Single Spacecraft Tomography to Determine the Spatial Structure of the Magnetosheath Using Soft X-rays

The magnetosheath plays a central role in modulating the flow of mass, energy, and momentum from the interplanetary medium into the magnetosphere. Yet, the spatial and temporal properties of the magnetosheath under varying solar wind and possibly magnetospheric conditions remain largely unknown because empirical studies using in-situ observations are extremely challenging given the dynamic nature of the magnetosheath and its boundaries. Despite these challenges, global imaging of the spatial distribution of plasma properties in the magnetosheath is essential for determining energy transport into the magnetosphere. Soft X-ray imaging can provide the structure and plasma properties of the extended region beyond the magnetopause that imposes the outer boundary condition for the magnetosphere, the global magnetosheath [Sibeck et al. (2018), SSR, https://doi.org/10.1007/s11214-018-0504-7]. We discuss the application of tomographic reconstruction algorithms to line-of-sight soft X-ray emission observations to determine the spatial structure of the magnetosheath.