Influence of saturnian moons on saturn kilometric radiation

[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.

[1]  William Mendenhall,et al.  Introduction to probability and statistics (7th ed.) , 1986 .

[2]  M. L. Kaiser,et al.  Saturnian kilometric radiation: statistical properties and beam geometry , 1981, Nature.

[3]  M. L. Kaiser,et al.  The Cassini Radio and Plasma Wave Investigation , 2004 .

[4]  E. Bigg.  Influence of the Satellite Io on Jupiter's Decametric Emission , 1964, Nature.

[5]  M. L. Kaiser,et al.  Saturnian kilometric radiation: Source locations , 1982 .

[6]  Donald A. Gurnett,et al.  A Saturnian longitude system based on a variable kilometric radiation period , 2006 .

[7]  Christopher T. Russell,et al.  Modeling the size and shape of Saturn's magnetopause with variable dynamic pressure , 2006 .

[8]  J. Steinberg,et al.  Preliminary interpretation of Titan plasma interaction as observed by the Cassini Plasma Spectrometer: Comparisons with Voyager 1 , 2004 .

[9]  Travis W. Hill,et al.  The global plasma environment of Titan as observed by Cassini Plasma Spectrometer during the first two close encounters with Titan , 2005 .

[10]  Gábor Tóth,et al.  Global MHD simulations of Saturn's magnetosphere at the time of Cassini approach , 2005 .

[11]  A. C. Riddle,et al.  Voyager 1 Planetary Radio Astronomy Observations Near Jupiter , 1979, Science.

[12]  J. L. Green,et al.  Ray tracing of Jovian decametric radiation from southern and northern hemisphere sources: Comparison with Voyager observations , 1987 .

[13]  B. Burke,et al.  Observations of a variable radio source associated with the planet Jupiter , 1955 .

[14]  J. Richardson,et al.  Energetic nitrogen ions within the inner magnetosphere of Saturn , 2003 .

[15]  M. Desch,et al.  Phenomenology of magnetospheric radio emissions , 1983 .

[16]  M. Wilkinson.  Io-related Jovian decametric arcs , 1989 .

[17]  D. Gurnett,et al.  Titan's magnetospheric interaction , 2007 .

[18]  I. W. Christopher,et al.  Europa control of Jovian radio emission: A Galileo study , 2006 .

[19]  Peter Goldreich,et al.  IO, A JOVIAN UNIPOLAR INDUCTOR. , 1969 .

[20]  D. Grodent,et al.  Morphological differences between Saturn's ultraviolet aurorae and those of Earth and Jupiter , 2005, Nature.

[21]  David T. Young,et al.  Titan's near magnetotail from magnetic field and electron plasma observations and modeling: Cassini flybys TA, TB, and T3 , 2006 .

[22]  M. L. Kaiser,et al.  Radio Jupiter after Voyager: An overview of the planetary radio astronomy observations , 1981 .

[23]  D. Gurnett,et al.  Control of Saturn's kilometric radiation by Dione , 1981, Nature.

[24]  F. M. Neubauer,et al.  Nonlinear standing Alfvén wave current system at Io: Theory , 1980 .

[25]  William Mendenhall,et al.  Introduction to Probability and Statistics , 1961, The Mathematical Gazette.

[26]  M. Desch,et al.  Saturn's kilometric radiation: satellite modulation , 1981, Nature.

[27]  M. Goldstein,et al.  Physics of the Jovian Magnetosphere: Theories of radio emissions and plasma waves , 1983 .

[28]  B. Cecconi,et al.  An Earth-like correspondence between Saturn's auroral features and radio emission , 2005, Nature.

[29]  Edmond C. Roelof,et al.  Energetic ion acceleration in Saturn's magnetotail: Substorms at Saturn? , 2005 .

[30]  M. Dougherty,et al.  Comparisons between MHD model calculations and observations of Cassini flybys of Titan , 2006 .

[31]  W. Kurth,et al.  Saturn as a radio source , 1983 .

[32]  F. Genova,et al.  Source localization of Saturn kilometric radio emission , 1983 .

[33]  M. Desch,et al.  Planetary radio astronomy observations from voyager 1 near saturn. , 1981, Science.

[34]  William M. Farrell,et al.  A nightside source of Saturn's kilometric radiation: Evidence for an inner magnetosphere energy driver , 2005 .

[35]  F. Crary.  On the generation of an electron beam by Io , 1997 .

[36]  R. Ergun,et al.  Io‐related Jovian auroral arcs: Modeling parallel electric fields , 2003 .

[37]  D. Gurnett,et al.  Plasma waves near saturn: initial results from voyager 1. , 1981, Science.

[38]  M. Desch,et al.  Planetary Radio Astronomy Observations from Voyager 2 Near Saturn , 1979, Science.