Jena 2013 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 4: Poster Session
EP 4.43: Poster
Dienstag, 26. Februar 2013, 11:15–12:45, Poster OG
Magnetic Field Fluctuations in Saturn’s Magnetosphere — •Michael von Papen1, Joachim Saur1, and Olga Alexandrova2 — 1Institut für Geophysik & Meteorologie, Universität zu Köln — 2Observatoire de Paris, LESIA, Meudon, France
In the framework of turbulence, we analyze the statistical properties of magnetic field fluctuations measured by the Cassini spacecraft inside Saturn’s plasma sheet. In the power spectra of the fluctuations we identify two power-law spectral ranges seperated by a spectral break around ion gyro-frequencies of O+ and H+. The spectral indices of the low frequency power-law are found to be between 5/3 (for fully developed cascades) and 1 (during energy input on the corresponding scales). Above the spectral break there is a constant power-law with mean spectral index ∼2.5 indicating a permament turbulent cascade in the kinetic range. An increasing non-gaussian probability density with frequency indicates the build-up of intermittency. Correlations of plasma parameters with the spectral indices are examined and it is found that the power-law slope depends strongly on background magnetic field strength and plasma beta.