Advertisement

A Brief Review of Ultraviolet Auroral Emissions on Giant Planets

  • Denis GrodentEmail author
Chapter
Part of the Space Sciences Series of ISSI book series (SSSI, volume 50)

Abstract

The morphologies of the ultraviolet auroral emissions on the giant gas planets, Jupiter and Saturn, have conveniently been described with combinations of a restricted number of basic components. Although this simplified view is very handy for a gross depiction of the giant planets’ aurorae, it fails to scrutinize the diversity and the dynamics of the actual features that are regularly observed with the available ultraviolet imagers and spectrographs. In the present review, the typical morphologies of Jupiter and Saturn’s aurorae are represented with an updated and more accurate set of components. The use of sketches, rather than images, makes it possible to compile all these components in a single view and to put aside ultraviolet imaging technical issues that are blurring the emission sources, thus preventing one from disentangling the different auroral signatures. The ionospheric and magnetospheric processes to which these auroral features allude can then be more easily accounted. In addition, the use of components of the same kind for both planets may help to put forward similarities and differences between Jupiter and Saturn. The case of the ice giants Uranus and Neptune is much less compelling since their weak auroral emissions are very poorly documented and one can only speculate about their origin. This review presents a current perspective that will inevitably evolve in the future, especially with upcoming observing campaigns and forthcoming missions like Juno.

Keywords

Jupiter Saturn Uranus Neptune Giant planets Aurora Ultraviolet Magnetosphere 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. D.J. Andrews, A.J. Coates, S.W.H. Cowley, M.K. Dougherty, L. Lamy, G. Provan, P. Zarka, Magnetospheric period oscillations at Saturn: comparison of equatorial and high-latitude magnetic field periods with north and south Saturn kilometric radiation periods. J. Geophys. Res. 115, A12252 (2010). doi: 10.1029/2010JA015666 ADSGoogle Scholar
  2. C.S. Arridge et al., Uranus Pathfinder: exploring the origins and evolution of ice giant planets. Exp. Astron. 33, 753–791 (2012). doi: 10.1007/s10686-011-9251-4 ADSCrossRefGoogle Scholar
  3. S.V. Badman, E.J. Bunce, J.T. Clarke, S.W.H. Cowley, J.-C. Gérard, D. Grodent, S.E. Milan, Open flux estimates in Saturn’s magnetosphere during the January 2004 Cassini-HST campaign, and implications for reconnection rates. J. Geophys. Res. 110, A11216 (2005). doi: 10.1029/2005JA011240 ADSCrossRefGoogle Scholar
  4. S.V. Badman, S.W.H. Cowley, J.-C. Gérard, D. Grodent, A statistical analysis of the location and width of Saturn’s southern auroras. Ann. Geophys. 24, 3533–3545 (2006). doi: 10.5194/angeo-24-3533-2006 ADSCrossRefGoogle Scholar
  5. S.V. Badman, A. Masters, H. Hasegawa, M. Fujimoto, A. Radioti, D. Grodent, N. Sergis, M.K. Dougherty, A.J. Coates, Bursty magnetic reconnection at Saturn’s magnetopause. Geophys. Res. Lett. 40, 1027–1031 (2013). doi: 10.1002/grl.50199 ADSCrossRefGoogle Scholar
  6. S.V. Badman, G. Branduardi-Raymont, M. Galand, S.L.G. Hess, N. Krupp, L. Lamy, H. Melin, C. Tao, Auroral processes at the giant planets: energy deposition, emission mechanisms, morphology and spectra. Space Sci. Rev. (2014). doi: 10.1007/s11214-014-0042-x (this issue) Google Scholar
  7. F. Bagenal, A. Adriani, F. Allegrini, S.J. Bolton, B. Bonfond, E.J. Bunce, J.E.P. Connerney, S.W.H. Cowley, R.W. Ebert, G.R. Gladstone, C.J. Hansen, W.S. Kurth, S.M. Levin, B.H. Mauk, D.J. McComas, C.P. Paranicas, D. Santos-Costas, R.M. Thorne, P. Valek, J.H. Waite, P. Zarka, Magnetospheric science objectives of the Juno mission. Space Sci. Rev. (2014). doi: 10.1007/s11214-014-0036-8 Google Scholar
  8. B. Bhattacharya, R.M. Thorne, D.J. Williams, On the energy source for diffuse jovian auroral emissivity. Geophys. Res. Lett. 14, 2751–2754 (2001) ADSCrossRefGoogle Scholar
