Jupiter wind as a unifying bridge: a testable paradigm in the Tianwen-4 era

Jupiter's rotating magnetic field, together with its satellites and rings, generate a composite flow that we term the Jupiter wind in this paper: a multi-source mixture of particles originating from Io's volcanism, Jupiter’s other moons, its rings, and its atmosphere, subsequently reprocessed by ionization, acceleration, corotation, and outward and tailward transport. Inspired by the unifying role of the solar wind in heliophysics, we argue that a Jupiter wind perspective can similarly integrate disparate domains of Jovian science—interior structure, Io's volcanic activity and neutral cloud, plasma dynamics, radiation belts, and distant magnetotail evolution—into a coupled evolutionary framework. We highlight three systematically interconnected knowledge gaps that form a coherent investigative chain: (1) What are the electromagnetic processes inside Io, influencing the fundamental source characteristics of Jupiter wind? (2) What quantitative role do neutral particles play in processes such as supplying the inner radiation belt, representing the intermediate processing stage of Jupiter wind evolution? (3) How do magnetic field and charged particles evolve across the distant (~100 R_J to > 9000 R_J) magnetotail, concerning the ultimate fate and control mechanisms of Jupiter wind? The forthcoming Tianwen-4 mission—potentially synergistic with JUICE and Europa Clipper, if their operations overlap—offers a unique opportunity to deliver instruments to investigate magnetic field and charged and neutral particles, enabling testable predictions regarding the source and evolution of Jupiter wind. Framing Jupiter wind within a generalized "planet wind" paradigm may ultimately clarify how internal driving competes with solar forcing to shape planetary systems across the solar system and beyond.