Access of energetic particles to storm time ring current through enhanced radial diffusion

Journal Article · Mon May 01 00:00:00 EDT 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JA094iA05p05491· OSTI ID:5831304

Lyons, L R; Schulz, M ^[1]

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1. Aerospace Corp., Los Angeles, CA (USA)

Magnetic storms are distinguishable from other periods of geomagnetic activity by the injection of trapped electrons and ions to the 2{approx lt} L {approx lt} 4 region. It has been proposed previously that this injection results from an inward displacement of the preexisting trapped-particle population by enhanced storm time electric fields. However, high-energy ({approx gt} 40 keV) ring-current particles have drift periods that are typically shorter than the time of the main-phase development, and so the direct radial transport of these particles is restricted. The authors propose here that the transport of {approx gt} 40 keV particles into the storm time ring current can result from enhanced stochastic radial transport driven by fluctuating electric fields during a storm's main phase. They estimate the effects of such electric fields by applying radial-diffusion theory, assuming a preexisting trapped-particle population as the initial conditions, and they demonstrate the feasibility of explaining observed flux increases of {approx gt} 40-keV particles at L{approx lt} 4 by enhanced radial diffusion. It is necessary that new particles be injected near the outer boundary of the trapping region so as to maintain the fluxes there as an outer boundary condition, and they estimate that the {approx gt} 40-keV portion of the storm time ring current at L {approximately} 3 consists of about 50% preexisting and about 50% new particles. They thus find that formation of the storm time ring current may be explainable via a combination of direct radial transport at energies {approx lt} 40 keV and diffusive radial transport at higher energies.

• OSTI ID: 5831304
• Journal Information: Journal of Geophysical Research; (USA), Vol. 94:A5; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MAGNETIC STORMS
TRAPPED ELECTRONS
TRAPPED PROTONS
CHARGED-PARTICLE TRANSPORT
COMPARATIVE EVALUATIONS
DIFFUSION
ELECTRIC FIELDS
GEOMAGNETIC FIELD
STOCHASTIC PROCESSES
BARYONS
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
LEPTONS
MAGNETIC FIELDS
NUCLEONS
PROTONS
RADIATION TRANSPORT
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena