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| Titel |
The origin of Jupiter's outer radiation belt |
| VerfasserIn |
Emma Woodfield, Richard Horne, Sarah Glauert, John Menietti, Yuri Shprits |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250089877
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| Publikation (Nr.) |
 EGU/EGU2014-4090.pdf |
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| Zusammenfassung |
| The intense inner radiation belt at Jupiter (>50 MeV at 1.5 RJ) is the result of adiabatic
transport of electrons from further away from the planet; however, a seed population of high
energy electrons is still required at between 6 and 10 RJ with energies that exceed 1 MeV.
Here we test the hypothesis that the seed population outside the orbit of the moon Io could be
formed from a very soft energy spectrum due to particle injection processes, and acceleration
via whistler mode chorus waves. Using particle data as an initial condition at an
energy of 20 keV, we use the BAS radiation belt model to calculate the change in the
electron energy spectrum between 6.5 and 15 RJ due to whistler mode chorus waves.
Simulations show that the resulting energy spectrum lies very close to the empirical
Galileo Interim Radiation Electron model (GIRE) spectrum at Jupiter after less
than one day at 100 keV and less than 10 days at 1 MeV, suggesting that the seed
population could indeed be formed by wave-particle interactions. The results are
insensitive to the softness of the initial energy spectrum but do critically depend
on the value of the flux at the minimum energy boundary. Simulations for wave
acceleration and radial diffusion together show that the resulting spectrum remains close
to the GIRE spectrum but the radial profile of phase space density is smoothed. |
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