Influence of Saturnian moons on Saturn kilometric radiation

Abstract

[1] Similar to past studies at Jupiter, we conduct an investigation of possible associations of radio emission occurrence probability with the orbital phases of Saturnian moons. We use a new definition of the Saturn longitude system (SLS) based on the results of Kurth et al. (2007). This paper presents results of our findings to date, sampling a large portion of the Radio and Plasma Wave Science (RPWS) instrument data over the frequency range 12 kHz < f < 16 MHz. We also investigate the intensity of Saturn kilometric radiation (SKR) as a function of the local time and subsolar longitude. When Titan is near a local time of midnight, there is a significant increase in the occurrence probability of SKR and a diminution of SKR when Titan is near local noon and afternoon. This indicates Titan may play a role in the process of substorm generation at Saturn perhaps due to its large plasma wake. Rhea displays a marginal orbital phase ''control'' of a subset of the SKR. In the past there have been conflicting reports of the absence of SKR emission at particular local times of Dione. We find no long-term, statistical influence of Dione on SKR occurrence probability. In addition, we find no significant statistical influence of Enceladus or Tethys on SKR occurrence probability.

The influence of Titan on Saturn kilometric radiation

“…In this paper we re-examine the occurrence probability of SKR emissions using a much larger database than the original study of Menietti et al (2007). We find the general conclusions of that study are confirmed.…”

“…Jackman et al (2009) have shown the association of SKR radio emissions and plasmoid-like structures indicative of Saturn substorms. However, Menietti et al (2007) found no significant association of SKR emission with the orbital location of Enceladus, despite the known significant source of water ions associated with this moon (cf. Porco et al, 2006).…”

“…The influence of Titan on the occurrence probability (OP) of Saturn Kilometric Radiation (SKR) has been reported by Menietti et al (2007). These authors suggested that Titan's presence in the magnetotail may contribute to the efficiency of reconnection and/or may increase mass loading onto reconnected field lines that map to the auroral region and active SKR generation sites.…”

Relationship between solar wind corotating interaction regions and the phasing and intensity of Saturn kilometric radiation bursts

“…The frequent detection of the "extra" bursts also affirms that parameters other than planetary rotation and the solar wind conditions could affect the occurrence of SKR bursts, e.g. the location of Saturn's moons (Menietti et al, 2007) which appear to influence the occurrence of tail reconnection events (Russell et al, 2008). Kurth et al (2005a) discussed in depth event 3 mentioned above (25-31 January 2004, not shown here), when the SKR detections became very weak, and stated that although Cassini RPWS detected very little SKR emission, the Unified Radio and Plasma wave experiment onboard the Ulysses spacecraft did measure SKR at the expected time.…”

Transport of Mass, Momentum and Energy in Planetary Magnetodisc Regions

“…At Saturn, analogous footpoint emissions from Enceladus have been observed (Pryor et al 2011). Footpoint emissions associated with Titan have yet to be identified, however the motion of Titan itself has the potential for modulating Saturn's kilometric radiation (SKR)-a phenomenon which is associated with the auroral process (Menietti et al 2007).…”