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Found 1116 entries in the Bibliography.
Showing entries from 1101 through 1116
| 2001 |
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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 relativistic flux buildup, and the good correlation between some temporal features of the lower-energy substorm-injected electron flux and the relativistic electron flux at geosynchronous orbit. Velocity dispersion analysis of these fluxes between geosynchronous satellites near local midnight and local noon shows evidence that both classes of electrons arrive at geosynchronous nearly simultaneously within a few hours of local midnight. From this we conclude that for this storm period the substorm inductive electric field transports not only the usual (50\textendash300 keV) substorm electrons but also the relativistic (0.3 to several MeV) electrons to geosynchronous orbit. A simplified calculation of the electron ε \texttimes B and gradient/curvature drifts indicates that sufficiently strong substorm dipolarization inductive electric fields (≳ 10 mV/m) could achieve this, provided sufficient relativistic electrons are present in the source region. Consistent with this interpretation, we find that the injected relativistic electrons have a pitch angle distribution that is markedly peaked perpendicular to the magnetic field. Furthermore, the equatorial phase space density at geosynchronous orbit (L = 6.7) is greater than it is at GPS orbit at the equator (L = 4.2) throughout this buildup period, indicating that a source for the relativistic electrons lies outside geosynchronous orbit during this time. Earthward transport of the relativistic electrons by large substorm dipolarization fields, since it is unidirectional, would constitute a strong addition to the transport by radial diffusion and, when it occurs, could result in unusually strong relativistic fluxes, as is reported here for this magnetic storm. Ingraham, J.; Cayton, T.; Belian, R.; Christensen, R.; Friedel, R.; Meier, M.; Reeves, G.; Takahashi, K; Published by: Journal of Geophysical Research Published on: 11/2001 YEAR: 2001 DOI: 10.1029/2000JA000458 |
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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 relativistic flux buildup, and the good correlation between some temporal features of the lower-energy substorm-injected electron flux and the relativistic electron flux at geosynchronous orbit. Velocity dispersion analysis of these fluxes between geosynchronous satellites near local midnight and local noon shows evidence that both classes of electrons arrive at geosynchronous nearly simultaneously within a few hours of local midnight. From this we conclude that for this storm period the substorm inductive electric field transports not only the usual (50\textendash300 keV) substorm electrons but also the relativistic (0.3 to several MeV) electrons to geosynchronous orbit. A simplified calculation of the electron ε \texttimes B and gradient/curvature drifts indicates that sufficiently strong substorm dipolarization inductive electric fields (≳ 10 mV/m) could achieve this, provided sufficient relativistic electrons are present in the source region. Consistent with this interpretation, we find that the injected relativistic electrons have a pitch angle distribution that is markedly peaked perpendicular to the magnetic field. Furthermore, the equatorial phase space density at geosynchronous orbit (L = 6.7) is greater than it is at GPS orbit at the equator (L = 4.2) throughout this buildup period, indicating that a source for the relativistic electrons lies outside geosynchronous orbit during this time. Earthward transport of the relativistic electrons by large substorm dipolarization fields, since it is unidirectional, would constitute a strong addition to the transport by radial diffusion and, when it occurs, could result in unusually strong relativistic fluxes, as is reported here for this magnetic storm. Ingraham, J.; Cayton, T.; Belian, R.; Christensen, R.; Friedel, R.; Meier, M.; Reeves, G.; Takahashi, K; Published by: Journal of Geophysical Research Published on: 11/2001 YEAR: 2001 DOI: 10.1029/2000JA000458 |
| 2000 |
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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 the nonstationary Tsygarienko96 magnetospheric magnetic field model. In our simulations the drift of electrons through the magnetopause was considered as a loss process. We present our model results and discuss their dependence on the magnetospheric magnetic and electric field model, as well as on the prestorm fluxes used in the simulations. Desorgher, L.; ühler, P.; Zehnder, A.; ückiger, E.; Published by: Journal of Geophysical Research Published on: 09/2000 YEAR: 2000 DOI: 10.1029/2000JA900060 |
| 1999 |
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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 electric fields is seen to increase the rate of resonant energization, and allow bulk acceleration of radiation belt electrons. Conditions leading to the greatest rate of acceleration in the proposed mechanism, a nonaxisymmetric magnetic field, superimposed toroidal oscillations, and strong convection electric fields, are likely to prevail during storms associated with high solar wind speeds. Elkington, Scot; Hudson, M.; Chan, Anthony; Published by: Geophysical Research Letters Published on: 11/1999 YEAR: 1999 DOI: 10.1029/1999GL003659 |
