Bibliography



Found 938 entries in the Bibliography.


Showing entries from 901 through 938


2003

Evaluation of quasi-linear diffusion coefficients for EMIC waves in a multispecies plasma

Quasi-linear velocity-space diffusion coefficients due to L-mode electromagnetic ion cyclotron (EMIC) waves are considered in a multispecies plasma. It is shown, with slight approximations to exact cold plasma theory, that within EMIC pass bands the index of refraction is a monotonically increasing function of frequency. Analytical criteria are then derived which identify ranges of latitude, wavenormal angle, and resonance number consistent with resonance in a prescribed wave population. This leads to computational technique ...

Albert, J.;

YEAR: 2003     DOI: 10.1029/2002JA009792

Local Loss due to VLF/ELF/EMIC Waves

Evidence for chorus-driven electron acceleration to relativistic energies from a survey of geomagnetically disturbed periods

We perform a survey of the plasma wave and particle data from the CRRES satellite during 26 geomagnetically disturbed periods to investigate the viability of a local stochastic electron acceleration mechanism to relativistic energies driven by Doppler-shifted cyclotron resonant interactions with whistler mode chorus. Relativistic electron flux enhancements associated with moderate or strong storms may be seen over the whole outer zone (3 < L < 7), typically peaking in the range 4 < L < 5, whereas those associated with weak s ...

Meredith, Nigel; Cain, Michelle; Horne, Richard; Thorne, Richard; Summers, D.; Anderson, Roger;

YEAR: 2003     DOI: 10.1029/2002JA009764

Local Acceleration due to Wave-Particle Interaction

Statistical analysis of relativistic electron energies for cyclotron resonance with EMIC waves observed on CRRES

Electromagnetic ion cyclotron (EMIC) waves which propagate at frequencies below the proton gyrofrequency can undergo cyclotron resonant interactions with relativistic electrons in the outer radiation belt and cause pitch-angle scattering and electron loss to the atmosphere. Typical storm-time wave amplitudes of 1\textendash10 nT cause strong diffusion scattering which may lead to significant relativistic electron loss at energies above the minimum energy for resonance, Emin. A statistical analysis of over 800 EMIC wave event ...

Meredith, Nigel;

YEAR: 2003     DOI: 10.1029/2002JA009700

Local Loss due to VLF/ELF/EMIC Waves

Relativistic electron acceleration and precipitation during resonant interactions with whistler-mode chorus

1] Resonant interactions with whistler-mode chorus waves provide an important process for electron loss and acceleration during storm times. We demonstrate that wave propagation significantly affects the electron scattering rates. We show that stormtime chorus waves outside the plasmapause can scatter equatorial electrons <=60 keV into the loss cone and accelerate trapped electrons up to \~ MeV energies at large pitch-angles. Using ray tracing to map the waves to higher latitudes, we show that the decrease in the ratio betwe ...

Horne, R.;

YEAR: 2003     DOI: 10.1029/2003GL016973

Local Loss due to VLF/ELF/EMIC Waves

Relativistic electron pitch-angle scattering by electromagnetic ion cyclotron waves during geomagnetic storms

[1] During magnetic storms, relativistic electrons execute nearly circular orbits about the Earth and traverse a spatially confined zone within the duskside plasmapause where electromagnetic ion cyclotron (EMIC) waves are preferentially excited. We examine the mechanism of electron pitch-angle diffusion by gyroresonant interaction with EMIC waves as a cause of relativistic electron precipitation loss from the outer radiation belt. Detailed calculations are carried out of electron cyclotron resonant pitch-angle diffusion coef ...

