Configuration and dynamics of the Jovian magnetosphere

[1] A massive rotating equatorial plasma sheet dominates Jupiter's magnetosphere and the solar wind and the interplanetary magnetic field (IMF) are not thought to be as important as at Earth. However, in a recent simulation study we found that for a purely northward IMF the Jovian magnetosphere reached an unstable state in which a nearly periodic series of magnetic X and O lines were launched tailward. In this study we have carried out three-dimensional global magnetohydrodynamic simulations to investigate the causes of this dynamic behavior. First, we examined the effects of dynamic pressure on the magnetospheric configuration in the absence of an IMF. We examined a series of northward IMF simulations in which we varied both the IMF magnitude and dynamic pressure. If the outer edge of the rotating plasma sheet is far from the X-line (for large pressure and small IMF), the reconnected flow reaches the dawn magnetopause and exits down the tail. If the neutral line forms closer to the rotation boundary (small pressure and IMF), then the reconnected flux tubes can convect all of the way around Jupiter. When they reach the nightside, they become stretched tailward and can reconnect again. This leads to the periodic behavior. If the neutral line forms very close to the rotation boundary (large pressure and IMF), the Jupiterward flow compresses the rotating plasma sheet. In this case the flow goes around Jupiter but the flux tubes return along the dusk magnetopause and do not participate in reconnection a second time.

[1]  K. Kusano,et al.  A global MHD simulation of the Jovian magnetosphere interacting with/without the interplanetary magnetic field , 2001 .

[2]  Emma J. Bunce,et al.  Jupiter's polar ionospheric flows: Theoretical interpretation , 2003 .

[3]  Norbert Krupp,et al.  Particle bursts in the Jovian magnetosphere: Evidence for a near‐Jupiter neutral line , 2002 .

[4]  K. Kusano,et al.  MHD simulation of a rapidly rotating magnetosphere interacting with the external plasma flow , 1997 .

[5]  E. Smith,et al.  Compression of Jupiter's magnetosphere by the solar wind , 1978 .

[6]  R. McNutt,et al.  Plasma Observations Near Jupiter: Initial Results from Voyager 1 , 1979, Science.

[7]  David J. Southwood,et al.  A new perspective concerning the influence of the solar wind on the Jovian magnetosphere , 2001 .

[8]  T. Hill,et al.  The Jovian auroral oval , 2001 .

[9]  J. Belcher.  Physics of the Jovian magnetosphere. 3. The low-energy plasma in the Jovian magnetosphere. , 1983 .

[10]  V. Vasyliūnas,et al.  Plasma distribution and flow , 1983 .

[11]  M. Kivelson,et al.  The Locations and Shapes of Jupiter’s Bow Shock and Magnetopause , 2005 .

[12]  R. S. Wolff,et al.  Plasma Observations Near Uranus: Initial Results from Voyager 2 , 1979, Science.

[13]  Emma J. Bunce,et al.  Origin of the main auroral oval in Jupiter's coupled magnetosphere–ionosphere system , 2001 .

[14]  H. Bridge,et al.  The low energy plasma in the Jovian magnetosphere , 1980 .

[15]  M. Kivelson,et al.  A global magnetohydrodynamic simulation of the Jovian magnetosphere , 1998 .

[16]  R. Walker,et al.  A simulation study of currents in the Jovian magnetosphere , 2003 .

[17]  R. Walker,et al.  Dynamics of the Jovian magnetosphere for northward interplanetary magnetic field (IMF) , 2005 .

[18]  T. Hill,et al.  Physics of the Jovian magnetosphere. 10. Magnetospheric models. , 1983 .

[19]  Donald A. Gurnett,et al.  A study of the Jovian “energetic magnetospheric events” observed by Galileo: role in the radial plasma transport , 2000 .

[20]  E. Smith,et al.  Jupiter's magnetic field and magnetosphere , 1976 .

[21]  Tetsuya Sato,et al.  Global simulation of the solar wind-magnetosphere interaction: The importance of its numerical validity , 1990 .

[22]  D. Williams,et al.  Global flows of energetic ions in Jupiter's equatorial plane: First‐order approximation , 2001 .

[23]  Krishan K. Khurana,et al.  Mass release at Jupiter: Substorm-like processes in the Jovian magnetotail , 2005 .

[24]  Christopher T. Russell,et al.  Probabilistic models of the Jovian magnetopause and bow shock locations , 2002 .

[25]  M. Ashour‐Abdalla,et al.  A global magnetohydrodynamic simulation of the magnetosheath and magnetosphere when the interplaneta , 1992 .

[26]  J. Phillips,et al.  Ulysses plasma observations in the Jovian magnetosheath , 1993 .

[27]  Emma J. Bunce,et al.  Jupiter's polar ionospheric flows: Measured intensity and velocity variations poleward of the main auroral oval , 2003 .

[28]  Donald A. Gurnett,et al.  A study of the large‐scale dynamics of the Jovian magnetosphere using the Galileo Plasma Wave Experiment , 1998 .

[29]  Travis W. Hill,et al.  Inertial limit on corotation , 1979 .

[30]  M. Kivelson,et al.  Magnetohydrodynamic simulations of the effects of the solar wind on the Jovian magnetosphere , 2001 .