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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. Relativistic electron flux increase occurred over several hours for the January event, during a period of prolonged southward IMF Bz more rapidly than the 1-2 day delay typical of flux increases driven by solar wind high speed stream interactions. Simulations of the January event captured the flux Hudson, M.; Elkington, S.; Lyon, J.; Goodrich, C.; Rosenberg, T.; Published by: Published on: YEAR: 1999 DOI: 10.1029/GM10910.1029/GM109p0171 |
| 1998 |
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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 electrons prior to and during the flux rises observed in the near tail region of the model at all energies considered (\~ 100 eV to 1 MeV). The test particle model reproduces major observed characteristics: a fast flux rise, comparable to that of the ions, and the existence of five categories of dispersionless events, typical for observations at different local times. They consist of dispersionless injections of ions or electrons without accompanying injections of the other species, delayed electron injections and delayed ion injections, and simultaneous two-species injections. As postulated from observations [Birn et al., 1997a], these categories can be attributed to a dawn-dusk displacement of the ion and electron injection boundaries in combination with an earthward motion or expansion. The simulated electron injection region extends farther toward dusk at lower energies (say, below 40 keV) than at higher energies. This explains the existence of observed energetic ion injections that are accompanied by electron flux increases at the lower energies but not by an energetic electron injection at energies above 50 keV. The simulated distributions show that flux increases are limited in energy, as observed. The reason for this limitation and for the differences between the injection regions at different energies is the localization in the dawn-dusk direction of the tail collapse and the associated cross-tail electric field, in combination with a difference in the relative importance of E \texttimes B drift and gradient drifts at different energies. The results demonstrate that the collapsing field region earthward of the neutral line appears to be more significant than the neutral line itself for the acceleration of electrons, particularly for the initial rise of the fluxes and the injection boundary. This is similar to the result obtained for test ions [Birn et al., 1997b]. Birn, J.; Thomsen, M.; Borovsky, J.; Reeves, G.; McComas, D.; Belian, R.; Hesse, M.; Published by: Journal of Geophysical Research Published on: 05/1998 YEAR: 1998 DOI: 10.1029/97JA02635 |
| 1997 |
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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 increase late on November 3. Outer zone electrons with E > 3 MeV measured by SAMPEX disappear for over 12 hours at the beginning of November 4. This represents a 3 orders of magnitude decrease down to the cosmic ray background of the detector. GPS and LANL sensors show similar effects, confirming that the flux drop of the energetic electrons occurs near the magnetic equator and at all pitch angles. Enhanced electron precipitation was measured by SAMPEX at L >= 3.5. The outer zone electron fluxes then recover and exceed prestorm levels within one day of the storm onset and the inner boundary of the outer zone moves inward to smaller L (<3). These multiple-satellite measurements provide a data set which is examined in detail and used to determine the mechanisms contributing to the loss and recovery of the outer zone electron flux. The loss of the inner part of the outer zone electrons is partly due to the adiabatic effects associated with the decrease of Dst, while the loss of most of the outer part (those electrons initially at L >= 4.0) are due to either precipitation into the atmosphere or drift to the magnetopause because of the strong compression of the magnetosphere by the solar wind. The recovery of the energetic electron flux is due to the adiabatic effects associated with the increase in Dst, and at lower energies (<0.5 MeV) due to rapid radial diffusion driven by the strong magnetic activity during the recovery phase of the storm. Heating of the electrons by waves may contribute to the energization of the more energetic part (>1.0 MeV) of the outer zone electrons. Li, Xinlin; Baker, D.; Temerin, M.; Cayton, T.; Reeves, E.; Christensen, R.; Blake, J.; Looper, M.; Nakamura, R.; Kanekal, S.; Published by: Journal of Geophysical Research Published on: 01/1997 YEAR: 1997 DOI: 10.1029/97JA01101 |
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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 increase late on November 3. Outer zone electrons with E > 3 MeV measured by SAMPEX disappear for over 12 hours at the beginning of November 4. This represents a 3 orders of magnitude decrease down to the cosmic ray background of the detector. GPS and LANL sensors show similar effects, confirming that the flux drop of the energetic electrons occurs near the magnetic equator and at all pitch angles. Enhanced electron precipitation was measured by SAMPEX at L >= 3.5. The outer zone electron fluxes then recover and exceed prestorm levels within one day of the storm onset and the inner boundary of the outer zone moves inward to smaller L (<3). These multiple-satellite measurements provide a data set which is examined in detail and used to determine the mechanisms contributing to the loss and recovery of the outer zone electron flux. The loss of the inner part of the outer zone electrons is partly