  9. S.J. Bolton (The Juno Science Team), The Juno mission, in International Astronomical Union, ed. by C. Barbieri et al.. Proceedings IAU Symposium, vol. 269 (Cambridge University Press, Cambridge, 2010). doi: 10.1017/S1743921310007313 Google Scholar
  10. B. Bonfond, D. Grodent, J.-C. Gérard, A. Radioti, J. Saur, S. Jacobsen, UV Io footprint leading spot: a key feature for understanding the UV Io footprint multiplicity? Geophys. Res. Lett. 35, L05107 (2008). doi: 10.1029/2007GL032418 ADSCrossRefGoogle Scholar
  11. B. Bonfond, D. Grodent, J.-C. Gérard, A. Radioti, V. Dols, P.A. Delamere, J.T. Clarke, The Io UV footprint: location, inter-spot distances and tail vertical extent. J. Geophys. Res. 114, A07224 (2009). doi: 10.1029/2009JA014312 ADSCrossRefGoogle Scholar
  12. B. Bonfond, The 3-D extent of the Io UV footprint on Jupiter. J. Geophys. Res. 115, A09217 (2010). doi: 10.1029/2010JA015475 ADSCrossRefGoogle Scholar
  13. B. Bonfond, M.F. Vogt, J.-C. Gérard, D. Grodent, A. Radioti, V. Coumans, Quasi-periodic polar flares at Jupiter: a signature of pulsed dayside reconnections? Geophys. Res. Lett. 38, L02104 (2011). doi: 10.1029/2010GL045981 ADSCrossRefGoogle Scholar
  14. B. Bonfond, D. Grodent, J.-C. Gérard, T. Stallard, J.T. Clarke, M. Yoneda, A. Radioti, J. Gustin, Auroral evidence of Io’s control over the magnetosphere of Jupiter. Geophys. Res. Lett. 39, L01105 (2012a). doi: 10.1029/2011GL050253 ADSCrossRefGoogle Scholar
  15. B. Bonfond, When moons create aurora: the satellite footprints on giant planets in auroral phenomenology and magnetospheric processes: earth and other planets, in Geophys. Monogr. Ser., vol. 197, ed. by A. Keiling, et al. (AGU, Washington, 2012b, to appear). pp. 133–140. doi: 10.1029/2011GM001169 Google Scholar
  16. B. Bonfond, S. Hess, F. Bagenal, J.-C. Gérard, D. Grodent, A. Radioti, J. Gustin, J.T. Clarke, The multiple spots of the Ganymede auroral footprint. Geophys. Res. Lett. 40, 4977–4981 (2013). doi: 10.1002/grl.50989 ADSCrossRefGoogle Scholar
  17. G. Branduardi-Raymont, R.F. Elsner, M. Galand, D. Grodent, T.E. Cravens, P. Ford, G.R. Gladstone, J.H. Waite Jr., Spectral morphology of the X-ray emission from Jupiter’s aurorae. J. Geophys. Res. 113, A02202 (2008). doi: 10.1029/2007JA012600 ADSCrossRefGoogle Scholar
  18. A.L. Broadfoot et al., Extreme ultraviolet observations from Voyager 1 encounter with Jupiter. Science 204, 979–982 (1979). doi: 10.1126/science.204.4396.979 ADSCrossRefGoogle Scholar
  19. A.L. Broadfoot et al., Extreme ultraviolet observations from Voyager 1 encounter with Saturn. Science 212, 206–211 (1981). doi: 10.1126/science.212.4491.206 ADSCrossRefGoogle Scholar
  20. A.L. Broadfoot et al., Ultraviolet spectrometer observations of Uranus. Science 233(4759), 74–79 (1986). doi: 10.1126/science.233.4759.74 ADSCrossRefGoogle Scholar
  21. A.L. Broadfoot et al., Ultraviolet spectrometer observations of Neptune and Triton. Science 246(4936), 1459–1466 (1989). doi: 10.1126/science.246.4936.1459 ADSCrossRefGoogle Scholar
  22. E.J. Bunce, S.W.H. Cowley, S.E. Milan, Interplanetary magnetic field control of Saturn’s polar cusp aurora. Ann. Geophys. 23, 1405–1431 (2005) ADSCrossRefGoogle Scholar
  23. E.J. Bunce et al., Origin of Saturn’s aurora: simultaneous observations by Cassini and the Hubble space telescope. J. Geophys. Res. 113, A09209 (2008). doi: 10.1029/2008JA013257 ADSGoogle Scholar
  24. E.J. Bunce, D. Grodent, S.L. Jinks, C.S. Arridge, D.J. Andrews, S.V. Badman, S.W.H. Cowley, M.K. Dougherty, W.S. Kurth, D.G. Mitchell, G. Provan, Cassini nightside observations of the oscillatory motion of Saturn’s northern auroral oval. J. Geophys. Res. (2014) (in press). doi: 10.1029/2013JA019527 Google Scholar
  25. T. Chust, A. Roux, W.S. Kurth, D.A. Gurnett, M.G. Kivelson, K.K. Khurana, Are Io’s Alfvén wings filamented? Galileo observations. Planet. Space Sci. 53, 395–412 (2005). doi: 10.1016/j.pss.2004.09.021 ADSCrossRefGoogle Scholar
