Dynamic Jovian Magnetosphere Responses to Enhanced Solar Wind Ram Pressure

Jupiter has the largest magnetosphere and the most intense auroral emissions in the solar system. However, the mechanisms of Jovian auroral emissions are not fully understood. The main emission (ME) of the Jovian aurora is thought to be related to the current system associated with the breakdown of plasma corotation in the middle magnetosphere. According to this mainstream corotation breakdown model, the intensity of the Jovian ME is expected to decrease when the solar wind (SW) ram pressure increases, which is not fully consistent with auroral observations. This inconsistency drives us to explore the auroral activities response to enhanced solar wind ram pressure through numerical simulations. In addition to the field-aligned current (FAC), Alfvénic power (AP) play an important role in regulating planetary auroral emissions. Therefore, we use three-dimensional global simulations to investigate how these proxies of auroral emission respond to enhanced SW ram pressure. We found that during SW compression, both FAC and AP experience up-down-up trends, which is not revealed by any previous model, while could potentially explains many auroral observations. The results can significantly improve our understanding on the Jovian magnetospheric response modes to enhanced solar wind ram pressure, and the Jovian auroral mechanisms.