Simulations of Io Plasma Torus Around Jupiter: Predictions for Lenghu Observatory

Abstract

Characterizing the temporal evolution of the three-dimensional structure of the Io plasma torus is essential to understand the dynamics of the Jovian magnetosphere. Optical imaging is a powerful tool to uncover the global torus structure. Currently, two ground-based optical telescopes with diameters of 0.8 and 1.8 m, respectively, are under construction at the Lenghu Observatory for Planetary Science on the Tibetan Plateau of China, to systematically observe the Io plasma torus at wavelengths between 392 and 1,100 nm. These telescopes will begin to operate in the end of 2023. In order to support the inversion and scientific interpretation of the Io plasma torus images, we perform systematic simulations of the Io plasma torus in this work. First, a three-dimensional model of electron and ion densities and electron temperature is constructed first. Then, the emissions of O+ 372.7 nm, O+ 372.9 nm, S+ 406.9 nm, S+ 671.8 nm, S+ 673.1 nm, and S++ 953.2 nm are simulated from the perspective of observing from the Earth. The simulated emission intensities and distributions are consistent with previous observations. This work provides a state-of-the-art convenient tool for ground-based telescope observation of the Io plasma torus at a specific site and time and also benefits future inversion of images to obtain physical parameters of Io plasma torus.