  26. J.T. Clarke et al., Ultraviolet emissions from the magnetic footprints of Io, Ganymede and Europa on Jupiter. Nature 415, 997–1000 (2002) ADSCrossRefGoogle Scholar
  27. J.T. Clarke, D. Grodent, S.W.H. Cowley, E.J. Bunce, P. Zarka, J.E.P. Connerney, T. Satoh, Jupiter’s aurora, in Jupiter: The Planet, Satellites and Magnetosphere (Cambridge Univ. Press, Cambridge, 2004), pp. 639–670 Google Scholar
  28. J.T. Clarke et al., Morphological differences between Saturn’s ultraviolet aurorae and those of earth and Jupiter. Nature 433, 717–719 (2005). doi: 10.1038/nature03331 ADSCrossRefGoogle Scholar
  29. J.T. Clarke, S. Wannawichian, N. Hernandez, B. Bonfond, J.-C. Gérard, D. Grodent, Detection of auroral emissions from Callisto’s magnetic footprint at Jupiter. Poster presented at the EPSC-DPS Joint Meeting 2011, EPSC abstracts, vol. 6, EPSC-DPS2011-1468 (2011) Google Scholar
  30. S.W.H. Cowley, E.J. Bunce, Origin of the main auroral oval in Jupiter’s coupled magnetosphere-ionosphere system. Planet. Space Sci. 49, 1067–1088 (2001) ADSCrossRefGoogle Scholar
  31. S.W.H. Cowley, E.J. Bunce, T.S. Stallard, S. Miller, Jupiter’s polar ionospheric flows: theoretical interpretation. Geophys. Res. Lett. 30(5), 1220 (2003). doi: 10.1029/2002GL016030 ADSCrossRefGoogle Scholar
  32. S.W.H. Cowley, E.J. Bunce, J.M. O’Rourke, A simple quantitative model of plasma flows and currents in Saturn’s polar ionosphere. J. Geophys. Res. 109, A05212 (2004a). doi: 10.1029/2003JA010375 ADSCrossRefGoogle Scholar
  33. S.W.H. Cowley, E.J. Bunce, R. Prangé, Saturn’s polar ionospheric flows and their relation to the main auroral oval. Ann. Geophys. 22, 1379–1394 (2004b). doi: 10.5194/angeo-22-1379-2004 ADSCrossRefGoogle Scholar
  34. S.W.H. Cowley, S.V. Badman, E.J. Bunce, J.T. Clarke, J.-C. Gérard, D. Grodent, C.M. Jackman, S.E. Milan, T.K. Yeoman, Reconnection in a rotation-dominated magnetosphere and its relation to Saturn’s auroral dynamics. J. Geophys. Res. 110, A02201 (2005). doi: 10.1029/2004JA010796 ADSGoogle Scholar
  35. S.W.H. Cowley, A.J. Deason, E.J. Bunce, Axi-symmetric models of auroral current systems in Jupiter’s magnetosphere with predictions for the Juno mission. Ann. Geophys. 26, 4051–4074 (2008a). doi: 10.5194/angeo-26-4051-2008 ADSCrossRefGoogle Scholar
  36. S.W.H. Cowley, C.S. Arridge, E.J. Bunce, J.T. Clarke, A.J. Coates, M.K. Dougherty, J.-C. Gérard, D. Grodent, J.D. Nichols, D.L. Talboys, Auroral current systems in Saturn’s magnetosphere: comparison of theoretical models with Cassini and HST observations. Ann. Geophys. 26, 2613–2630 (2008b). doi: 10.5194/angeo-26-2613-2008 ADSCrossRefGoogle Scholar
  37. F.J. Crary et al., Solar wind dynamic pressure and electric field as the main factors controlling Saturn’s aurorae. Nature 433, 720–722 (2005). doi: 10.1038/nature03333 ADSCrossRefGoogle Scholar
  38. P.A. Delamere, F. Bagenal, Modeling variability of plasma conditions in the Io torus. J. Geophys. Res. 108(A7), 1276 (2003). doi: 10.1029/2002JA009706 CrossRefGoogle Scholar
  39. V. Dols, P.A. Delamere, F. Bagenal, W.S. Kurth, W.R. Paterson, Asymmetry of Io’s outer atmosphere: constraints from five Galileo flybys. J. Geophys. Res. 117, E10010 (2012). doi: 10.1029/2012JE004076 ADSCrossRefGoogle Scholar
  40. R.E. Ergun, L. Ray, P.A. Delamere, F. Bagenal, V. Dols, Y.-J. Su, Generation of parallel electric fields in the Jupiter–Io torus wake region. J. Geophys. Res. 114, A05201 (2009). doi: 10.1029/2008JA013968 ADSCrossRefGoogle Scholar
  41. L.W. Esposito et al., The Cassini ultraviolet imaging spectrograph investigation. Space Sci. Rev. 115, 299–361 (2004). doi: 10.1007/s11214-004-1455-8 ADSCrossRefGoogle Scholar
  42. Y.S. Ge, C.T. Russell, K.K. Khurana, Reconnection sites in Jupiter’s magnetotail and relation to jovian auroras. Planet. Space Sci. 58, 1455–1469 (2010). doi: 10.1016/j.pss.2010.06.013 ADSCrossRefGoogle Scholar
