The impact of geocoronal density on ring current development

Ilie, R.; Skoug, R. M.; Funsten, H. O.; Liemohn, Michael W.; Bailey, Justin J.; Gruntman, M.

doi:10.1016/j.jastp.2012.03.010

Cited by 52 publications

(62 citation statements)

References 41 publications

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“…Based on the estimates presented in Ilie et al . [], the lifetimes of >200 keV protons are >3 h at L > 2. Thus, Van Allen Probes should also observe proton injections at low L corresponding to those of the electrons if SPELLS were due to enhanced localized convection.…”

Section: Discussionmentioning

confidence: 99%

Investigating the source of near‐relativistic and relativistic electrons in Earth's inner radiation belt

et al. 2017

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Using observations from NASA's Van Allen Probes, we study the role of sudden particle enhancements at low L shells (SPELLS) as a source of inner radiation belt electrons. SPELLS events are characterized by electron intensity enhancements of approximately an order of magnitude or more in less than 1 day at L < 3. During quiet and average geomagnetic conditions, the phase space density radial distributions for fixed first and second adiabatic invariants are peaked at 2 < L < 3 for electrons ranging in energy from ~50 keV to ~1 MeV, indicating that slow inward radial diffusion is not the dominant source of inner belt electrons under quiet/average conditions. During SPELLS events, the evolution of electron distributions reveals an enhancement of phase space density that can exceed 3 orders of magnitude in the slot region and continues into the inner radiation belt, which is evidence that these events are an important—and potentially dominant—source of inner belt electrons. Electron fluxes from September 2012 through February 2016 reveal that SPELLS occur frequently (~2.5/month at 200 keV), but the number of observed events decreases exponentially with increasing electron energy for ≥100 keV. After SPELLS events, the slot region reforms due to slow energy‐dependent decay over several day time scales, consistent with losses due to interactions with plasmaspheric hiss. Combined, these results indicate that the peaked phase space density distributions in the inner electron radiation belt result from an “on/off,” geomagnetic‐activity‐dependent source from higher radial distances.

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Section: Discussionmentioning

confidence: 99%

Investigating the source of near‐relativistic and relativistic electrons in Earth's inner radiation belt

et al. 2017

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“…These include charge exchange, precipitation into the atmosphere due to wave-particle interactions, and drift losses (e.g. Hamilton et al 1988;Kistler et al 1989;Daglis et al 1999;Ebihara and Ejiri 2002;Ilie et al 2012). Coulomb interactions may also play a role at low energies (Fok et al 1993).…”

Section: Sawtooth Eventsmentioning

confidence: 99%

Circulation of Heavy Ions and Their Dynamical Effects in the Magnetosphere: Recent Observations and Models

et al. 2014

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Knowledge of the ion composition in the near-Earth's magnetosphere and plasma sheet is essential for the understanding of magnetospheric processes and instabilities. The presence of heavy ions of ionospheric origin in the magnetosphere, in particular oxygen (O + ), influences the plasma sheet bulk properties, current sheet (CS) thickness and its structure. It affects reconnection rates and the formation of Kelvin-Helmholtz instabilities. This has profound consequences for the global magnetospheric dynamics, including geomagnetic storms and substorm-like events. The formation and demise of the ring current and the radiation belts are also dependent on the presence of heavy ions. In this review we cover recent advances in observations and models of the circulation of heavy ions in the magne- tosphere, considering sources, transport, acceleration, bulk properties, and the influence on the magnetospheric dynamics. We identify important open questions and promising avenues for future research.

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“…Based on in-situ observations by Geotail/EPIC, Keika (2005) estimate that a minimum of 23 % of the total ring current fast decay is due to dayside ion outflow, even in the case of a sudden northward turning of the interplanetary magnetic field, which causes a sudden decrease in the convection electric field. However, increased convection will push particles closer to the Earth where charge exchange processes can contribute to the rapid decay of the ring current (Ilie et al 2013). The spatial configuration of the open drift paths and how deep the particles penetrate into the inner magnetosphere determines whether charge exchange makes a significant contribution to the ring current losses as the ions drift through the inner magnetosphere to the dayside magnetopause region.…”

Section: Advective Lossmentioning

confidence: 99%

The Earth: Plasma Sources, Losses, and Transport Processes

et al. 2015

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This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et al., Magnetospheric Plasma Sources and Losses, 1999) are addressed.

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The impact of geocoronal density on ring current development

Cited by 52 publications

References 41 publications

Investigating the source of near‐relativistic and relativistic electrons in Earth's inner radiation belt

Investigating the source of near‐relativistic and relativistic electrons in Earth's inner radiation belt

Circulation of Heavy Ions and Their Dynamical Effects in the Magnetosphere: Recent Observations and Models

The Earth: Plasma Sources, Losses, and Transport Processes

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