Source Region and Growth Analysis of Narrowband Z-mode Emission at Saturn

Wednesday, 16 December 2015
Poster Hall (Moscone South)
John Douglas Menietti1, David Pisa2, Ondrej Santolik1,3, Shengyi Ye1, Christopher Stephen Arridge4 and Andrew J Coates5, (1)University of Iowa, Physics and Astronomy, Iowa City, IA, United States, (2)University of Iowa, Iowa City, IA, United States, (3)Institute of Atmospheric Physics, CAS, Prague, Czech Republic, (4)University College London, Mullard Space Science Laboratory, London, United Kingdom, (5)University College London, Centre for Planetary Sciences (at UCL/Birkbeck), London, United Kingdom
Z-mode intensity levels can be significant in the lower density region near the inner edge of the Enceladus torus at Saturn, where these waves may resonate with electrons at MeV energies. The source mechanism of this emission, which is narrow banded and most intense near 5 kHz, is not yet well understood. We survey the Cassini Radio and Plasma Wave Science (RPWS) data to isolate several probable source regions. Electron phase space distributions are obtained from the Cassini Electron Spectrometer (ELS), a part of the Cassini Plasma Spectrometer (CAPS) investigation. These data are analyzed in seeking the wave source mechanism, free energy source and growth rate of Z-mode observations. We present the first results of our analysis.