Particle diffusion in the geomagnetosphere: Comparison of estimates from measurements of magnetic and electric field fluctuations

Lanzerotti, L. J.; Wolfe, A.

doi:10.1029/ja085ia05p02346

Cited by 19 publications

(12 citation statements)

References 19 publications

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“…5.The electric spectral density of our model storm is extremely variable and leads to a highly irregular variation of radial-diffusion coefficients D~"L obtained from our simulations with f..t. The variation is similar to that found from observational data in spectral densities extracted by Lanzerotti and Wolfe [1980] and thus may be realistic. [ef.…”

Section: Discussionsupporting

confidence: 72%

See 1 more Smart Citation

Stormtime transport of ring current and radiation belt ions

Chen¹,

Schulz²,

Lyons³

et al. 1993

J. Geophys. Res.

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TECHNOLOGY OPERATIONSThe Aerospace Corporation functions as an "architect-engineer" for national security programs, specializing in advanced military space systems_ The Corporation's Technology Operations supports the effective and timely development and operation of national security systems through scientific research and the application of advanced technology. Vital to the success of the Corporation is the technical staffs wide-ranging expertise and its ability to stay abreast of new technological developments and program support issues associated with rapidly evolving space systems. Contributing capabilities are provided by these individual Technology Centers:Electronics Technology Center: Microelectronics, solid-state device physics, VLSI reliability, compound semiconductors, radiation hardening, data storage technologies, infrared detector devices and testing; electro-optics, quantum electronics, solid-state lasers, optical propagation and communications; cw and pulsed chemical laser development, optical resonators, beam control, atmospheric propagation, and laser effects and countermeasures; atomic frequency standards, applied laser spectroscopy, laser chemistry, laser optoelectronics, phase conjugation and coherent imaging, solar cell physics, battery electrochemistry, battery testing and evaluation.Mechanics and Materials Technology Center: Evaluation and characterization of new materials: metals, alloys, ceramics, polymers and their composites, and new forms of carbon; development and analysis of thin films and deposition techniques; nondestructive evaluation, component failure analysis and reliability; fracture mechanics and stress corrosion; development and evaluation of hardened components; analysis and evaluation of materials at cryogenic and elevated temperatures; launch vehicle and reentry fluid mechanics, heat transfer and flight dynamics; chemical and electric propulsion; spacecraft structural mechanics, spacecraft survivability and vulnerability assessment; contamination, thermal and structural control; high temperature thermomechanics, gas kinetics and radiation; lubrication and surface phenomena.Space and Environment Technology Center: Magnetospheric, auroral and cosmic ray physics, wave-particle interactions, magnetospheric plasma waves; atmospheric and ionospheric physics, density and composition of the upper atmosphere, remote sensing using atmospheric radiation; solar physics, infrared astronomy, infrared signature analysis; effects of solar activity, magnetic storms and nuclear explosions on the earth's atmosphere, ionosphere and magnetosphere; effects of electromagnetic and particulate radiations on space systems; space instrumentation; propellant chemistry, chemical dynamics, environmental chemistry, trace detection; atmospheric chemical reactions, atmospheric optics, light scattering, state-specific chemical reactions and radiative signatures of missile plumes, and sensor out-offield-of-view rejection. Author (revised) ABS: This is an investigation of stormtime particle transport tha...

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Section: Discussionsupporting

confidence: 72%

“…Its most notable feature is an extreme lack of smoothness [cf. Lanzerotti and Wolfe, 1980). The spectrum is so variable because the impulse onsets (i) in any individual storm modeled by (4) occur at specific times.…”

Section: In View Of the Good Agreement Between Values Of L(t*)mentioning

confidence: 99%

Stormtime transport of ring current and radiation belt ions

Chen¹,

Schulz²,

Lyons³

et al. 1993

J. Geophys. Res.

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“…One uncertainty arises from the complete ignorance of the azimuthal dependence of the fluctuations as discussed above. Lanzerotti and Wolfe [1980] point out that single point measurements of magnetic or electric field fluctuations will lead to an overestimate of radial diffusion rates because a certain fraction of power at the particle drift frequency will reside in higher frequency spatial components. There are alternatives to the azimuthal dependence assumed in this study, and it is not clear how these various models would affect the resulting D LL E .…”

