第七届青年地学论坛

Banded structures observed in energetic particle spectrograms in the Earth’s inner ra-diation belt and slot region, i.e., “zebra stripes”, have been resolved also in the Satur-nian magnetosphere with Cassini. This paper implements a large-scale statistical anal-ysis of Saturnian zebra stripe properties in association to the noon to midnight electricfield of the inner magnetosphere, to which the stripes’ origin was recently established.Cassini has detected zebra stripes extending between L-shells (L) of 5 to 9 for more thanhalf of the orbits that crossed inward of L=9. The amplitude of the stripes is15−20%on average above the background differential energy flux, and their age is estimated tobe 20-60 hours. The regular observation of zebra stripes suggests that a magnetosphericvariability over time scales comparable to their estimated lifetime (days). The flux-enhancedstripes are traced back to the dayside, preferentially from post-noon, indicating an elec-tric field orientation from post-noon to post-midnight. Our results further suggest thatthe electric field’s offset from the noon-midnight line subject to both L-shell and tem-poral dependencies, confirming the previous unverified variabilit

土星 磁层 辐射带