A comparison of the interaction of the solar wind with the Jovian and Kronian magnetospheres

We have developed a method of exploring properties on either side of Jupiter's magnetopause that allows us to evaluate the transfer of energy and magnetic flux across the boundary. We compare the plasma flows, densities, and magnetic fields on either side of the magnetopause boundary to determine regions along the magnetopause that are susceptible to the Kelvin-Helmholtz instability (KHI). We also consider the possibility of large-scale reconnection based on the magnetic field shear angle and magnitude. In this work we extend this method to the Kronian magnetosphere. The magnetopause boundary is treated as a tangential discontinuity, the shape of which is given by a nonaxisymmetric paraboloid. The degree of asymmetry at each planet is based on theoretical modeling (Engle and Beard, JGR 85, 1980; Stahara et al, JGR 94, 1989) and data (Slavin et al, JGR 90, 1985). The magnetosheath magnetic field and plasma properties for both magnetospheres are provided by Erkaev et al (JGR 101, 1996) and Farrugia et al (Planet. Space. Sci. 46, 1998). Empirical models of the magnetosphere conditions are based on various spacecraft measurements. We find that, at Jupiter, due to the large shear flows and rotation of the magnetic field in the magnetosheath, both flanks exhibit regions susceptible to the instability. We find also that the magnetic fields approach an antiparallel configuration in some regions, though the shear magnitude is generally weaker than the reconnection onset criterion considered at Earth (e.g. by Cooling et al, JGR 106, 2001).