Authors: Bryan Yamashiro (University of Hawaii), Xudong Sun (University of Hawaii)

The Sun’s polar magnetic fields impart strong constraints on the internal dynamo process, the global coronal structure, and the origin of the solar wind. However, its absolute strength and fine-scale variation remain poorly measured. Furthermore, the extrapolated open magnetic flux, derived from photospheric magnetic field maps, is underestimated compared to the flux measured by in situ spacecraft. This phenomenon is commonly referred to as the “open flux problem” and introduces inaccuracies to the structure of global magnetic field models. Utilizing high-resolution Hinode spectropolarimetric observations and inversion algorithms, we address the systematic biases in magnetic field inference introduced by low spectral/spatial resolution, and explore a mismatch between the open magnetic fluxes estimated from the photosphere and in the solar wind. This study aims to provide a state-of-the-art contextual view of the polar magnetic landscape in anticipation of the upcoming high-resolution Daniel K. Inouye Solar Telescope and out-of-ecliptic space missions.