Reproducing the energy-dependent structure of Earth's electron radiation belts during quiet times

0471702 - ÚFA 2017 US eng A - Abstrakt
Ripoll, J.-F. - Reeves, G. D. - Santolík, Ondřej - Cunningham, G. - Loridan, V. - Denton, M. - Kurth, W. S. - Turner, D. L. - Kletzing, C. - Henderson, M. G. - Ukhorskiy, S.
Reproducing the energy-dependent structure of Earth's electron radiation belts during quiet times.
AGU Fall Meeting. San Francisco: American Geophysical Union, 2016. SM21B-02.
[AGU Fall Meeting 2016. 12.12.2016-16.12.2016, San Francisco]
Institucionální podpora: RVO:68378289
Klíčová slova: radiation belts * slot region * energetic particles
Kód oboru RIV: BL - Fyzika plazmatu a výboje v plynech
https://agu.confex.com/agu/fm16/meetingapp.cgi/Paper/172554

We present and discuss 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 1 March 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. We will describe how the latter is generated from massively parallel computations of pitch angle diffusion at a scale never achieved in the past. The simulations reproduce Van Allen Probes observations for all energies and L shells (2–6) 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 transport and losses. We find that the characteristic energy-dependent structure of the radiation belts and slot region is dynamic and can be formed gradually in ~15 days, although the “S shape” can also be reproduced by assuming equilibrium conditions. But we will show that equilibrium states are usually not reachable as it requires very long times for most energy electrons and L-shells. The highest-energy electrons (E>300 keV) of the inner region of the outer belt (L~4–5) also constantly decay, demonstrating that hiss wave scattering affects the outer belt during times of extended plasmasphere. Through these simulations, we explain the full structure in energy and L shell of the belts and the slot formation by hiss scattering during storm recovery. We show the power and complexity of looking dynamically at the effects over all energies and L shells and the need for using data-driven and event-specific conditions.


Trvalý link: http://hdl.handle.net/11104/0269048