Summers, D.;

YEAR: 2003     DOI: 10.1029/2002JA009489

Local Loss due to VLF/ELF/EMIC Waves

Rebuilding process of the outer radiation belt during the 3 November 1993 magnetic storm: NOAA and Exos-D observations

Using the data from the NOAA and Exos-D satellites during the 3 November 1993 magnetic storm, the dynamic behavior of electrons with energies from a few tens of kiloelectronvolts to a few and its relation to plasma waves were examined. After the late main phase, relativistic electron flux started to recover from the heart of the outer radiation belt, where the cold plasma density was extremely low, and intense whistler mode chorus emissions were detected. The phase space density showed a peak in the outer belt, and the peak ...

Miyoshi, Yoshizumi;

YEAR: 2003     DOI: 10.1029/2001JA007542

Radial Transport

Resonant acceleration and diffusion of outer zone electrons in an asymmetric geomagnetic field

[1] The outer zone radiation belt consists of energetic electrons drifting in closed orbits encircling the Earth between \~3 and 7 RE. Electron fluxes in the outer belt show a strong correlation with solar and magnetospheric activity, generally increasing during geomagnetic storms with associated high solar wind speeds, and increasing in the presence of magnetospheric ULF waves in the Pc-5 frequency range. In this paper, we examine the influence of Pc-5 ULF waves on energetic electrons drifting in an asymmetric, compressed d ...

Elkington, Scot;

YEAR: 2003     DOI: 10.1029/2001JA009202

Radial Transport

2002

X-ray observations of MeV electron precipitation with a balloon-borne germanium spectrometer

The high-resolution germanium detector aboard the MAXIS (MeV Auroral X-ray Imaging and Spectroscopy) balloon payload detected nine X-ray bursts with significant flux extending above 0.5 MeV during an 18 day flight over Antarctica. These minutes-to-hours-long events are characterized by an extremely flat spectrum (\~E-2) similar to the first MeV event discovered in 1996, indicating that the bulk of parent precipitating electrons is at relativistic energies. The MeV bursts were detected between magnetic latitudes 58\textdegree ...

Millan, R.;

YEAR: 2002     DOI: 10.1029/2002GL015922

Local Loss due to VLF/ELF/EMIC Waves

MHD/particle simulations of radiation belt dynamics

Particle fluxes in the outer radiation belts can show substantial variation in time, over scales ranging from a few minutes, such as during the sudden commencement phase of geomagnetic storms, to the years-long variations associated with the progression of the solar cycle. As the energetic particles comprising these belts can pose a hazard to human activity in space, considerable effort has gone into understanding both the source of these particles and the physics governing their dynamical behavior. Computationally tracking ...

ELKINGTON, S; Hudson, M.; Wiltberger, M.J; Lyon, J.;

YEAR: 2002     DOI: 10.1016/S1364-6826(02)00018-4

Shock-Induced Transport. Slot Refilling and Formation of New Belts.

2001

Substorm injection of relativistic electrons to geosynchronous orbit during the great magnetic storm of March 24, 1991

The great March 1991 magnetic storm and the immediately preceding solar energetic particle event (SEP) were among the largest observed during the past solar cycle, and have been the object of intense study. We investigate here, using data from eight satellites, the very large delayed buildup of relativistic electron flux in the outer zone during a 1.5-day period beginning 2 days after onset of the main phase of this storm. A notable feature of the March storm is the intense substorm activity throughout the period of the rela ...

Ingraham, J.; Cayton, T.; Belian, R.; Christensen, R.; Friedel, R.; Meier, M.; Reeves, G.; Takahashi, K;

YEAR: 2001     DOI: 10.1029/2000JA000458

Substorm Injections

2000

Simulation of the outer radiation belt electron flux decrease during the March 26, 1995, magnetic storm

In this paper we study the variation of the relativistic electron fluxes in the Earth\textquoterights outer radiation belt during the March 26, 1995, magnetic storm. Using observations by the radiation environment monitor (REM) on board the space technology research vehicle (STRV-Ib), we discuss the flux decrease and possible loss of relativistic electrons during the storm main phase. In order to explain the observations we have performed fully adiabatic and guiding center simulations for relativistic equatorial electrons in ...