  43. J.-C. Gérard, D. Grodent, J. Gustin, A. Saglam, J.T. Clarke, J.T. Trauger, Characteristics of Saturn’s FUV aurora observed with the space telescope imaging spectrograph. J. Geophys. Res. 109, A09207 (2004). doi: 10.1029/2004JA010513 ADSGoogle Scholar
  44. J.-C. Gérard, E.J. Bunce, D. Grodent, S.W.H. Cowley, J.T. Clarke, S.V. Badman, Signature of Saturn’s auroral cusp: simultaneous Hubble space telescope FUV observations and upstream solar wind monitoring. J. Geophys. Res. 110, A11201 (2005). doi: 10.1029/2005JA011094 ADSCrossRefGoogle Scholar
  45. J.-C. Gérard, D. Grodent, A. Radioti, B. Bonfond, J.T. Clarke, Hubble observations of Jupiter’s north–south conjugate ultraviolet aurora. Icarus 226, 1559–1567 (2013). doi: 10.1016/j.icarus.2013.08.017 ADSCrossRefGoogle Scholar
  46. J.-C. Gérard et al., Saturn’s auroral morphology and activity during quiet magnetospheric conditions. J. Geophys. Res. 111, A12210 (2006). doi: 10.1029/2006JA011965 ADSCrossRefGoogle Scholar
  47. D. Grodent, J.H. Waite Jr., J.-C. Gérard, A self-consistent model of the jovian auroral thermal structure. J. Geophys. Res. 106(A7), 12933–12952 (2001). doi: 10.1029/2000JA900129 ADSCrossRefGoogle Scholar
  48. D. Grodent, J.T. Clarke, J. Kim, J.H. Waite Jr., S.W.H. Cowley, Jupiter’s main auroral oval observed with HST-STIS. J. Geophys. Res. 108(A11), 1389 (2003a). doi: 10.1029/2003JA009921 CrossRefGoogle Scholar
  49. D. Grodent, J.T. Clarke, J.H. Waite Jr., S.W.H. Cowley, J.-C. Gerard, J. Kim, Jupiter’s polar auroral emissions. J. Geophys. Res. 108(A10), 1366 (2003b). doi: 10.1029/2003JA010017 CrossRefGoogle Scholar
  50. D. Grodent, J.-C. Gérard, J.T. Clarke, G.R. Gladstone, J.H. Waite Jr., A possible auroral signature of a magnetotail reconnection process on Jupiter. J. Geophys. Res. 109, A05201 (2004). doi: 10.1029/2003JA010341 ADSCrossRefGoogle Scholar
  51. D. Grodent, J.-C. Gérard, S.W.H. Cowley, E.J. Bunce, J.T. Clarke, Variable morphology of Saturn’s southern ultraviolet aurora. J. Geophys. Res. 110, A07215 (2005). doi: 10.1029/2004JA010983 ADSCrossRefGoogle Scholar
  52. D. Grodent, J.-C. Gérard, J. Gustin, B.H. Mauk, J.E.P. Connerney, J.T. Clarke, Europa’s FUV auroral tail on Jupiter. Geophys. Res. Lett. 33, L06201 (2006). doi: 10.1029/2005GL025487 ADSCrossRefGoogle Scholar
  53. D. Grodent, B. Bonfond, J.-C. Gérard, A. Radioti, J. Gustin, J.T. Clarke, J. Nichols, J.E.P. Connerney, Auroral evidence of a localized magnetic anomaly in Jupiter’s northern hemisphere. J. Geophys. Res. 113, A09201 (2008). doi: 10.1029/2008JA013185 ADSGoogle Scholar
  54. D. Grodent, B. Bonfond, A. Radioti, J.-C. Gérard, X. Jia, J.D. Nichols, J.T. Clarke, Auroral footprint of Ganymede. J. Geophys. Res. 114, A07212 (2009). doi: 10.1029/2009JA014289 ADSCrossRefGoogle Scholar
  55. D. Grodent, A. Radioti, B. Bonfond, J.-C. Gérard, On the origin of Saturn’s outer auroral emission. J. Geophys. Res. 115, A08219 (2010). doi: 10.1029/2009JA014901 ADSCrossRefGoogle Scholar
  56. D. Grodent, J. Gustin, J.-C. Gérard, A. Radioti, B. Bonfond, W.R. Pryor, Small-scale structures in Saturn’s ultraviolet aurora. J. Geophys. Res. 116, A09225 (2011). doi: 10.1029/2011JA016818 ADSCrossRefGoogle Scholar
  57. D.A. Gurnett, W.S. Kurth, F.L. Scarf, R.L. Poynter, First plasma wave observations at Uranus. Science 233(4759), 106–109 (1986). doi: 10.1126/science.233.4759.106 ADSCrossRefGoogle Scholar
  58. J. Gustin, S.W.H. Cowley, J.-C. Gérard, G.R. Gladstone, D. Grodent, J.T. Clarke, Characteristics of jovian morning bright FUV aurora from Hubble space telescope/space telescope imaging spectrograph imaging and spectral observations. J. Geophys. Res. 111, A09220 (2006). doi: 10.1029/2006JA011730 ADSCrossRefGoogle Scholar
  59. J. Gustin, J.-C. Gérard, W. Pryor, P.D. Feldman, D. Grodent, G. Holsclaw, Characteristics of Saturn’s polar atmosphere and auroral electrons derived from HST/STIS, FUSE and Cassini/UVIS spectra. Icarus 200, 176–187 (2009). doi: 10.1016/j.icarus.2008.11.013 ADSCrossRefGoogle Scholar
