The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform

C T Russell - One of the best experts on this subject based on the ideXlab platform.

  • Evidence of coherent drift-resonant acceleration of radiation belt particles by ULF waves
    2013
    Co-Authors: J A Sauvaud, M Walt, C Benoist, E Penou, Y Chen, Dominique Delcourt, C T Russell
    Abstract:

    Evidence is presented for frequent, coherent and powerful accelerations of radiation belt electrons and protons during magnetic storms. Geomagnetic storms are indeed frequently associated with the formation of well developed, multiple bands of energetic electrons inside the inner radiation belt at L=1.1-1.9 and with prominent similar energy structures of protons inside the slot region at L=2.2-3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi- monochromatic Ultra Low Frequency waves (ULF). These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L=1.1. We show that, at the low altitudes of the Demeter spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 second range for L = 1.1-1.9 and in the 60 second range for L=2.2-3.5. Numerical simulations of the coherent drift resonance of energetic particles with Ultra Low Frequency waves show how the particles are accelerated and how the observed structures build up. The structures are formed for interaction times of the order of 20-40 minutes. For longer resonance times, particles are accelerated at energies higher than 1.5 MeV while lower energy particles are decelerated.

  • inner radiation belt particle acceleration and energy structuring by drift resonance with ulf waves during geomagnetic storms
    Journal of Geophysical Research, 2013
    Co-Authors: J A Sauvaud, M Walt, D C Delcourt, C Benoist, E Penou, Y Chen, C T Russell
    Abstract:

    [1] Geomagnetic storms are frequently associated with the formation of multiple bands of energetic electrons inside the inner radiation belt at L = 1.1–1.9 and with prominent energy structures of protons inside the slot region at L = 2.2–3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi-monochromatic ultra-low frequency (ULF) waves. These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L = 1.1. Using low-altitude data from the polar orbiting Demeter spacecraft, we perform case and statistical studies of these structures. We show that with such a spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 s range for L = 1.1–1.9 and in the 60 s range for L = 2.2–3.5. Numerical simulations of the coherent drift resonance of energetic particles with ultra-low frequency waves show how the particles are accelerated and how the observed structures build up.

  • Ion injections and magnetic field oscillations near the high‐latitude magnetopause associated with solar wind dynamic pressure enhancement
    Journal of Geophysical Research, 2004
    Co-Authors: Terrance Onsager, C T Russell
    Abstract:

    [1] The characteristics of particles and magnetic fields associated with a step-like enhancement in solar wind dynamic pressure are investigated by using observations from the Polar spacecraft. At the time, Polar was located near its apogee of ∼9 RE at high latitude in the afternoon sector. Impulsive, energy-dispersed injections of ions were observed by Polar in both parallel and antiparallel pitch angle directions, with a much shorter duration in the parallel direction (toward the Earth) than in the antiparallel direction (away from the Earth). The energies of the injected ions ranged from ∼200 eV to a few keV, and they are considered of magnetosheath origin. The energy dispersion of the injected ions is consistent with the interpretation of the velocity filter or time-of-flight effect as the magnetosheath ions enter the magnetosphere and propagate downward and then are Mirrored at low altitude where magnetic field lines converge. It is estimated that the entrance of the magnetosheath ions was located ∼3.9–7.5 RE away from Polar, and the distance from the spacecraft to the Mirror Point was ∼7.7–8.1 RE, corresponding to ∼830–3600 km in altitude. The Polar data clearly favor magnetic reconnection as the primary mechanism for the transport of magnetosheath plasmas into the magnetosphere. A good correspondence is found between the magnetic field oscillation and the intermittence of the ion injections, implying that the impulsive ion injections were a consequence of the intermittent magnetic reconnection at the high-latitude magnetopause that had been modulated by compressional waves produced by the solar wind dynamic pressure enhancement.

C Benoist - One of the best experts on this subject based on the ideXlab platform.