Desorgher, L.; ühler, P.; Zehnder, A.; ückiger, E.;

YEAR: 2000     DOI: 10.1029/2000JA900060

Magnetopause Losses

The temporal evolution of electron distributions and associated wave activity following substorm injections in the inner magnetosphere

The temporal evolution of electron distributions and associated wave activity following substorm injections in the inner magnetosphere are investigated using data from the CRRES satellite. Equatorial electron distributions and concomitant wave spectra outside the plasmapause on the nightside of the Earth are studied as a function of time since injection determined from the auroral-electrojet index (AE). The electron cyclotron harmonic (ECH) wave amplitudes are shown to be very sensitive to small modeling errors in the locati ...

Meredith, Nigel; Horne, Richard; Johnstone, Alan; Anderson, Roger;

YEAR: 2000     DOI: 10.1029/2000JA900010

Substorm Injections

Radial diffusion analysis of outer radiation belt electrons during the October 9, 1990, magnetic storm

The response of outer radiation belt relativistic electrons to the October 9, 1990, magnetic storm is analyzed in detail using a radial diffusion model and data from the Combined Release and Radiation Effects Satellite (CRRES) and the Los Alamos National Laboratory (LANL) geosynchronous satellite 1989-046. Electron measurements are expressed in terms of phase space density as a function of the three adiabatic invariants determined from CRRES magnetic field data and the Tsyganenko 1989 Kp-dependent magnetic field model. The r ...

Brautigam, D.; Albert, J.;

YEAR: 2000     DOI: 10.1029/1999JA900344

Radial Transport

1999

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

There has been increasing evidence that Pc-5 ULF oscillations play a fundamental role in the dynamics of outer zone electrons. In this work we examine the adiabatic response of electrons to toroidal-mode Pc-5 field line resonances using a simplified magnetic field model. We find that electrons can be adiabatically accelerated through a drift-resonant interaction with the waves, and present expressions describing the resonance condition and half-width for resonant interaction. The presence of magnetospheric convection electri ...

Elkington, Scot; Hudson, M.; Chan, Anthony;

YEAR: 1999     DOI: 10.1029/1999GL003659

Radial Transport

Simulation of Radiation Belt Dynamics Driven by Solar Wind Variations

The rapid rise of relativistic electron fluxes inside geosynchronous orbit during the January 10-11, 1997, CME-driven magnetic cloud event has been simulated using a relativistic guiding center test particle code driven by out-put from a 3D global MHD simulation of the event. A comparison can be made of this event class, characterized by a moderate solar wind speed (< 600 km/s), and those commonly observed at the last solar maximum with a higher solar wind speed and shock accelerated solar energetic proton component. Relati ...

Hudson, M.; Elkington, S.; Lyon, J.; Goodrich, C.; Rosenberg, T.;

YEAR: 1999     DOI: 10.1029/GM10910.1029/GM109p0171

1998

Relativistic theory of wave-particle resonant diffusion with application to electron acceleration in the magnetosphere

Resonant diffusion curves for electron cyclotron resonance with field-aligned electromagnetic R mode and L mode electromagnetic ion cyclotron (EMIC) waves are constructed using a fully relativistic treatment. Analytical solutions are derived for the case of a single-ion plasma, and a numerical scheme is developed for the more realistic case of a multi-ion plasma. Diffusion curves are presented, for plasma parameters representative of the Earth\textquoterights magnetosphere at locations both inside and outside the plasmapause ...

Summers, D.; Thorne, Richard; Xiao, Fuliang;

YEAR: 1998     DOI: 10.1029/98JA01740

Local Acceleration due to Wave-Particle Interaction

Substorm electron injections: Geosynchronous observations and test particle simulations

We investigate electron acceleration and the flux increases associated with energetic electron injections on the basis of geosynchronous observations and test-electron orbits in the dynamic fields of a three-dimensional MHD simulation of neutral line formation and dipolarization in the magnetotail. This complements an earlier investigation of test protons [Birn et al., 1997b]. In the present paper we consider equatorial orbits only, using the gyrocenter drift approximation. It turns out that this approximation is valid for e ...