  60. J. Gustin, B. Bonfond, D. Grodent, J.-C. Gérard, Conversion from HST ACS and STIS auroral counts into brightness, precipitated power, and radiated power for \(\mathrm{H}_{2}\) giant planets. J. Geophys. Res. 117, A07316 (2012). doi: 10.1029/2012JA017607 ADSCrossRefGoogle Scholar
  61. J. Gustin, J.-C. Gérard, D. Grodent, G.R. Gladstone, J.T. Clarke, W.R. Pryor, V. Dols, B. Bonfond, A. Radioti, L. Lamy, J.M. Ajello, Effects of methane on giant planet’s UV emissions and implications for the auroral characteristics. J. Mol. Spectrosc. 291, 108–117 (2013). doi: 10.1016/j.jms.2013.03.010 ADSCrossRefGoogle Scholar
  62. S.L.G. Hess, P. Delamere, V. Dols, B. Bonfond, D. Swift, Power transmission and particle acceleration along the Io flux tube. J. Geophys. Res. 115, A06205 (2010a). doi: 10.1029/2009JA014928 ADSGoogle Scholar
  63. S.L.G. Hess, A. Pétin, P. Zarka, B. Bonfond, B. Cecconi, Lead angles and emitting electron energies of Io-controlled decameter radio arcs. Planet. Space Sci. 58(10), 1188–1198 (2010b). doi: 10.1016/j.pss.2010.04.011 ADSCrossRefGoogle Scholar
  64. S.L.G. Hess, B. Bonfond, P.A. Delamere, How could the Io footprint disappear? Planet. Space Sc. (2013, in press). doi: 10.1016/j.pss.2013.08.014 Google Scholar
  65. F. Herbert, B.R. Sandel, The uranian aurora and its relationship to the magnetosphere. J. Geophys. Res. 99(A3), 4143–4160 (1994). doi: 10.1029/93JA02673 ADSCrossRefGoogle Scholar
  66. F. Herbert, Aurora and magnetic field of Uranus. J. Geophys. Res. 114, A11206 (2009). doi: 10.1029/2009JA014394 ADSCrossRefGoogle Scholar
  67. T.W. Hill, A.J. Dessler, Convection in Neptune’s magnetosphere. Geophys. Res. Lett. 17, 1677–1680 (1990). doi: 10.1029/GL017i010p01677 ADSCrossRefGoogle Scholar
  68. T.W. Hill, The jovian auroral oval. J. Geophys. Res. 106, 8101–8107 (2001) ADSCrossRefGoogle Scholar
  69. T.W. Hill, V.M. Vasyliūnas, Jovian auroral signature of Io’s corotational wake. J. Geophys. Res. 107(A12), 1464 (2002). doi: 10.1029/2002JA009514 CrossRefGoogle Scholar
  70. C.M. Jackman, N. Achilleo, S.W.H. Cowley, E.J. Bunce, A. Radioti, D. Grodent, S.V. Badman, M.K. Dougherty, W. Pryor, Auroral counterpart of magnetic field dipolarizations in Saturn’s tail. Planet. Space Sci. 82–83, 34–42 (2013). 2013. doi: 10.1016/j.pss.2013.03.010 CrossRefGoogle Scholar
  71. S. Jacobsen, F.M. Neubauer, J. Saur, N. Schilling, Io’s nonlinear MHD-wave field in the heterogeneous jovian magnetosphere. Geophys. Res. Lett. 34, L10202 (2007). doi: 10.1029/2006GL029187 ADSCrossRefGoogle Scholar
  72. X. Jia, R.J. Walker, M.G. Kivelson, K.K. Khurana, J.A. Linker, Dynamics of Ganymede’s magnetopause: intermittent reconnection under steady external conditions. J. Geophys. Res. 115, A12202 (2010). doi: 10.1029/2010JA015771 ADSGoogle Scholar
  73. S. Kasahara, E.A. Kronberg, T. Kimura, C. Tao, S.V. Badman, A. Masters, A. Retinò, N. Krupp, M. Fujimoto, Asymmetric distribution of reconnection jet fronts in the jovian nightside magnetosphere. J. Geophys. Res. 118, 375–384 (2013). doi: 10.1029/2012JA018130 CrossRefGoogle Scholar
  74. K.K. Khurana, Influence of solar wind on Jupiter’s magnetosphere deduced from currents in the equatorial plane. J. Geophys. Res. 106(A11), 25999–26016 (2001). doi: 10.1029/2000JA000352 ADSCrossRefGoogle Scholar
  75. M.G. Kivelson, K.K. Khurana, D.J. Stevenson, L. Bennett, S. Joy, C.T. Russell, R.J. Walker, C. Zimmer, C. Polanskey, Europa and Callisto: induced or intrinsic fields in a periodically varying plasma environment. J. Geophys. Res. 104(A3), 4609–4625 (1999). doi: 10.1029/1998JA900095 ADSCrossRefGoogle Scholar
  76. M.G. Kivelson, D.J. Southwood, Dynamical consequences of two modes of centrifugal instability in Jupiter’s outer magnetosphere. J. Geophys. Res. 110, A12209 (2005). doi: 10.1029/2005JA011176 ADSCrossRefGoogle Scholar
  77. N. Krupp, A. Lagg, S. Livi, B. Wilken, J. Woch, E.C. Roelof, D.J. Williams, Global flows of energetic ions in Jupiter’s equatorial plane: first-order approximation. J. Geophys. Res. 106(A11), 26017–26032 (2001). doi: 10.1029/2000JA900138 ADSCrossRefGoogle Scholar
