Found 5 entries in the Bibliography.

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Improving empirical magnetic field models by fitting to in situ data using an optimized parameter approach

A method for comparing and optimizing the accuracy of empirical magnetic field models using in situ magnetic field measurements is presented. The optimization method minimizes a cost function - τ - that explicitly includes both a magnitude and an angular term. A time span of 21 days, including periods of mild and intense geomagnetic activity, was used for this analysis. A comparison between five magnetic field models (T96, T01S, T02, TS04, TS07) widely used by the community demonstrated that the T02 model was, on average, t ...

Brito, Thiago; Morley, Steven;

YEAR: 2017     DOI: 10.1002/2017SW001702

comparison; Empirical Model; magnetic field model; optimization; Van Allen Probes


Simulation of ULF wave modulated radiation belt electron precipitation during the 17 March 2013 storm

Balloon-borne instruments detecting radiation belt precipitation frequently observe oscillations in the mHz frequency range. Balloons measuring electron precipitation near the poles in the 100 keV to 2.5 MeV energy range, including the MAXIS, MINIS, and most recently the BARREL balloon experiments, have observed this modulation at ULF wave frequencies [e.g. Foat et al., 1998; Millan et al., 2002; Millan, 2011]. Although ULF waves in the magnetosphere are seldom directly linked to increases in electron precipitation since the ...

Brito, T.; Hudson, M.; Kress, B.; Paral, J.; Halford, A.; Millan, R.; Usanova, M.;

YEAR: 2015     DOI: 10.1002/2014JA020838

precipitation; Radiation belts; Ulf; ULF modulation


Precipitation and energization of relativistic radiation belt electrons induced by ULF oscillations in the magnetosphere

There is a renewed interest in the study of the radiation belts with the recent launch of the Van Allen Probes satellites. The mechanisms that drive the global response of the radiation belts to geomagnetic storms are not yet well understood. Global simulations using magnetohydrodynamics (MHD) model fields as drivers provide a valuable tool for studying the dynamics of these MeV energetic particles. ACE satellite measurements of the MHD solar wind parameters are used as the upstream boundary condition for the Lyon-Fedder-Mob ...

Brito, Thiago;

YEAR: 2014     DOI:

0373:Geophysics; 0607:Electromagnetics; 0725:Atmospheric sciences; Atmospheric sciences; Earth sciences; Electromagnetics; Energization; Geophysics; precipitation; Pure sciences; Radiation belts; Ulf


Energetic radiation belt electron precipitation showing ULF modulation

1] The energization and loss processes for energetic radiation belt electrons are not yet well understood. Ultra Low Frequency (ULF) waves have been correlated with both enhancement in outer zone radiation belt electron flux and modulation of precipitation loss to the atmosphere. This study considers the effects of ULF waves in the Pc-4 to Pc-5 period range (45 s\textendash600 s) on electron loss to the atmosphere on a time scale of several minutes. Global simulations using magnetohydrodynamics (MHD) model fields as drivers ...

Brito, T.; Woodger, L.; Hudson, M.; MILLAN, R;

YEAR: 2012     DOI: 10.1029/2012GL053790

Charged particle motion and acceleration; Energetic particles: precipitating; Radiation belts; wave-particle interactions

Radiation belt 2D and 3D simulations for CIR-driven storms during Carrington Rotation 2068

As part of the International Heliospheric Year, the Whole Heliosphere Interval, Carrington Rotation 2068, from March 20 to April 16, 2008 was chosen as an internationally coordinated observing and modeling campaign. A pair of solar wind structures identified as Corotating Interaction Regions (CIR), characteristic of the declining phase of the solar cycle and solar minimum, was identified in solar wind plasma measurements from the ACE satellite. Such structures have previously been determined to be geoeffective in producing e ...

Hudson, M.; Brito, Thiago; Elkington, Scot; Kress, Brian; Li, Zhao; Wiltberger, Mike;

YEAR: 2012     DOI: 10.1016/j.jastp.2012.03.017

Magnetosphere; Modeling; Radiation belts; Solar wind