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Barbosa 1993
Barbosa, D.D. (1993). Theory and observations of electromagnetic ion cyclotron waves in Saturn's inner magnetosphere. Journal of Geophysical Research 98: doi: 10.1029/93JA00476. issn: 0148-0227.

High-resolution Voyager 1 magnetic field observations of Saturn's inner magnetosphere are examined for the presence of ultralow frequency waves. Quasi-circular left-hand polarized transverse oscillations are found in the near-equatorial region of 5--7 RS with a wave period ~10 s and peak amplitude ~2 nT. The wave is identified as the electromagnetic oxygen cyclotron mode occurring at a frequency just below the O+ ion cyclotron frequency. The properties of the waves are very similar to those found by Smith and Tsurutani (1983) using Pioneer 11 data. A theoretical model of wave excitation based on gyroresonant coupling through a temperature anisotropy of O+ pickup ions is developed which accounts for the principal features of the wave spectrum. The theory and observations form the basis for the hypothesis that wave-particle interactions provide a level of scattering commensurate with the weak pitch angle diffusion regime but nonetheless one that regulates and maintains a constant thermal anisotropy of ions along the magnetic field. Arguments are also presented that O+ was the dominant thermal ion of the Dione-Tethys plasma torus at the time of the Pioneer 11 encounter the year previous to the Voyager 1 measurements. ¿ American Geophysical Union 1993

BACKGROUND DATA FILES

Abstract

Keywords
Magnetospheric Physics, Planetary magnetospheres, Magnetospheric Physics, MHD waves and instabilities, Magnetospheric Physics, Magnetosphere interactions with satellites and rings, Magnetospheric Physics, Energetic particles, trapped
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
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