Studying Ganymede's Magnetosphere Configuration During Different Galileo Flybys Using the Gkeyll Ten-Moment Multifluid Model with Coupled Resistive Mantle Interior

Abstract:

We perform comparative numerical case studies of the Ganymede's magnetosphere during different Galileo flybys, using the Gkeyll ten-moment multifluid model. Recently, we have improved the model by including a resistive mantle and a conducting core inside the body, which is often considered to complicate the moon's responses to the Jovian forcing. In addition, we have improved the agreement between brightness modeling and observation by coupling the Gkeyll ten-moment multifluid model to an existing semi-empirical aurora brightness model. This brightness model requires electron parameters as input, which will be provided directly by the multifluid model, instead of being derived from ion or MHD quantities. Using hypothetical upstream Jovian plasma and electromagnetic field conditions, we will study, during different Galileo flybys, the detailed magnetosphere configuration like plasma distribution, magnetic field structure, and surface energetic plasma fluxes. The study also provides insights into the short- and long-period variabilities in Ganymede's observed brightness patterns.