A Space Mission for Cross‐Scale Coupling in the Earth's Magnetosphere

The Earth's magnetosphere occupies a huge volume in space. Past space missions have identified the basic structures and revealed several phenomena that release significant energy explosively. These activities are discovered through point‐wise measurements in space. Consequently, there is a severe lack of knowledge on the coupling between different activities. A space mission that can address this deficiency is proposed here, building on what previous space missions have revealed. A fleet of eight identical spacecraft in two sets of tetrahedral constellations will enable evaluation of how localized kinetic activities may lead to global changes and vice versa in the Earth's magnetosphere. This mission uses the full capability of a tetrahedral constellation to yield a quantitative determination of physical parameters that govern the mass, momentum, and energy flows between space disturbances at kinetic and global scales. It will also resolve the ambiguity in single‐point measurements to differentiate their temporal and spatial variations. Examples on how to use this mission to extract cross‐scale coupling of activities and tackle outstanding questions in magnetospheric research are discussed. Plain Language Summary Previous space missions focus on individual events that occur at the spacecraft location without addressing specifically how local activity and global activity are linked. This missing link in achieving the next level for understanding space disturbances is addressed by the proposed mission, which is a natural follow up from previous space missions. It uses eight identical spacecraft in two sets of tetrahedral constellation to evaluate quantitatively the physical parameters that govern the flow of mass, momentum, and energy between disturbances in various sizes. Deeper understanding of these phenomena in local or global scale will be gained with this mission for accurate forecasting and efficient mitigating their impacts that may affect our daily routines and lives. Examples to use the mission to extract the nature of coupling between disturbances at different scales and to solve outstanding research questions are also discussed. Key Points A missing link in achieving the next level of understanding space disturbances from previous space missions is identified The proposed mission will address this deficiency in linking local and global disturbances by two cluster sets of four spacecraft The cross‐scale coupling between local and global disturbance