A Rotating Azimuthally Distributed Auroral Current System on Saturn Revealed by the Cassini Spacecraft
- 1 October 2021
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal Letters
- Vol. 919 (2), L25
- https://doi.org/10.3847/2041-8213/ac26b5
Abstract
Stunning aurorae are mainly produced when accelerated electrons travel along magnetic field lines to collide with the atmosphere. The motion of electrons often corresponds to the evolution of a magnetic field-aligned current system. In the terrestrial magnetosphere, the current system is formed at the night-side sector, and thus produces an auroral bulge at night. Due to the different energy sources between Saturn and the Earth, it is expected that their auroral current systems are fundamentally different, although the specific auroral driver at Saturn is poorly understood. Using simultaneous measurements of the aurora, particles, magnetic fields, and energetic neutral atoms, we reveal that a chain of paired currents, each of which includes a downward and an upward current branch, is formed in Saturn's magnetosphere, which generates separated auroral patches. These findings inform similar auroral current structures between the Earth and Saturn, while the difference is that Saturn's unique mass and energy sources lead to a rotational characteristic.Keywords
This publication has 38 references indexed in Scilit:
- Auroral signatures of multiple magnetopause reconnection at SaturnGeophysical Research Letters, 2013
- Cassini observations of a Kelvin‐Helmholtz vortex in Saturn's outer magnetosphereJournal of Geophysical Research, 2010
- A model of force balance in Saturn's magnetodiscMonthly Notices of the Royal Astronomical Society, 2010
- Recurrent energization of plasma in the midnight-to-dawn quadrant of Saturn's magnetosphere, and its relationship to auroral UV and radio emissionsPlanetary and Space Science, 2009
- Timing and localization of ionospheric signatures associated with substorm expansion phase onsetJournal of Geophysical Research, 2009
- Intensification of preexisting auroral arc at substorm expansion phase onset: Wave‐like disruption during the first tens of secondsGeophysical Research Letters, 2008
- Saturn's magnetodisc current sheetJournal of Geophysical Research, 2008
- Potential Plasma Instabilities For Substorm Expansion OnsetsSpace Science Reviews, 2004
- Auroral hiss, Z mode radiation, and auroral kilometric radiation in the polar magnetosphere: DE 1 observationsJournal of Geophysical Research, 1983
- Satellite studies of magnetospheric substorms on August 15, 1968: 9. Phenomenological model for substormsJournal of Geophysical Research, 1973