An assessment and test of Enceladus as an important source of Saturn's ring atmosphere and ionosphere

► We model the ring's O2 atmosphere with an source from Enceladus. ► No seasonal variability if recycling of Enceladus material is dominated. ► The scattered O2 could be an key supplier of O2+ in the magnetosphere at Equinox. ► This model needs Cassini CAPS and MIMI observations to be verified in future.