  78. W.S. Kurth, D.A. Gurnett, Plasma waves in planetary magnetospheres. J. Geophys. Res. 96(S01), 18977–18991 (1991). doi: 10.1029/91JA01819 ADSCrossRefGoogle Scholar
  79. W.S. Kurth, A. Lecacheux, T.F. Averkamp, J.B. Groene, D.A. Gurnett, A saturnian longitude system based on a variable kilometric radiation period. Geophys. Res. Lett. 34, L02201 (2007). doi: 10.1029/2006GL028336 ADSCrossRefGoogle Scholar
  80. W.S. Kurth, T.F. Averkamp, D.A. Gurnett, J.B. Groene, A. Lecacheux, An update to a saturnian longitude system based on kilometric radio emissions. J. Geophys. Res. 113, A05222 (2008). doi: 10.1029/2007JA012861 ADSCrossRefGoogle Scholar
  81. W.S. Kurth, E.J. Bunce, J.T. Clarke, F.J. Crary, D.C. Grodent, A.P. Ingersoll, U.A. Dyudina, L. Lamy, D.G. Mitchell, A.M. Persoon, W.R. Pryor, J. Saur, T. Stallard, Auroral processes, in Saturn from Cassini-Huygens, vol. 12, ed. by M. Dougherty et al. (Springer, Dordrecht, 2009), pp. 333–374 CrossRefGoogle Scholar
  82. L. Lamy, B. Cecconi, R. Prangé, P. Zarka, J.D. Nichols, J.T. Clarke, An auroral oval at the footprint of Saturn’s kilometric radio sources, colocated with the UV aurorae. J. Geophys. Res. 114, A10212 (2009). doi: 10.1029/2009JA014401 ADSGoogle Scholar
  83. L. Lamy et al., Earth-based detection of Uranus’ aurorae. Geophys. Res. Lett. 39, L07105 (2012). doi: 10.1029/2012GL051312 ADSCrossRefGoogle Scholar
  84. G.R. Lewis, N. André, C.S. Arridge, A.J. Coates, L.K. Gilbert, D.R. Linder, A.M. Rymer, Derivation of density and temperature from the Cassini-Huygens CAPS electron spectrometer. Planet. Space Sci. 56, 901–912 (2008). doi: 10.1016/j.pss.2007.12.017 ADSCrossRefGoogle Scholar
  85. B.H. Mauk, S.M. Krimigis, M.H. Acuña, Neptune’s inner magnetosphere and aurora: energetic particle constraints. J. Geophys. Res. 99(A8), 14781–14788 (1994). doi: 10.1029/94JA00735 ADSCrossRefGoogle Scholar
  86. B.H. Mauk, J.T. Clarke, D. Grodent, J.H. Waite Jr., C.P. Paranicas, D.J. Williams, Transient aurora on Jupiter from injections of magnetospheric electrons. Nature 415, 1003–1005 (2002) ADSCrossRefGoogle Scholar
  87. H. Melin, T. Stallard, S. Miller, L.M. Trafton, T. Encrenaz, T.R. Geballe, Seasonal variability in the ionosphere of Uranus. Astrophys. J. 729, 134 (2011). doi: 10.1088/0004-637X/729/2/134 ADSCrossRefGoogle Scholar
  88. H. Melin, T. Stallard, S. Miller, T.R. Geballe, L.R. Trafton, J. O’Donoghue, Post-equinoctial observations of the ionosphere of Uranus. Icarus 223(2), 741–748 (2013). doi: 10.1016/j.icarus.2013.01.012 ADSCrossRefGoogle Scholar
  89. J.D. Menietti, D.A. Gurnett, I. Christopher, Control of jovian radio emission by Callisto. Geophys. Res. Lett. 28, 3047–3050 (2001). doi: 10.1029/2001GL012965 ADSCrossRefGoogle Scholar
  90. C.J. Meredith, S.W.H. Cowley, K.C. Hansen, J.D. Nichols, T.K. Yeoman, Simultaneous conjugate observations of small-scale structures in Saturn’s dayside ultraviolet auroras: implications for physical origins. J. Geophys. Res. 118, 2244–2266 (2013). doi: 10.1002/jgra.50270 CrossRefGoogle Scholar
  91. S.E. Milan, M. Lester, S.W.H. Cowley, M. Brittnacher, Dayside convection and auroral morphology during an interval of northward interplanetary magnetic field. Ann. Geophys. 18, 436–444 (2000) ADSCrossRefGoogle Scholar
  92. D.G. Mitchell et al., Recurrent energization of plasma in the midnight-to-dawn quadrant of Saturn’s magnetosphere, and its relationship to auroral UV and radio emissions. Planet. Space Sci. 57, 1732–1742 (2009). doi: 10.1016/j.pss.2009.04.002 ADSCrossRefGoogle Scholar
  93. J.D. Nichols, S.W.H. Cowley, Magnetosphere-ionosphere coupling currents in Jupiter’s middle magnetosphere: effect of precipitation-induced enhancement of the ionospheric Pedersen conductivity. Ann. Geophys. 22, 1799–1827 (2004). doi: 10.5194/angeo-22-1799-2004 ADSCrossRefGoogle Scholar
