Modeling Magnetic Field Perturbations Near Enceladus

Pontius and Hill [2006] presented a model for plasma deflection near Enceladus due to plasma mass loading and subsequent shielding of the corotation electric field. The model parameters are chosen to obtain reasonable agreement with plasma velocities obtained by the CAPS instrument, without considering magnetic perturbations. Indeed, the model employs a constant magnetic field, in agreement with Cassini MAG findings that the measured magnetic field perturbations are much smaller than the background field. We calculate the magnetic perturbations produced by the electric currents in the PH06 model and compare them with MAG data along Cassini's path to obtain an additional assessment of the model. Preliminary results show good qualitative agreement, particularly when the mass injection is restricted to the southern hemisphere. The model also predicts the distribution of field-aligned currents into Saturn's ionosphere, which we use to calculate the intensity of auroral emissions. Our results suggest a maximum emission of a few hundred Rayleighs.