From our single vantage point of Earth, our view of the Sun is never complete. While the far-side of the Sun eventually rotates into view, coverage of the Sun's polar regions is never satisfactory as perspective effects either completely block our view or create a distorted view. We must often resort to computer modeling of these solar polar regions.
This visualization presents the Potential Field Source Surface (PFSS) magnetic field model based on solar observations covering the years 2017-2019. One version also presents the 'hole' in our measurements of the solar polar region. The region oscillates in size over the course of the year due to the changing perspective created by the tilt of Earth's orbital plane with the solar equator. In this region, researchers must resort to approximations to build a more complete view of the solar magnetic field.
Why is the solar magnetic field in this region important? Because the combined with the outgoing flow of the solar wind, the magnetic field lines from the polar regions curve up, and then back down to near the Sun's equatorial plane, which is still fairly close to the orbital plane of Earth and other planets in our solar system. This gives the Sun's polar magnetic field a significant influence on the space weather impacting Earth and crewed and uncrewed assets around the solar system.
This movie gives a view starting at equator and tipping to a view of the north heliographic pole (the blue axis) then dipping down to the south heliographic pole. Closed field lines are white/grey, green and violet lines represent field lines that are considered 'open'. Green represents positive magnetic polarity, and violet represents negative polarity. The dark rings around the blue polar axis show the region where the solar surface magnetic field must be generated from a model. This region grows and shrinks depending on SDOs position in its orbit around the Sun and Earth (above and below the solar equator, which is tilted by 7.25 degrees relative to Earth's orbital plane).