Acceleration of relativistic electrons via drift‐resonant interaction with toroidal‐mode Pc‐5 ULF oscillations

Elkington, S. R.; Hudson, M. K.; Chan, A. A.

doi:10.1029/1999gl003659

Cited by 416 publications

(431 citation statements)

References 13 publications

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“…Several possible mechanisms have been proposed (Li and Temerin 2001;Friedel et al 2002;Horne 2002). Betatron and Fermi acceleration as a result of transport across the magnetic field (radial diffusion towards the Earth) becomes much more efficient when ULF waves at frequencies of a few Hz are present (Elkington et al 1999). This is corroborated by the high correlation between the occurrence of ULF waves, flux increases and the speed of solar wind (Mathie and Mann 2000;Horne et al 2005).…”

Section: Earth's Radiation Beltssupporting

confidence: 53%

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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Section: Earth's Radiation Beltssupporting

confidence: 53%

Space Weather: Physics, Effects and Predictability

2010

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“…ULF waves, with periods comparable to tens of minutes, cause a violation of the third invariant, resulting in radial diffusion. Since the power in ULF waves is considerably enhanced during magnetic storms (Mathie and Mann 2000), radial diffusion is a potentially important mechanism for energetic electron acceleration (Rostoker et al 1998;Elkington et al 1999;Hudson et al 2001;O'Brien et al 2001;Shprits and Thorne 2004) or loss (Shprits et al 2006;Jordanova et al 2008;) during storm conditions, dependent on the radial gradient in phase space density. Higher frequency ELF and VLF waves cause violation of the first two invariants and lead to pitch angle scattering loss to the atmosphere (Thorne and Kennel 1971;Lyons et al 1972;Thorne 1998a, 1998b) or local stochastic energy diffusion (Horne and Thorne 1998;Summers et al 1998;Miyoshi et al 2003).…”

Section: Introductionmentioning

confidence: 99%

The Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) on RBSP

et al. 2013

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The Electric and Magnetic Field Instrument and Integrated Science (EMFISIS) investigation on the NASA Radiation Belt Storm Probes (now named the Van Allen Probes) mission provides key wave and very low frequency magnetic field measurements to understand radiation belt acceleration, loss, and transport. The key science objectives and the contribution that EMFISIS makes to providing measurements as well as theory and modeling are described. The key components of the instruments suite, both electronics and sensors, including key functional parameters, calibration, and performance, demonstrate that EMFI-SIS provides the needed measurements for the science of the RBSP mission. The EMFISIS operational modes and data products, along with online availability and data tools provide the radiation belt science community with one the most complete sets of data ever collected.

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“…The time scale of the transport is consistent with the drift resonant acceleration process proposed by Hudson et al (1999; and analyzed in detail by Elkington et al (1999), who followed a smaller number of test particles in a simplified field model. Acceleration via drift resonance with the radial electric field compo nent comes about because of the non-axisymmetric drift path .…”

Section: Discussionmentioning

confidence: 60%

“…To simplify the analysis, Elkington et al (1999) as sumed a tailward displaced dipole magnetic field and a superposed electric field including a uniform dawn-dusk convection field and a summation over m of sinousoidal radial and azimuthal oscilatory components, to simulate poloidal and toroidal modes:…”

Section: Discussionmentioning

confidence: 99%

Radiation Belt Electron Acceleration by ULF Wave Drift Resonance: Simulation of 1997 and 1998 Storms

Hudson

Elkington

Lyon

et al. 2013

Geophysical Monograph Series

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Pc 5 ULF waves are seen concurrently with the rise in radiation belt fluxes associated with CME-magnetic cloud events. Four such geomagnetic storm periods in 1997 and 1998, 10-11 January and 14-15 May, 1997; 1-4 May and 26-28 August, 1998, have been simulated with a 3D global MHD code driven by Ll-measured solar wind parameters. The field output has been used to advance electron guiding center trajectories in the equatorial plane. The time series has also been analyzed for ULF wave mode structure. Toroidal field line resonances with low azimuthal mode number and frequencies com mensurate with the electron drift period are identified in the radial electric field component, along with enhanced power in the poloidal (azimuthal) elec tric field component. The simulated time scale for inward radial transport of electrons in the several hundred keV to MeV energy range, from geosyn chronous orbit to L=3-4, varies with the level of ULF wave power and overall energy input to the magnetosphere. Of the four events studied, the May 1998 storm period was most geoeffective and the January 1997 least so, in terms of simulated radial transport and energization of electrons. This transport rate is consistent with the level of ULF waves excited in the simulations, and the proposed drift resonant acceleration mechanism.

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Acceleration of relativistic electrons via drift‐resonant interaction with toroidal‐mode Pc‐5 ULF oscillations

Cited by 416 publications

References 13 publications

Space Weather: Physics, Effects and Predictability

Space Weather: Physics, Effects and Predictability

The Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) on RBSP

Radiation Belt Electron Acceleration by ULF Wave Drift Resonance: Simulation of 1997 and 1998 Storms

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