Biblio

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Filters: Author is Loridan, V.  [Clear All Filters]
2018
Authors: Ripoll ‐F., Loridan V., Denton M. H., Cunningham G., Reeves G., et al.
Title: Observations and Fokker‐Planck simulations of the L‐shell, energy, and pitch‐angle structure of Earth’s electron radiation belts during quiet times
Abstract: The evolution of the radiation belts in L‐shell (L), energy (E), and equatorial pitch‐angle (α0) is analyzed during the calm 11‐day interval (March 4 –March 15) following the March 1 storm 2013. Magnetic Electron and Ion Spectrometer (MagEIS) observations from Van Allen Probes are interpreted alongside 1D and 3D Fokker‐Planck simulations combined with consistent event‐driven scattering modeling from whistler mode hiss waves. Three (L, E, α0)‐regions persist through 11 days of hiss wave scattering; the pitch‐angle dependent inner belt core (L~<2.2 and E<700 keV), pitch‐angle homogeneous outer belt low‐energy core (L>~5 and E~<100 keV), and a distinct pocket of electrons (L~[4.5, 5.5] and E~[0.7, 2] MeV). The pitch‐angle homogeneous outer belt is explained by the diff. . .
Date: 12/2018 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1029/2018JA026111 Available at: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JA026111
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2017
Authors: Ripoll J.-F., Santol?k O., Reeves G., Kurth W S, Denton M., et al.
Title: Effects of whistler mode hiss waves in March 2013
Abstract: We present simulations of the loss of radiation belt electrons by resonant pitch angle diffusion caused by whistler mode hiss waves for March 2013. Pitch angle diffusion coefficients are computed from the wave properties and the ambient plasma data obtained by the Van Allen Probes with a resolution of 8 hours and 0.1 L-shell. Loss rates follow a complex dynamic structure, imposed by the wave and plasma properties. Hiss effects can be strong, with minimum lifetimes (of ~1 day) moving from energies of ~100 keV at L~5 up to ~2 MeV at L~2, and stop abruptly, similarly to the observed energy-dependent inner belt edge. Periods when the plasmasphere extends beyond L~5 favor long-lasting hiss losses from the outer belt. Such loss rates are embedded in a reduced Fokker-Planck code and validated aga. . .
Date: 06/2017 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2017JA024139 Available at: http://onlinelibrary.wiley.com/doi/10.1002/2017JA024139/full
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2016
Authors: Ripoll J. F., Reeves G., Cunningham G., Loridan V., Denton M., et al.
Title: Reproducing the observed energy-dependent structure of Earth's electron radiation belts during storm recovery with an event-specific diffusion model
Abstract: We present dynamic simulations of energy-dependent losses in the radiation belt " slot region" and the formation of the two-belt structure for the quiet days after the March 1st storm. The simulations combine radial diffusion with a realistic scattering model, based data-driven spatially and temporally-resolved whistler mode hiss wave observations from the Van Allen Probes satellites. The simulations reproduce Van Allen Probes observations for all energies and L-shells (2 to 6) including (a) the strong energy-dependence to the radiation belt dynamics (b) an energy-dependent outer boundary to the inner zone that extends to higher L-shells at lower energies and (c) an " S-shaped" energy-dependent inner boundary to the outer zone that results from the competition between diffusive radial tran. . .
Date: 05/2016 Publisher: Geophysical Research Letters DOI: 10.1002/2016GL068869 Available at: http://doi.wiley.com/10.1002/2016GL068869
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Authors: Ripoll J. F., Loridan V., Cunningham G. S., Reeves G D, and Shprits Y Y
Title: On the Time Needed to Reach an Equilibrium Structure of the Radiation Belts
Abstract: In this study, we complement the notion of equilibrium states of the radiation belts with a discussion on the dynamics and time needed to reach equilibrium. We solve for the equilibrium states obtained using 1D radial diffusion with recently developed hiss and chorus lifetimes at constant values of Kp = 1, 3 and 6. We find that the equilibrium states at moderately low Kp, when plotted vs L-shell (L) and energy (E), display the same interesting S-shape for the inner edge of the outer belt as recently observed by the Van Allen Probes. The S-shape is also produced as the radiation belts dynamically evolve toward the equilibrium state when initialized to simulate the buildup after a massive dropout or to simulate loss due to outward diffusion from a saturated state. Physically, this shape,. . .
Date: 06/2016 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2015JA022207 Available at: http://doi.wiley.com/10.1002/2015JA022207
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