Authors: Kevin Brooks, Sushant Mahajan, James McAteer, Jason Jackiewicz

As multiple missions prepare to explore the solar poles, establishing a baseline from existing datasets is critical to contextualize future observations. However, the Sun’s curvature and reduced resolution near the poles, compounded by distortions from commonly used projection algorithms, pose significant challenges. We investigate artefacts introduced by these algorithms—such as bi-cubic and spline interpolation methods—in polar data from the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). These distortions obscure key features, complicating analyses of rotation rates, meridional flows, and polar dynamics. By quantifying the impact of various interpolation techniques, we identify their limitations and propose mitigation strategies to enhance data fidelity near the poles. Our analysis reveals that improved projections can better resolve small-scale structures, providing a clearer picture of polar behavior. Notably, we detect long-lived circumpolar features—potentially the first observed in solar physics—that persist long enough to encircle the poles. These features, identified in magnetograms, suggest unique dynamics at high latitudes, possibly linked to polar magnetic field evolution or subsurface flows. This discovery underscores the need for refined data processing to unlock the full potential of current archives. Our findings establish a foundation for interpreting polar observations from upcoming missions like Solar Orbiter and pave the way for advanced studies of solar polar phenomena.