  • Evidence of coherent drift-resonant acceleration of radiation belt particles by ULF waves
    2013
    Co-Authors: J A Sauvaud, M Walt, C Benoist, E Penou, Y Chen, Dominique Delcourt, C T Russell
    Abstract:

    Evidence is presented for frequent, coherent and powerful accelerations of radiation belt electrons and protons during magnetic storms. Geomagnetic storms are indeed frequently associated with the formation of well developed, multiple bands of energetic electrons inside the inner radiation belt at L=1.1-1.9 and with prominent similar energy structures of protons inside the slot region at L=2.2-3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi- monochromatic Ultra Low Frequency waves (ULF). These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L=1.1. We show that, at the low altitudes of the Demeter spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 second range for L = 1.1-1.9 and in the 60 second range for L=2.2-3.5. Numerical simulations of the coherent drift resonance of energetic particles with Ultra Low Frequency waves show how the particles are accelerated and how the observed structures build up. The structures are formed for interaction times of the order of 20-40 minutes. For longer resonance times, particles are accelerated at energies higher than 1.5 MeV while lower energy particles are decelerated.

  • inner radiation belt particle acceleration and energy structuring by drift resonance with ulf waves during geomagnetic storms
    Journal of Geophysical Research, 2013
    Co-Authors: J A Sauvaud, M Walt, D C Delcourt, C Benoist, E Penou, Y Chen, C T Russell
    Abstract:

    [1] Geomagnetic storms are frequently associated with the formation of multiple bands of energetic electrons inside the inner radiation belt at L = 1.1–1.9 and with prominent energy structures of protons inside the slot region at L = 2.2–3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi-monochromatic ultra-low frequency (ULF) waves. These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L = 1.1. Using low-altitude data from the polar orbiting Demeter spacecraft, we perform case and statistical studies of these structures. We show that with such a spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 s range for L = 1.1–1.9 and in the 60 s range for L = 2.2–3.5. Numerical simulations of the coherent drift resonance of energetic particles with ultra-low frequency waves show how the particles are accelerated and how the observed structures build up.

J A Sauvaud - One of the best experts on this subject based on the ideXlab platform.

  • Evidence of coherent drift-resonant acceleration of radiation belt particles by ULF waves
    2013
    Co-Authors: J A Sauvaud, M Walt, C Benoist, E Penou, Y Chen, Dominique Delcourt, C T Russell
    Abstract:

    Evidence is presented for frequent, coherent and powerful accelerations of radiation belt electrons and protons during magnetic storms. Geomagnetic storms are indeed frequently associated with the formation of well developed, multiple bands of energetic electrons inside the inner radiation belt at L=1.1-1.9 and with prominent similar energy structures of protons inside the slot region at L=2.2-3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi- monochromatic Ultra Low Frequency waves (ULF). These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L=1.1. We show that, at the low altitudes of the Demeter spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 second range for L = 1.1-1.9 and in the 60 second range for L=2.2-3.5. Numerical simulations of the coherent drift resonance of energetic particles with Ultra Low Frequency waves show how the particles are accelerated and how the observed structures build up. The structures are formed for interaction times of the order of 20-40 minutes. For longer resonance times, particles are accelerated at energies higher than 1.5 MeV while lower energy particles are decelerated.

  • inner radiation belt particle acceleration and energy structuring by drift resonance with ulf waves during geomagnetic storms
    Journal of Geophysical Research, 2013
    Co-Authors: J A Sauvaud, M Walt, D C Delcourt, C Benoist, E Penou, Y Chen, C T Russell
    Abstract:

    [1] Geomagnetic storms are frequently associated with the formation of multiple bands of energetic electrons inside the inner radiation belt at L = 1.1–1.9 and with prominent energy structures of protons inside the slot region at L = 2.2–3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi-monochromatic ultra-low frequency (ULF) waves. These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L = 1.1. Using low-altitude data from the polar orbiting Demeter spacecraft, we perform case and statistical studies of these structures. We show that with such a spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 s range for L = 1.1–1.9 and in the 60 s range for L = 2.2–3.5. Numerical simulations of the coherent drift resonance of energetic particles with ultra-low frequency waves show how the particles are accelerated and how the observed structures build up.

Y Chen - One of the best experts on this subject based on the ideXlab platform.