  94. J.D. Nichols, J.T. Clarke, S.W.H. Cowley, J. Duval, A.J. Farmer, J.-C. Gérard, D. Grodent, S. Wannawichian, Oscillation of Saturn’s southern auroral oval. J. Geophys. Res. 113, A11205 (2008). doi: 10.1029/2008JA013444 ADSCrossRefGoogle Scholar
  95. J.D. Nichols, J.T. Clarke, J.C. Gérard, D. Grodent, Observations of jovian polar auroral filaments. Geophys. Res. Lett. 36, L08101 (2009a). doi: 10.1029/2009GL037578 ADSGoogle Scholar
  96. J.D. Nichols, S.V. Badman, E.J. Bunce, J.T. Clarke, S.W.H. Cowley, F.J. Crary, M.K. Dougherty, J.-C. Gérard, D. Grodent, K.C. Hansen, W.S. Kurth, D.G. Mitchell, W.R. Pryor, T.S. Stallard, D.L. Talboys, S. Wannawichian, Saturn’s equinoctial auroras. Geophys. Res. Lett. 36, L24102 (2009b). doi: 10.1029/2009GL041491 ADSCrossRefGoogle Scholar
  97. J.D. Nichols, S.W.H. Cowley, L. Lamy, Dawn-dusk oscillation of Saturn’s conjugate auroral ovals. Geophys. Res. Lett. 37, L24102 (2010a). doi: 10.1029/2010GL045818 ADSGoogle Scholar
  98. J.D. Nichols, B. Cecconi, J.T. Clarke, S.W.H. Cowley, J.-C. Gérard, A. Grocott, D. Grodent, L. Lamy, P. Zarka, Variation of Saturn’s UV aurora with SKR phase. Geophys. Res. Lett. 37, L15102 (2010b). doi: 10.1029/2010GL044057 ADSGoogle Scholar
  99. T. Ogino, R.J. Walker, M.G. Kivelson, A global magnetohydrodynamic simulation of the jovian magnetosphere. J. Geophys. Res. 103(A1), 225–235 (1998). doi: 10.1029/97JA02247 ADSCrossRefGoogle Scholar
  100. L. Pallier, R. Prangé, More about the structure of the high latitude jovian aurorae. Planet. Space Sci. 49, 1159–1173 (2001) ADSCrossRefGoogle Scholar
  101. C. Paranicas, A.F. Cheng, Drift shells and aurora computed using the O8 magnetic field model for Neptune. J. Geophys. Res. 99(A10), 19433–19440 (1994). doi: 10.1029/94JA01573 ADSCrossRefGoogle Scholar
  102. W.R. Pryor et al., The auroral footprint of Enceladus on Saturn. Nature 472, 331–333 (2011). doi: 10.1038/nature09928 ADSCrossRefGoogle Scholar
  103. A. Radioti, J.-C. Gérard, D. Grodent, B. Bonfond, N. Krupp, J. Woch, Discontinuity in Jupiter’s main auroral oval. J. Geophys. Res. 113, A01215 (2008). doi: 10.1029/2007JA012610 ADSCrossRefGoogle Scholar
  104. A. Radioti, A.T. Tomás, D. Grodent, J.-C. Gérard, J. Gustin, B. Bonfond, N. Krupp, J. Woch, J.D. Menietti, Equatorward diffuse auroral emissions at Jupiter: simultaneous HST and Galileo observations. Geophys. Res. Lett. 36, L07101 (2009a). doi: 10.1029/2009GL037857 ADSGoogle Scholar
  105. A. Radioti, D. Grodent, J.-C. Gérard, E. Roussos, C. Paranicas, B. Bonfond, D.G. Mitchell, N. Krupp, S. Krimigis, J.T. Clarke, Transient auroral features at Saturn: signatures of energetic particle injections in the magnetosphere. J. Geophys. Res. 114, A03210 (2009b). doi: 10.1029/2008JA013632 ADSCrossRefGoogle Scholar
  106. A. Radioti, D. Grodent, J.-C. Gérard, M.F. Vogt, M. Lystrup, B. Bonfond, Nightside reconnection at Jupiter: auroral and magnetic field observations from 26 July 1998. J. Geophys. Res. 116, A03221 (2011a). doi: 10.1029/2010JA016200 ADSCrossRefGoogle Scholar
  107. A. Radioti, D. Grodent, J.-C. Gérard, S.E. Milan, B. Bonfond, J. Gustin, W. Pryor, Bifurcations of the main auroral ring at Saturn: ionospheric signatures of consecutive reconnection events at the magnetopause. J. Geophys. Res. 116, A11209 (2011b). doi: 10.1029/2011JA016661 ADSCrossRefGoogle Scholar
  108. A. Radioti, M. Lystrup, B. Bonfond, D. Grodent, J.-C. Gérard, Jupiter’s aurora in ultraviolet and infrared: simultaneous observations with the Hubble space telescope and the NASA infrared telescope facility. J. Geophys. Res. 118, 2286–2295 (2013a). doi: 10.1002/jgra.50245 CrossRefGoogle Scholar
  109. A. Radioti, E. Roussos, D. Grodent, J.-C. Gérard, N. Krupp, D.G. Mitchell, J. Gustin, B. Bonfond, W. Pryor, Signatures of magnetospheric injections in Saturn’s aurora. J. Geophys. Res. 118, 1922–1933 (2013b). doi: 10.1002/jgra.50161 CrossRefGoogle Scholar
  110. A. Radioti, D. Grodent, J.-C. Gérard, B. Bonfond, J. Gustin, W. Pryor, J.M. Jasinski, C.S. Arridge, Auroral signatures of multiple magnetopause reconnection at Saturn. Geophys. Res. Lett. 40, 4498–4502 (2013c). doi: 10.1002/grl.50889 ADSCrossRefGoogle Scholar
