Is System IV a sideband of System III? The periodogram analyses of EUV and nKOM data
Dessler, Alexander J.
Master of Science
Jupiter's magnetosphere does not rigidly rotate with the System III angular rate. There is a corotation lag as a function of distance in the Jovian magnetosphere. The dominant rotational component, aside from System III, is a 3% longer period (System IV). System IV could be interpreted as a sideband of System III being amplitude-modulated by the 14.1-day period. Whether System IV is an independent Jovian coordinate or just a sideband is investigated in this thesis. The 9.64 hour period does not appear in periodogram analyses of EUV data from Voyager 2 and nKOM data from Voyager 1 and 2. Therefore, it is concluded that System IV is not a sideband and it is independent of System III. Through harmonic filtering, a signal with a 12.5-day period in the EUV data is found. It is suggested that the 12.5-day period is a solar-wind effect. (Abstract shortened with permission of autor.)