[P-EM10] Dynamics of Magnetosphere and Ionosphere

[PEM10-13] Variation of electron distribution in Jupiter's magnetosphere during Io volcanic activity change using data from the HISAKI satellite and Juno spacecraft

*Saniya Sanada¹, Kazuo Yoshioka¹ (1.University of Tokyo)

Keywords:Jupiter, Magnetosphere, Io, Hisaki, Juno

Jupiter has the strongest intrinsic magnetic field in the solar system and forms a huge magnetosphere due to its high-speed rotation. The satellite Io, which orbits Jupiter's inner magnetosphere (<10RJ), has intense volcanic activity on its surface, and the erupted gas escapes from Io's gravitation sphere and is ejected into space. The ionized plasma from this gas is trapped by Jupiter's magnetic field and forms a torus-shaped plasma belt (Io plasma torus) due to the balance between Jupiter's rotational angular momentum and centrifugal force. Observations by the HISAKI satellite have revealed that the electron impact emission of the plasma in the Io plasma torus increases with the increase in Io eruptive activity. Furthermore, it was suggested that the plasma with increased energy and quantity is transported toward the outer magnetosphere due to mass loading. However, the field of view of the HISAKI satellite is limited to around 8RJ, which includes Jupiter and the Io plasma torus, and it cannot observe plasma farther away from the torus. Juno observes the entire Jupiter magnetosphere, including the outer magnetosphere, and can observe beyond the field of view of Hisaki. Juno measures electron energy with in-situ observations, but the consistency with the electron information obtained from Hisaki, which is a distant observation, has not been confirmed. Therefore, in this study, I used particle observation data from Juno in addition to the Hisaki satellite to determine the time evolution and spatial distribution of electron parameters in the magnetosphere after the Io eruption. First, the emission line emissions of major ions in the ion torus, such as sulfur and oxygen, were determined for each wavelength associated with each energy transition by the HISAKI satellite, and electron temperature and density parameters were obtained by comparing them with a database of electron impact cross sections (CHIANTI 10.0.2). The parameters were compared with the electron parameters obtained from the Juno spacecraft observations to confirm the consistency of the observed data in the inner magnetosphere. The radial plasma transport in the inner magnetosphere after the Io eruption was then investigated using the observation data in the inner magnetosphere by the HISAKI satellite and in the outer magnetospheric region by the Juno spacecraft. In this presentation, I will summarize the results of electron temperature and density values calculated from the ion spectral data obtained from the HISAKI observations and the comparison of electron parameters obtained by Juno and discuss the plasma transport state from the temporal and spatial variation of electron energy distribution in Jupiter's magnetosphere.