Birn, J.; Thomsen, M.; Borovsky, J.; Reeves, G.; McComas, D.; Belian, R.; Hesse, M.;

YEAR: 1998     DOI: 10.1029/97JA02635

Substorm Injections

Electron scattering loss in Earth\textquoterights inner magnetosphere 1. Dominant physical processes

Pitch angle diffusion rates due to Coulomb collisions and resonant interactions with plasmaspheric hiss, lightning-induced whistlers and anthropogenic VLF transmissions are computed for inner magnetospheric electrons. The bounce-averaged, quasi-linear pitch angle diffusion coefficients are input into a pure pitch angle diffusion equation to obtain L and energy dependent equilibrium distribution functions and precipitation lifetimes. The relative effects of each scattering mechanism are considered as a function of electron en ...

Abel, Bob; Thorne, Richard;

YEAR: 1998     DOI: 10.1029/97JA02919

Local Loss due to VLF/ELF/EMIC Waves

1997

Multisatellite observations of the outer zone electron variation during the November 3\textendash4, 1993, magnetic storm

The disappearance and reappearance of outer zone energetic electrons during the November 3\textendash4, 1993, magnetic storm is examined utilizing data from the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX), the Global Positioning System (GPS) series, and the Los Alamos National Laboratory (LANL) sensors onboard geosynchronous satellites. The relativistic electron flux drops during the main phase of the magnetic storm in association with the large negative interplanetary Bz and rapid solar wind pressure inc ...

Li, Xinlin; Baker, D.; Temerin, M.; Cayton, T.; Reeves, E.; Christensen, R.; Blake, J.; Looper, M.; Nakamura, R.; Kanekal, S.;

YEAR: 1997     DOI: 10.1029/97JA01101

Magnetopause Losses

1994

Large amplitude electric and magnetic field signatures in the inner magnetosphere during injection of 15 MeV electron drift echoes

Electric and magnetic fields were measured by the CRRES spacecraft at an L-value of 2.2 to 2.6 near 0300 magnetic local time during a strong storm sudden commencement (SSC) on March 24, 1991. The electric field signature at the spacecraft at the time of the SSC was characterized by a large amplitude oscillation (80 mV/m peak to peak) with a period corresponding to the 150 second drift echo period of the simultaneously observed 15 MeV electrons. Considerations of previous statistical studies of the magnitude of SSC electric a ...

Wygant, J.; Mozer, F.; Temerin, M.; Blake, J.; Maynard, N.; Singer, H.; Smiddy, M.;

YEAR: 1994     DOI: 10.1029/94GL00375

Shock-Induced Transport. Slot Refilling and Formation of New Belts.

1993

Simulation of the prompt energization and transport of radiation belt particles during the March 24, 1991 SSC

We model the rapid (\~ 1 min) formation of a new electron radiation belt at L ≃ 2.5 that resulted from the Storm Sudden Commencement (SSC) of March 24, 1991 as observed by the CRRES satellite. Guided by the observed electric and magnetic fields, we represent the time-dependent magnetospheric electric field during the SSC by an asymmetric bipolar pulse that is associated with the compression and relaxation of the Earth\textquoterights magnetic field. We follow the electrons using a relativistic guiding center code. The test ...

Li, Xinlin; Roth, I.; Temerin, M.; Wygant, J.; Hudson, M.; Blake, J.;

YEAR: 1993     DOI: 10.1029/93GL02701

Shock-Induced Transport. Slot Refilling and Formation of New Belts.

