Transport in Saturn's Inner Magnetosphere: Using Particle and Wave Data to Study Rayleigh-Taylor like Interchange Instability Injection Events

We investigate the plasma mass transport process known as interchange instability using data analysis and modeling. Interchange instabilities are spatially small but ubiquitous flows of hot ambient plasma into the cold Enceladus torus, resembling Rayleigh-Taylor instabilities within Saturn's inner magnetosphere. Although evidenced with Cassini spacecraft observations, their role in plasma transport and causal relationship with large-scale current-sheet collapse injection processes is not well understood. 

We offer a unifying review of interchange injections seen in past statistical surveys [Azari et al., 2018; Chen & Hill, 2008; Kennelly et al., 2013; Lai et al., 2016] by explaining measurements from the Radio and Plasma Science (RPWS) instrument, and comparing wave-types and properties against characteristics seen co-occurring in the particle sensors (ion and electron in MIMI and CAPS), and magnetometer (MAG). Additionally, we investigate the conditions within the inner magnetosphere of Saturn using the Hot Electron and Ion Drift Integrator (HEIDI), a drift kinetic model that solves the gyro- and bounce-averaged Boltzmann equation for the energetic plasma population [Liemohn et al., 2001, 2006; Ilie et al., 2012, 2013; Liu and Ilie, 2021]. Originally designed for Earth, we will present steps taken towards adapting this model for Saturn and reproducing interchange instability injections as a source/loss term for the environment.