Journal: Nature Communications

Article Title: The Sun as a driver of the inner heliosphere: Modern investigations of fundamental plasma processes

doi: 10.1038/s41467-026-72082-8

Figure Lengend Snippet: Panel a shows a combination of models and observations in the near-Sun environment (black box region in the cartoon on the right surrounding the Sun). The top left quadrant is a model of the solar interior showing internal flow (differential rotation, meridional circulation probed via helioseismology), coupling with the magnetic field constituting the solar dynamo. The bottom left quadrant is a ground-based (GONG) observation of the photospheric magnetic field. Magnetic field lines from a Potential Field Source Surface (PFSS) extrapolation are overlaid. The right quadrant shows observations from the extreme ultraviolet imager (EUI) aboard Solar Orbiter in 174 Å ( top right ) and 304 Å ( bottom right ), which show emission from the corona and chromosphere, respectively. These are inset on a volume rendered Q-map (squashing factor), a quantification of the global magnetic field structure and separatrix web, from a time-dependent magnetohydrodynamic (MHD) simulation of the solar corona (Credit: Predictive Science Inc. 42 ). Both the PFSS and MHD models used observations of the photospheric magnetic field as an inner boundary condition, an example of how observations drive coronal models. The bottom right of the inset shows a cartoon of magnetic reconnection associated with an active region structure. Panel b shows a heliospheric system overview of the inner-heliospheric spacecraft (discussed in this paper) taking remote and in-situ observations of the Sun and solar wind, alongside the Alfvén surface, a cartoon CME, switchback, solar wind outflow, HCS, and representative velocity distribution function (VDF, measured from PSP 43 ). We highlight some of the proposed heating mechanisms in the top left inset. We note that there are many more spacecraft from different space agencies making measurements that can help answer the open questions discussed in this comment; we chose to show the ones discussed in the text.

Article Snippet: Results of the time-dependent coronal magnetic field model used to produce the background map of the Sun in the Figure can be found at https://zenodo.org/records/14889337 courtesy of Cooper Downs at Predictive Science Inc.

Techniques: In Situ