1988

Simultaneous Radial and Pitch Angle Diffusion in the Outer Electron Radiation Belt

A solution of the bimodal (radial and pitch angle) diffusion equation for the radiation belts is developed with special regard for the requirements of satellite radiation belt data analysis. In this paper, we use this solution to test the bimodal theory of outer electron belt diffusion by confronting it with satellite data. Satellite observations, usually over finite volumes of (L, t) space, are seldom sufficient in space-time duration to cover the relaxation to equilibrium of the entire radiation belt. Since time scales of ...

Chiu, Y.; Nightingale, R.; Rinaldi, M.;

YEAR: 1988     DOI: 10.1029/JA093iA04p02619

Radial Transport

1981

The Dynamics of Energetic Electrons in the Earth\textquoterights Outer Radiation Belt During 1968 as Observed by the Lawrence Livermore National Laboratory\textquoterights Spectrometer on Ogo 5

An account is given of measurements of electrons made by the LLNL magnetic electron spectrometer (60\textendash3000 keV in seven differential energy channels) on the Ogo 5 satellite in the earth\textquoterights outer-belt regions during 1968 and early 1969. The data were analyzed to identify those features dominated by pitch angle and radial diffusion; in doing so all aspects of phase space covered by the data were studied, including pitch angle distributions and spectral features, as well as decay rates. The pitch angle dis ...

West, H.; Buck, R.; Davidson, G.;

YEAR: 1981     DOI: 10.1029/JA086iA04p02111

Radial Transport

1979

Direct Evaluation of the Radial Diffusion Coefficient near L = 6 Due to Electric Field Fluctuations

The radial diffusion coefficient for radiation belt particles near L=6 has been calculated from the measured electric field fluctuations. Simultaneous balloon flights in August 1974 from six auroral zone sites ranging 180\textdegree in magnetic longitude produced the electric field data. The large scale slowly varying ionospheric electric fields from these flights have been mapped to the equator during the quiet magnetic conditions of this campaign. These mapped equatorial electric fields were then Fourier transformed in spa ...

Holzworth, R.; Mozer, F.;

YEAR: 1979     DOI: 10.1029/JA084iA06p02559

Radial Transport

1973

ULF Geomagnetic Power near L = 4, 2. Temporal Variation of the Radial Diffusion Coefficient for Relativistic Electrons

Measurements at conjugate points on the ground near L = 4 of the power spectra of magnetic-field fluctuations in the frequency range 0.5 to 20 mHz are used as a means of estimating daily values for the relativistic-electron radial-diffusion coefficient DLL for two periods in December 1971 and January 1972. The values deduced for L-10 DLL show a strong variation with magnetic activity, as measured by the Fredricksburg magnetic index KFR. The radial-diffusion coefficient typically increases by a factor of \~10 for a unit incre ...

Lanzerotti, L.; Morgan, Caroline;

YEAR: 1973     DOI: 10.1029/JA078i022p04600

Radial Transport

Equilibrium Structure of Radiation Belt Electrons

The detailed quiet time structure of energetic electrons in the earth\textquoterights radiation belts is explained on the basis of a balance between pitch angle scattering loss and inward radial diffusion from an average outer zone source. Losses are attributed to a combination of classical Coulomb scattering at low L and whistler mode turbulent pitch angle diffusion throughout the outer plasmasphere. Radial diffusion is driven by substorm associated fluctuations of the magnetospheric convection electric field.

Lyons, Lawrence; Thorne, Richard;

YEAR: 1973     DOI: 10.1029/JA078i013p02142

Local Loss due to VLF/ELF/EMIC Waves

1972

Parasitic Pitch Angle Diffusion of Radiation Belt Particles by Ion Cyclotron Waves

The resonant pitch angle scattering of protons and electrons by ion cyclotron turbulence is investigated. The analysis is analogous to that recently performed for electron interactions with whistler mode waves. The role played by the intense band of ion cyclotron waves, predicted to be generated just within the plasmapause during the decay of the magnetospheric ring current, is evaluated in detail. Loss rates resulting from parasitic interactions with this turbulence are determined for energetic protons and relativistic elec ...

