Interplanetares Magnetfeld

Like the Earth, the Sun also has a magnetic field. However, this solar magnetic field does not end at the solar surface but extends into the realm of the planets. It is carried into this interplanetary space with the solar particles of the solar wind, which is why it is also referred to as the interplanetary magnetic field (IMF). At the edge of the solar system, the solar wind encounters the interstellar medium with its own, the interstellar, magnetic field. Here at the heliopause, the non-gravitational influence of the Sun ends. A particular periodicity of the interplanetary magnetic field arises due to the solar rotation. This draws the footpoints of the magnetic field lines with it during its rotation, while the actual field lines run radially into the outer solar system with the solar wind. This ultimately results in a spiral image of the IMF, known as the Parker spiral, often compared to a lawn sprinkler. The solar magnetic field is a "normal" dipole field. However, this is somewhat chaotically altered by sunspots, each bringing their own magnetic structure. In a projection of the IMF into the plane of the planets (ecliptic), field lines with north or south polarity are not represented; instead, the magnetic flux direction at the footpoints of the field lines is considered. If the flux exits the solar surface, it is referred to as "away" field lines, marked red in the following diagrams. Analogously, incoming field lines are labeled "toward" and marked in blue. In this diagram, only the field lines that can interact with the Earth's magnetic field are considered, resulting in a sectorization of the Parker spiral into corresponding red and blue areas due to local structures like sunspots and coronal holes. This can vary from just one blue and one red area to several blue and red areas, depending on how active the Sun is and how chaotic the structures near the solar equator are.