Section: Discussionmentioning

confidence: 99%

“…There are several significant uncertainties involved with the assumptions necessitated by single point measurements. Lanzerotti and Wolfe [1980] concluded their study comparing empirical estimates of D LL E and D LL M by stating that, “Substantial more work in comparing, for the same time intervals, electric and magnetic field fluctuations in space, on the ground, and at different latitudes is required in order to ultimately completely understand the temporal and spatial dependencies of the third‐invariant‐violating processes in the earth's magnetosphere.” Nearly a quarter of a century later, we find ourselves in much the same situation. This study has taken a step forward by estimating the D LL E based on single point measurements.…”

Section: Discussionmentioning

confidence: 99%

CRRES electric field power spectra and radial diffusion coefficients

et al. 2005

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[1] Combined Release and Radiation Effects Satellite (CRRES) Electric Field Instrument (EFI) data are used to determine the electric field power spectral density as a function of L and Kp over the frequency range 0.2 to 15.9 mHz. The power at each frequency is fit to the function P(L, Kp) = a L b exp(cKp). Assuming a purely electrostatic field and making several other assumptions regarding the azimuthal dependence of the field fluctuations, a Kp-dependent radial diffusion coefficient D LL E is computed from the power spectra. The model average D LL E for high activity (Kp = 6) are between 1 to 2 orders of magnitude larger than that for low activity (Kp = 1), dependent upon L and first invariant.

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“…The spectra of the fluctuations of magnetic and electric fields in the range of ULF were also obtained from satellites (e.g., Lanzerotti et al, 1978;Holzworth and Mozer, 1979;Lanzerotti and Wolfe, 1980;Ali et al, 2015). The results of these estimates of D LL differ from each other by several orders of magnitude.…”

Section: Introductionmentioning

confidence: 99%

Deduction of the rates of radial diffusion of protons from the structure of the Earth's radiation belts

Kovtyukh

2016

Ann. Geophys.

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Abstract. From the data on the fluxes and energy spectra of protons with an equatorial pitch angle of α 0 ≈ 90 • during quiet and slightly disturbed (Kp ≤ 2) periods, I directly calculated the value D LL , which is a measure of the rate of radial transport (diffusion) of trapped particles. This is done by successively solving the systems (chains) of integrodifferential equations which describe the balance of radial transport/acceleration and ionization losses of low-energy protons of the stationary belt. This was done for the first time. For these calculations, I used data of International SunEarth Explorer 1 (ISEE-1) for protons with an energy of 24 to 2081 keV at L = 2-10 and data of Explorer-45 for protons with an energy of 78.6 to 872 keV at L = 2-5. Ionization losses of protons (Coulomb losses and charge exchange) were calculated on the basis of modern models of the plasmasphere and the exosphere. It is shown that for protons with µ from ∼ 0.7 to ∼ 7 keV nT −1 at L≈ 4.5-10, the functions of D LL can be approximated by the following equivalent expressions:, where f d is the drift frequency of the protons (in mHz), D LL is measured in s −1 , E is measured in kiloelectronvolt and µ is measured in kiloelectronvolt per nanotesla. These results are consistent with the radial diffusion of particles under the action of the electric field fluctuations (pulsations) in the range of Pc6 and contradict the mechanism of the radial diffusion of particles under the action of sudden impulses (SIs) of the magnetic field and also under the action of substorm impulses of the electric field. During magnetic storms D LL increases, and the expressions for D LL obtained here can change completely.

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Particle diffusion in the geomagnetosphere: Comparison of estimates from measurements of magnetic and electric field fluctuations

Cited by 19 publications

References 19 publications

Stormtime transport of ring current and radiation belt ions

Stormtime transport of ring current and radiation belt ions

CRRES electric field power spectra and radial diffusion coefficients

Deduction of the rates of radial diffusion of protons from the structure of the Earth's radiation belts

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