that ring current supplies and supports the creation of the radiation belt populations,\textquotedblright and how the ring current is involved in radiation belt ...

Mitchell, D.; Lanzerotti, L.; Kim, C.; Stokes, M.; Ho, G.; Cooper, S.; UKHORSKIY, A; Manweiler, J.; Jaskulek, S.; Haggerty, D.; Brandt, P.; SITNOV, M; Keika, K.; Hayes, J.; Brown, L.; Gurnee, R.; Hutcheson, J.; Nelson, K.; Paschalidis, N.; Rossano, E.; Kerem, S.;

YEAR: 2013     DOI: 10.1007/s11214-013-9965-x

RBSP; Van Allen Probes

Rapid acceleration of protons upstream of earthward propagating dipolarization fronts

[1] Transport and acceleration of ions in the magnetotail largely occurs in the form of discrete impulsive events associated with a steep increase of the tail magnetic field normal to the neutral plane (Bz), which are referred to as dipolarization fronts. The goal of this paper is to investigate how protons initially located upstream of earthward moving fronts are accelerated at their encounter. According to our analytical analysis and simplified two-dimensional test-particle simulations of equatorially mirroring particles, ...

. Y. Ukhorskiy, A; Sitnov, M.; Merkin, V.; Artemyev, A.;

YEAR: 2013     DOI: 10.1002/jgra.50452

RBSP; Van Allen Probes

2008

Radial transport in the outer radiation belt due to global magnetospheric compressions

Earth\textquoterights outer radiation belt is populated by relativistic electrons that produce a complex dynamical response to varying geomagnetic activity. One fundamental process defining global state of the belt is radial transport of electrons across their drift shells. Radial transport is induced by resonant interaction of electron drift motion with ULF oscillations of electric and magnetic fields and is commonly believed to be a diffusive process. The goal of this paper is the analysis of radial transport due to typica ...

UKHORSKIY, A; SITNOV, M;

YEAR: 2008     DOI: 10.1016/j.jastp.2008.07.018

Radial Transport



  1