  111. B.R. Sandel, F. Herbert, A.J. Dessler, T.W. Hill, Aurora and airglow on the night side of Neptune. Geophys. Res. Lett. 17, 1693 (1990). doi: 10.1029/GL017i010p01693 ADSCrossRefGoogle Scholar
  112. J. Saur, D.F. Strobel, F.M. Neubauer, M.E. Summers, The ion mass loading rate at Io. Icarus 163, 456–468 (2003). doi: 10.1016/S0019-1035(03)00085-X ADSCrossRefGoogle Scholar
  113. P. Schippers et al., Multi-instrument analysis of electron populations in Saturn’s magnetosphere. J. Geophys. Res. 113, A07208 (2008). doi: 10.1029/2008JA013098 ADSCrossRefGoogle Scholar
  114. P. Schippers, N. André, D.A. Gurnett, G.R. Lewis, A.M. Persoon, A.J. Coates, Identification of electron field-aligned current systems in Saturn’s magnetosphere. J. Geophys. Res. 117, A05204 (2012). doi: 10.1029/2011JA017352 ADSCrossRefGoogle Scholar
  115. E.C. Sittler Jr., K.W. Ogilvie, R. Selesnick, Survey of electrons in the uranian magnetosphere: Voyager 2 observations. J. Geophys. Res. 92, 15263–15281 (1987). doi: 10.1029/JA092iA13p15263 ADSCrossRefGoogle Scholar
  116. D.J. Southwood, M.G. Kivelson, A new perspective concerning the influence of the solar wind on the jovian magnetosphere. J. Geophys. Res. 106(A4), 6123–6130 (2001). doi: 10.1029/2000JA000236 ADSCrossRefGoogle Scholar
  117. D.J. Southwood, M.G. Kivelson, Saturnian magnetospheric dynamics: elucidation of a camshaft model. J. Geophys. Res. 112, A12222 (2007). doi: 10.1029/2007JA012254 ADSCrossRefGoogle Scholar
  118. T.S. Stallard, S. Miller, S.W.H. Cowley, E.J. Bunce, Jupiter’s polar ionospheric flows: measured intensity and velocity variations poleward of the main auroral oval. Geophys. Res. Lett. 30(5), 1221 (2003). doi: 10.1029/2002GL016031 ADSCrossRefGoogle Scholar
  119. S. Stanley, J. Bloxham, Numerical dynamo models of Uranus and Neptune’s magnetic fields. Icarus 184, 556–572 (2006). doi: 10.1016/j.icarus.2006.05.005 ADSCrossRefGoogle Scholar
  120. D.L. Talboys, E.J. Bunce, S.W.H. Cowley, C.S. Arridge, A.J. Coates, M.K. Dougherty, Statistical characteristics of field-aligned currents in Saturn’s nightside magnetosphere. J. Geophys. Res. 116, A04213 (2011). doi: 10.1029/2010JA016102 ADSCrossRefGoogle Scholar
  121. A.T. Tomás, J. Woch, N. Krupp, A. Lagg, K.-H. Glassmeier, W.S. Kurth, Energetic electrons in the inner part of the jovian magnetosphere and their relation to auroral emissions. J. Geophys. Res. 109, A06203 (2004). doi: 10.1029/2004JA010405 ADSCrossRefGoogle Scholar
  122. A.R. Vasavada, A.H. Bouchez, A.P. Ingersoll, B. Little, C.D. Anger (the Galileo SSI Team), Jupiter’s visible aurora and Io footprint. J. Geophys. Res. 104, 27133–27142 (1999) ADSCrossRefGoogle Scholar
  123. V.M. Vasyliūnas, Plasma distribution and flow, in Physics of the Jovian Magnetosphere, ed. by A.J. Dessler (Cambridge Univ. Press, New York, 1983), pp. 395–453. doi: 10.1017/CBO9780511564574.013 CrossRefGoogle Scholar
  124. M.F. Vogt, M.G. Kivelson, K.K. Khurana, R.J. Walker, B. Bonfond, D. Grodent, A. Radioti, Improved mapping of Jupiter’s auroral features to magnetospheric sources. J. Geophys. Res. 116, A03220 (2011). doi: 10.1029/2010JA016148 ADSCrossRefGoogle Scholar
  125. M.F. Vogt, C.M. Jackman, J.A. Slavin, E.J. Bunce, S.W.H. Cowley, M.G. Kivelson, K.K. Khurana, Structure and statistical properties of plasmoids in Jupiter’s magnetotail. J. Geophys. Res. 119, 821–843 (2014). doi: 10.1002/2013JA019393 CrossRefGoogle Scholar
  126. H. Waite et al., An auroral flare at Jupiter. Nature 410(6830), 787–789 (2001) ADSCrossRefGoogle Scholar
  127. F. Xiao, R.M. Thorne, D.A. Gurnett, D.J. Williams, Whistler-mode excitation and electron scattering during an interchange event near Io. Geophys. Res. Lett. 30(14), 1749 (2003). doi: 10.1029/2003GL017123 ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.Université de LiègeLiègeBelgium

Personalised recommendations