Probabilistic models of the Jovian magnetopause and bow shock locations

New three-dimensional models of the Jovian magnetopause and bow shock were derived by combining spacecraft observations with boundary characteristics inferred from a magnetohydrodynamic (MHD) simulation. The MHD simulation provides polynomial forms parameterized by solar wind dynamic pressure. Observations from Pioneer 10 and 11, Voyager 1 and 2, Ulysses, and Galileo were used to establish the probability that regions surrounding Jupiter fall inside or outside these boundary surfaces. The magnetopause location was found to have a bimodal probability distribution with the two most probable standoff distances at 63 R-J (sigma=4 R-J) and 92 R-J (sigma=6 R-J). The bow shock location distribution appears bimodal, but a single distribution function description cannot be ruled out at the 95% confidence level. The mean bow shock standoff distance is 84 R-J (sigma=16 R-J). Analysis of solar wind measurements near 5.2 AU (interplanetary magnetic field, dynamic pressure, and Alfven Mach number) suggests that the bimodal distribution of boundary positions results at least in part from the bimodal distribution of solar wind parameters in the vicinity of Jupiter. The probability density distributions of these parameters within and between regions of disturbed solar wind, caused by corotating interaction regions and coronal mass ejections, are statistically distinct. Smaller variations were also observed in these parameters over the solar cycle.