Lyons, Lawrence; Thorne, Richard;

YEAR: 1972     DOI: 10.1029/JA077i028p05608

Local Loss due to VLF/ELF/EMIC Waves

Inner-Zone Energetic-Electron Repopulation by Radial Diffusion

A quantitative study of the intrusion of natural electrons into the inner radiation zone during and after the geomagnetic storm of September 2, 1966, shows that the transport is consistent with a radial-diffusion mechanism in which the first two invariants are conserved. Except for the 3-day period of the storm main phase when data were missing, the radial-diffusion coefficient is D = 2.7 \texttimes 10-5 L7.9 μ-0.5 day-1 in the range 1.7 <= L <= 2.6 and 13.3 <= μ <= 27.4 Mev gauss-1. This value could be produced by variati ...

Tomassian, Albert; Farley, Thomas; Vampola, Alfred;

YEAR: 1972     DOI: 10.1029/JA077i019p03441

Radial Transport

1970

Radial Diffusion of Outer-Zone Electrons: An Empirical Approach to Third-Invariant Violation

The near-equatorial fluxes of outer-zone electrons (E>0.5 Mev and E>1.9 Mev) measured by an instrument on the satellite Explorer 15 following the geomagnetic storm of December 17\textendash18, 1962, are used to determine the electron radial diffusion coefficients and electron lifetimes as functions of L for selected values of the conserved first invariant \textmu. For each value of \textmu, the diffusion coefficient is assumed to be time-independent and representable in the form D = DnLn. The diffusion coefficients and lifet ...

Lanzerotti, L.; Maclennan, C.; Schulz, Michael;

YEAR: 1970     DOI: 10.1029/JA075i028p05351

Radial Transport

1969

Radial Diffusion of Starfish Electrons

A study of the change in electron intensities in the Starfish electron belt from January 1, 1963, to November 3, 1965, indicates that radial diffusion, both inward and outward from L of 1.40, was a significant loss mechanism for these electrons during this period. For L values of 1.20 and below, the indicated steepening of the pitch-angle distributions during this period has been interpreted as the result of a radial diffusion source for each L shell concentrated near the geomagnetic equator. Since pitch-angle diffusion life ...

Farley, Thomas;

YEAR: 1969     DOI: 10.1029/JA074i014p03591

Radial Transport

Convection Electric Fields and the Diffusion of Trapped Magnetospheric Radiation

We explore here the possible importance of time-dependent convection electric fields as an agent for diffusing trapped magnetospheric radiation inward toward the earth. By using a formalism (Birmingham, Northrop, and Fälthammar, 1967) based on first principles, and by adopting a simple model for the magnetosphere and its electric field, we succeed in deriving a one-dimensional diffusion equation to describe statistically the loss-free motion of mirroring particles with arbitrary but conserved values of the first two adiabat ...

Birmingham, Thomas;

YEAR: 1969     DOI: 10.1029/JA074i009p02169

Radial Transport

Diffusion of Equatorial Particles in the Outer Radiation Zone

Expansions and contractions of the permanently compressed magnetosphere lead to the diffusion of equatorially trapped particles across drift shells. A general technique for obtaining the electric fields induced by these expansions and contractions is described and applied to the Mead geomagnetic field model. The resulting electric drifts are calculated and are superimposed upon the gradient drift executed by a particle that conserves its first (μ) and second (J = 0) adiabatic invariants. The noon-midnight asymmetry of the u ...

Schulz, Michael; Eviatar, Aharon;

YEAR: 1969     DOI: 10.1029/JA074i009p02182

Radial Transport

Particle fluxes in the outer geomagnetic field

The outer geomagnetic field comprises the outer radiation belt, consisting of electrons with energies of 104\textendash107 ev, and the unstable radiation zone. The outer radiation belt is bounded on its inner side by a gap, which is at various times located at a distance of 2.2\textendash3.5 RE and in which a considerable precipitation of electrons from radiation belts occurs, possibly owing to a high intensity of electromagnetic waves. The boundary separating the outer radiation belt from the unstable radiation zone is at ...