  • Evidence of coherent drift-resonant acceleration of radiation belt particles by ULF waves
    2013
    Co-Authors: J A Sauvaud, M Walt, C Benoist, E Penou, Y Chen, Dominique Delcourt, C T Russell
    Abstract:

    Evidence is presented for frequent, coherent and powerful accelerations of radiation belt electrons and protons during magnetic storms. Geomagnetic storms are indeed frequently associated with the formation of well developed, multiple bands of energetic electrons inside the inner radiation belt at L=1.1-1.9 and with prominent similar energy structures of protons inside the slot region at L=2.2-3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi- monochromatic Ultra Low Frequency waves (ULF). These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L=1.1. We show that, at the low altitudes of the Demeter spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 second range for L = 1.1-1.9 and in the 60 second range for L=2.2-3.5. Numerical simulations of the coherent drift resonance of energetic particles with Ultra Low Frequency waves show how the particles are accelerated and how the observed structures build up. The structures are formed for interaction times of the order of 20-40 minutes. For longer resonance times, particles are accelerated at energies higher than 1.5 MeV while lower energy particles are decelerated.

  • inner radiation belt particle acceleration and energy structuring by drift resonance with ulf waves during geomagnetic storms
    Journal of Geophysical Research, 2013
    Co-Authors: J A Sauvaud, M Walt, D C Delcourt, C Benoist, E Penou, Y Chen, C T Russell
    Abstract:

    [1] Geomagnetic storms are frequently associated with the formation of multiple bands of energetic electrons inside the inner radiation belt at L = 1.1–1.9 and with prominent energy structures of protons inside the slot region at L = 2.2–3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi-monochromatic ultra-low frequency (ULF) waves. These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L = 1.1. Using low-altitude data from the polar orbiting Demeter spacecraft, we perform case and statistical studies of these structures. We show that with such a spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 s range for L = 1.1–1.9 and in the 60 s range for L = 2.2–3.5. Numerical simulations of the coherent drift resonance of energetic particles with ultra-low frequency waves show how the particles are accelerated and how the observed structures build up.

M Walt - One of the best experts on this subject based on the ideXlab platform.

  • Evidence of coherent drift-resonant acceleration of radiation belt particles by ULF waves
    2013
    Co-Authors: J A Sauvaud, M Walt, C Benoist, E Penou, Y Chen, Dominique Delcourt, C T Russell
    Abstract:

    Evidence is presented for frequent, coherent and powerful accelerations of radiation belt electrons and protons during magnetic storms. Geomagnetic storms are indeed frequently associated with the formation of well developed, multiple bands of energetic electrons inside the inner radiation belt at L=1.1-1.9 and with prominent similar energy structures of protons inside the slot region at L=2.2-3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi- monochromatic Ultra Low Frequency waves (ULF). These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L=1.1. We show that, at the low altitudes of the Demeter spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 second range for L = 1.1-1.9 and in the 60 second range for L=2.2-3.5. Numerical simulations of the coherent drift resonance of energetic particles with Ultra Low Frequency waves show how the particles are accelerated and how the observed structures build up. The structures are formed for interaction times of the order of 20-40 minutes. For longer resonance times, particles are accelerated at energies higher than 1.5 MeV while lower energy particles are decelerated.

  • inner radiation belt particle acceleration and energy structuring by drift resonance with ulf waves during geomagnetic storms
    Journal of Geophysical Research, 2013
    Co-Authors: J A Sauvaud, M Walt, D C Delcourt, C Benoist, E Penou, Y Chen, C T Russell
    Abstract:

    [1] Geomagnetic storms are frequently associated with the formation of multiple bands of energetic electrons inside the inner radiation belt at L = 1.1–1.9 and with prominent energy structures of protons inside the slot region at L = 2.2–3.5. These structures typically from 100 keV up to the MeV range result from coherent interactions of energetic particles with quasi-monochromatic ultra-low frequency (ULF) waves. These waves are induced by magnetospheric changes due to the arrival of dense solar material and related nightside injections of particles from the outer magnetosphere that destabilize field lines in the inner magnetosphere down to L = 1.1. Using low-altitude data from the polar orbiting Demeter spacecraft, we perform case and statistical studies of these structures. We show that with such a spacecraft, these structures are best seen near the South Atlantic Anomaly because of lowering of the belt particle Mirror Point. As evidenced from ground measurements, energy bands are associated with quasi-sinusoidal ULF Pc5 and Pc4 waves with periods in the 1000 s range for L = 1.1–1.9 and in the 60 s range for L = 2.2–3.5. Numerical simulations of the coherent drift resonance of energetic particles with ultra-low frequency waves show how the particles are accelerated and how the observed structures build up.