Whitepaper #416 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: inner heliosphere; solar physics.
The Sun and the heliosphere is a system-of-systems, where the physics of cross-regional and cross-scale coupling determines the state of the system. We describe the outstanding questions of solar wind physics as well as potential solutions, including the need for coordinated observations, modeling, and data architecture under an umbrella program such as ISTPNext.