Vernov, S.; Gorchakov, E.; Kuznetsov, S.; Logachev, Yu.; Sosnovets, E.; Stolpovsky, V.;

YEAR: 1969     DOI: 10.1029/RG007i001p00257

Radial Transport

1968

Radial Diffusion Coefficient for Electrons at 1.76 < L < 5

Radial diffusion by nonconservation of the third adiabatic invariant of particle motion is assumed in analyzing experiments in which electrons appeared to move across field lines. Time-dependent solutions of the Fokker-Planck diffusion equation are obtained numerically and fitted to the experimental results by adjusting the diffusion coefficient. Values deduced for the diffusion coefficient vary from 1.3 \texttimes 10-5 RE\texttwosuperior/day at L = 1.76 to 0.10 RE\texttwosuperior/day at L = 5. In the interval 2.6 < L < 5, t ...

Newkirk, L.; Walt, M.;

YEAR: 1968     DOI: 10.1029/JA073i023p07231

Radial Transport

Radial Diffusion Coefficient for Electrons at Low L Values

An empirical evaluation of the diffusion coefficient for trapped electrons diffusing across low L shells is obtained by adjusting the coefficient to account for the observed radial profile and the long-term decay rate of the trapped electron flux. The diffusion mechanism is not identified, but it is assumed that the adiabatic invariants \textmu and J are conserved. The average value of the coefficient for electrons > 1.6 Mev energy is found to decrease monotonically from \~4 \texttimes 10-6 RE\texttwosuperior/day at L = 1.16 ...

Newkirk, L.; Walt, M.;

YEAR: 1968     DOI: 10.1029/JA073i003p01013

Radial Transport

1966

Velocity Space Diffusion from Weak Plasma Turbulence in a Magnetic Field

The quasi-linear velocity space diffusion is considered for waves of any oscillation branch propagating at an arbitrary angle to a uniform magnetic field in a spatially uniform plasma. The space-averaged distribution function is assumed to change slowly compared to a gyroperiod and characteristic times of the wave motion. Nonlinear mode coupling is neglected. An H-like theorem shows that both resonant and nonresonant quasi-linear diffusion force the particle distributions towards marginal stablity. Creation of the marginally ...

Kennel, C.;

YEAR: 1966     DOI: 10.1063/1.1761629

Local Loss due to VLF/ELF/EMIC Waves

Limit on Stably Trapped Particle Fluxes

Whistler mode noise leads to electron pitch angle diffusion. Similarly, ion cyclotron noise couples to ions. This diffusion results in particle precipitation into the ionosphere and creates a pitch angle distributon of trapped particles that is unstable to further wave growth. Since excessive wave growth leads to rapid diffusion and particle loss, the requirement that the growth rate be limited to the rate at which wave energy is depleted by wave propagation permits an estimate of an upper limit to the trapped equatorial par ...

Kennel, C.; Petschek, H.;

YEAR: 1966     DOI: 10.1029/JZ071i001p00001

Local Loss due to VLF/ELF/EMIC Waves

1965

Effects of time-dependent electric fields on geomagnetically trapped radiation.

Large-scale electric potential fields in the magnetosphere are generally invoked in theories of the aurora. It is shown in the present article that irregular fluctuations of such fields cause a random radial motion of trapped energetic particles by violating the third adiabatic invariant. When the first and second invariants are conserved, any radial motion of the particles is associated with a corresponding energy change. Some particles move outward and others inward; but, if there is a source in the outer magnetosphere and ...

Falthammar, C.-G;

YEAR: 1965     DOI: 10.1029/JZ070i011p02503

Radial Transport



  14      15      16      17      18      19