due to the adiabatic effects associated with the decrease of Dst, while the loss of most of the outer part (those electrons initially at L >= 4.0) are due to either precipitation into the atmosphere or drift to the magnetopause because of the strong compression of the magnetosphere by the solar wind. The recovery of the energetic electron flux is due to the adiabatic effects associated with the increase in Dst, and at lower energies (<0.5 MeV) due to rapid radial diffusion driven by the strong magnetic activity during the recovery phase of the storm. Heating of the electrons by waves may contribute to the energization of the more energetic part (>1.0 MeV) of the outer zone electrons. Li, Xinlin; Baker, D.; Temerin, M.; Cayton, T.; Reeves, E.; Christensen, R.; Blake, J.; Looper, M.; Nakamura, R.; Kanekal, S.; Published by: Journal of Geophysical Research Published on: 01/1997 YEAR: 1997 DOI: 10.1029/97JA01101 |
| 1988 |
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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 continuous data coverage are often comparable to that of radiation belt disturbances, it is therefore inappropriate to apply impulsive semi-infinite time response solutions of diffusion theory to interpret data from a finite window of (L, t) space. Observational limitations indicate that appropriate solutions for the interpretation of satellite data are general solutions for a finite-volume boundary value problem in bimodal diffusion. Here we test such a solution as the prime candidate for comprehensive radiation belt dynamic modeling by applying the solution and developing a method of analysis to radiation belt electron data obtained by the SCATHA satellite at moderate geomagnetic activity. The results and the generality of our solution indicate its promise as a new approach to dynamic modeling of the radiation belts. Chiu, Y.; Nightingale, R.; Rinaldi, M.; Published by: Journal of Geophysical Research Published on: 04/1988 YEAR: 1988 DOI: 10.1029/JA093iA04p02619 |
| 1981 |
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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 distributions are reported elsewhere. The spectra observed in the weeks after a storm at L \~3\textendash4.5 show the evolution of a peak at \~1.5 MeV and pronounced minima at \~0.5 MeV. The observed pitch angle diffusion lifetimes are identified as being the shortest decays observed and are found to be highly energy and L dependent with minimum lifetimes of \~1\textendash2 days occurring at L \~3\textendash4.5. Two contiguous periods of decay, following the intense storm injection on October 31 and November 1, were analyzed in terms of radial diffusion. Significant differences were found between the derived values of DLL for the two periods; also significant energy dependence shows in the results. Although the values of DLL vary by about a factor of 10, representative values are 0.3 day-1 at L=6, 0.06 at L=4, 0.015 at L=3, and 0.001 at L=2.5. Despite the wide variation of many prior results in the literature, there is a family of results in approximate agreement with the present results. By noting the variations in DLL, as a function of the invariant quantities, we are able to order a fair body of previous results with our new results. West, H.; Buck, R.; Davidson, G.; Published by: Journal of Geophysical Research Published on: 04/1981 YEAR: 1981 DOI: 10.1029/JA086iA04p02111 |
| 1970 |
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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 lifetimes are then simultaneously obtained by requiring that the L-dependent reciprocal electron lifetime, as determined from the Fokker-Planck equation, deviate minimally from a constant in time. Applied to the data, these few assumptions yield a value of D that is smaller by approximately a factor of 10 than the value recently found by Newkirk and Walt in a separate analysis of 1.6-Mev electron data obtained during the same time period on another satellite. The electron lifetimes are found to be strong functions of L, with 4- to 6-day lifetimes observed at the higher L values (4.6\textendash4.8). Lanzerotti, L.; Maclennan, C.; Schulz, Michael; Published by: Journal of Geophysical Research Published on: 10/1970 YEAR: 1970 DOI: 10.1029/JA075i028p05351 |
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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 lifetimes are then simultaneously obtained by requiring that the L-dependent reciprocal electron lifetime, as determined from the Fokker-Planck equation, deviate minimally from a constant in time. Applied to the data, these few assumptions yield a value of D that is smaller by approximately a factor of 10 than the value recently found by Newkirk and Walt in a separate analysis of 1.6-Mev electron data obtained during the same time period on another satellite. The electron lifetimes are found to be strong functions of L, with 4- to 6-day lifetimes observed at the higher L values (4.6\textendash4.8). Lanzerotti, L.; Maclennan, C.; Schulz, Michael; Published by: Journal of Geophysical Research Published on: 10/1970 YEAR: 1970 DOI: 10.1029/JA075i028p05351 |
| 1969 |
