Simulation of proton radiation belt formation during the March 24, 1991 SSC

Hudson, M. K.; Kotelnikov, Alexei D.; Li, X.; Roth, I.; Temerin, M.; Wygant, J. R.; Blake, J. B.; Gussenhoven, M. S.

doi:10.1029/95gl00009

Cited by 102 publications

(69 citation statements)

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“…The results of the simulation reproduced the observation (see Figure 1b) and explained the mechanism of shock-induced radial transport and energization of electrons. Later, Hudson et al [1995] successfully used the same model to reproduce the observed sudden proton enhancement. Elkington et al [2002] ran a guiding-center electron simulation of the event using MHD model fields, resulting in a peak in the energy spectrum at about 13 MeV around L = 3.…”

Section: Introductionmentioning

confidence: 99%

Parametric study of shock‐induced transport and energization of relativistic electrons in the magnetosphere

Gannon¹,

Li²,

Temerin³

2005

J. Geophys. Res.

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[1] The sudden appearance of a new radiation belt consisting of electrons with energies greater than 13 MeV near 2.5 Earth radii (R E ), was observed by CRRES (Combined Radiation and Release Experiment Satellite) on 24 March 1991. Li et al. (1993) showed that the cause was an electromagnetic pulse within the Earth's magnetosphere caused by an unusually strong, fast shock in the solar wind. Sudden shock-induced injections of electrons with energies above 10 MeV to equatorial distances within 2.5 R E are extremely rare because of the intensity of the shock required. In the current study, the propagation velocity parameter and electric field amplitude of pulses within the magnetosphere in the Li et al. model were varied from 750 to 2500 km/s and 70 to 400 mV/m, respectively. It was found that a stronger electric field shifted the peak of the resultant relativistic electron population toward the Earth. Doubling the electric field amplitude from 120 to 240 mV/m moved the peak of the injected electrons with energies above 13 MeV from 2.8 to 2.4 R E . However, as the electric field pulse becomes even larger, the increase in response diminishes. This asympotic behavior shows that it is extremely difficult to produce energetic electron injections inside two Earth radii. The nominal propagation velocity (velocity parameter) is compared to the radial propagation velocities that would have been measured under this model and others and compared to observation. It is found that although the model radial velocity is smaller than the velocity parameter and decreasing with radial distance, it is faster than MHD results and observations. Decreasing the nominal propagation velocity of the pulse within the magnetosphere from 2500 km/s to 1400 km/s also moved the peak of the injected electrons with energies above 13 MeV slightly closer to the Earth. However, at velocities smaller than approximately 1200 km/s the number of electrons injected within 2.5 Earth radii with energies above 13 MeV greatly decreased. Halving the velocity from 2000 to 1000 km/s shifted the peak of electrons with energy greater than 13 MeV from L = 2.6 to L = 2.4 but produced a count rate reduced by a factor of more than 250, resulting in no significant new radiation belt. These results show that the typical large electromagnetic impulses caused by interplanetary shocks, with amplitudes of the order of 10 mV/m, are more than an order of magnitude too small to produce any significant new radiation belts within 2.5 Earth radii with energies of the order of 10 MeV. Contributing to the difficulty in producing such a new belt is the need for an already relativistic electron population with adequate flux beyond geosynchronous orbit. These results thus also help explain the rarity of events such as the 24 March 1991 injection.Citation: Gannon, J. L., X. Li, and M. Temerin (2005), Parametric study of shock-induced transport and energization of relativistic electrons in the magnetosphere,

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Section: Introductionmentioning

confidence: 99%

Parametric study of shock‐induced transport and energization of relativistic electrons in the magnetosphere

Gannon¹,

Li²,

Temerin³

2005

J. Geophys. Res.

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“…The particle sources in these events can be residual magnetospheric ions and electrons as well as interplanetary solar particles including heavy ions up to Fe. An often-cited example is the 1991 March shock event that created >15 MeV electrons and >50 MeV protons above the inner belt within seconds of its impact on the magnetosphere (Blake et al 1992;Li et al 1993;Hudson et al 1995). Recent measurements have also shown newly trapped radiation belts within L ∼ 2 that are created from solar energetic particles Lorentzen et al 2002).…”

Section: Figmentioning

confidence: 99%

The Relativistic Proton Spectrometer (RPS) for the Radiation Belt Storm Probes Mission

et al. 2012

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The Relativistic Proton Spectrometer (RPS) on the Radiation Belt Storm Probes spacecraft is a particle spectrometer designed to measure the flux, angular distribution, and energy spectrum of protons from ∼60 MeV to ∼2000 MeV. RPS will investigate decadesold questions about the inner Van Allen belt proton environment: a nearby region of space that is relatively unexplored because of the hazards of spacecraft operation there and the difficulties in obtaining accurate proton measurements in an intense penetrating background. RPS is designed to provide the accuracy needed to answer questions about the sources and losses of the inner belt protons and to obtain the measurements required for the nextgeneration models of trapped protons in the magnetosphere. In addition to detailed information for individual protons, RPS features count rates at a 1-second timescale, internal radiation dosimetry, and information about electrostatic discharge events on the RBSP spacecraft that together will provide new information about space environmental hazards in the Earth's magnetosphere. Keywords Scientific GoalsWithin two Earth radii of the Earth's surface there is an unexplored region of trapped particles that are a challenge to accurately measure, a challenge to engineer for spacecraft design, and a challenge to understand given particle lifetimes that can exceed decades or even centuries. The inner Van Allen belt is a nearby reservoir of charged particles from a multitude of sources. We know the existence of trapped protons with energies beyond 1 GeV, secondary particles such as positrons, electrons, and light ions 4 He, 3 He, and 2 H, electrons that diffuse inward from the outer magnetosphere, and heavy ions that originate as interstellar neutral particles. These particles execute their gyration, bounce, and drift motions in a region with a relatively strong and stable magnetic field that shelters them from transients in the geomagnetic field, yielding the longest trapping lifetimes for particles in the Earth's magnetosphere. The tenuous upper atmosphere is both a source and sink of these populations, whose influence varies over the solar cycle and episodically during times of rapid atmospheric joule heating.The Relativistic Proton Spectrometer (RPS) 223Sorting out the various sources and losses in the Inner belt is challenging but there are particle characteristics that aid the process such as: extremely high proton energies that distinguish these particles as having a galactic cosmic ray origin; heavy ion composition that identifies these as being anomalous cosmic rays whose access to the inner belt is only afforded by their being mostly singly-ionized; and antimatter composition that identifies another branch the products of nuclear collisions between galactic cosmic rays and atmospheric atoms. For electrons the picture is less clear since there is little information about the electron energy spectrum and no identifiable characteristics of an electron that originates from a nuclear interaction versus one that diffu...

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“…In the outer region (L [ 3), variations in the proton flux have been observed during the interaction of an interplanetary shock with the Earth's magnetosphere. Shock related compression of the magnetosphere could accelerate protons of solar origin up to tens of MeV within tens of seconds (Blake et al 1992;Hudson et al 1995;Lorentzen et al 2002;Looper et al 2005).…”

Section: Earth's Radiation Beltsmentioning

confidence: 99%

Space Weather: Physics, Effects and Predictability

2010

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The time varying conditions in the near-Earth space environment that may affect space-borne or ground-based technological systems and may endanger human health or life are referred to as space weather. Space weather effects arise from the dynamic and highly variable conditions in the geospace environment starting from explosive events on the Sun (solar flares), Coronal Mass Ejections near the Sun in the interplanetary medium, and various energetic effects in the magnetosphere-ionosphere-atmosphere system. As the utilization of space has become part of our everyday lives, and as our lives have become increasingly dependent on technological systems vulnerable to the space weather influences, the understanding and prediction of hazards posed by these active solar events have grown in importance. In this paper, we review the processes of the Sun-Earth interactions, the dynamic conditions within the magnetosphere, and the predictability of space weather effects on radio waves, satellites and ground-based technological systems today.

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Simulation of proton radiation belt formation during the March 24, 1991 SSC

Cited by 102 publications

References 11 publications

Parametric study of shock‐induced transport and energization of relativistic electrons in the magnetosphere

Parametric study of shock‐induced transport and energization of relativistic electrons in the magnetosphere

The Relativistic Proton Spectrometer (RPS) for the Radiation Belt Storm Probes Mission

Space Weather: Physics, Effects and Predictability

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