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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 unperturbed drift trajectory (resulting from gradient drift alone) is approximated by means of a simple model. In this model the angular drift frequency is found to be the geometric mean of a particle\textquoterights angular drift velocities at noon and midnight. The radial diffusion coefficient D = (\textonehalf) (ΔL)\texttwosuperior/time is calculated as a function of the McIlwain parameter L and in terms of the spectral density of fluctuations in the stand-off distance of the magnetosphere boundary. Because the unperturbed drift trajectories are asymmetric, drift-resonant diffusion of particles is produced by spectral components at all harmonics of the drift frequency, although the first (fundamental) harmonic is the major contributor. Schulz, Michael; Eviatar, Aharon; Published by: Journal of Geophysical Research Published on: 05/1969 YEAR: 1969 DOI: 10.1029/JA074i009p02182 |
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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 λ \~ 71\textdegree and \~9 RE in the equatorial plane on the sunlit side, and at 7\textendash8 RE in the equatorial plane on the nightside. Beyond this, the unstable radiation zone extends out to the magnetosphere boundary and up to λ \~ 77\textdegree on the sunlit side, and out to 14\textendash15 RE on the nightside. The relatively rapid electron intensity variations with periods of 1\textendash7 days are essentially absent at distances less than that of the outer belt but are distinctly seen in the outer belt. In the unstable radiation zone the intensity of electrons with energies of the order of 105 ev changes by several times, and good correlation is observed with the increase in Kp. Analysis of the outer belt data shows that this belt is formed partly by electron diffusion into the magnetosphere (like the belt of protons with energies of 105\textendash107 ev) and partly by the simultaneous acceleration of electrons at various distances from the earth. A comparison of electron intensity changes with the solar activity cycle shows little or no correlation for electrons with Ee > 40 kev. The intensity of electrons with Ee > 500 kev has changed significantly; in 1964 it was 30 times lower than in 1959. The absence of significant dependence of the diffusion coefficients for electrons with E \~ 104\textendash105 ev on the phase of the solar activity cycle shows that the relatively weak magnetic disturbances that do not change with the phase of the cycle are of major importance in diffusion. This suggests that these magnetic disturbances appear at great distances from the sun because of the instabilities of plasma itself and, therefore, that they depend little on solar activity. Vernov, S.; Gorchakov, E.; Kuznetsov, S.; Logachev, Yu.; Sosnovets, E.; Stolpovsky, V.; Published by: Reviews of Geophysics Published on: 02/1969 YEAR: 1969 DOI: 10.1029/RG007i001p00257 |
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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 λ \~ 71\textdegree and \~9 RE in the equatorial plane on the sunlit side, and at 7\textendash8 RE in the equatorial plane on the nightside. Beyond this, the unstable radiation zone extends out to the magnetosphere boundary and up to λ \~ 77\textdegree on the sunlit side, and out to 14\textendash15 RE on the nightside. The relatively rapid electron intensity variations with periods of 1\textendash7 days are essentially absent at distances less than that of the outer belt but are distinctly seen in the outer belt. In the unstable radiation zone the intensity of electrons with energies of the order of 105 ev changes by several times, and good correlation is observed with the increase in Kp. Analysis of the outer belt data shows that this belt is formed partly by electron diffusion into the magnetosphere (like the belt of protons with energies of 105\textendash107 ev) and partly by the simultaneous acceleration of electrons at various distances from the earth. A comparison of electron intensity changes with the solar activity cycle shows little or no correlation for electrons with Ee > 40 kev. The intensity of electrons with Ee > 500 kev has changed significantly; in 1964 it was 30 times lower than in 1959. The absence of significant dependence of the diffusion coefficients for electrons with E \~ 104\textendash105 ev on the phase of the solar activity cycle shows that the relatively weak magnetic disturbances that do not change with the phase of the cycle are of major importance in diffusion. This suggests that these magnetic disturbances appear at great distances from the sun because of the instabilities of plasma itself and, therefore, that they depend little on solar activity. Vernov, S.; Gorchakov, E.; Kuznetsov, S.; Logachev, Yu.; Sosnovets, E.; Stolpovsky, V.; Published by: Reviews of Geophysics Published on: 02/1969 YEAR: 1969 DOI: 10.1029/RG007i001p00257 |
| 1966 |
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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 particle flux. Electron fluxes >40 kev and proton fluxes >120 kev observed on Explorers 14 and 12, respectively, obey this limit with occasional exceptions. Beyond L = 4, the fluxes are just below their limit, indicating that an unspecified acceleration source, sufficient to keep the trapped particles near their precipitation limit, exists. Limiting proton and electron fluxes are roughly equal, suggesting a partial explanation for the existence of larger densities of high-energy protons than of electrons. Observed electron pitch angle profiles correspond to a diffusion coefficient in agreement with observed lifetimes. The required equatorial whistler mode wide band noise intensity, 10-2γ, is not obviously inconsistent with observations and is consistent with the lifetime and with limiting trapped particle intensity. Published by: Journal Geophysical Research Published on: 01/1966 YEAR: 1966 DOI: 10.1029/JZ071i001p00001 |