Romashets and Vandas (2024) derived a method for the determination of Euler potentials at a spherical surface and applied it to the geomagnetic field. Here, we apply it to find Euler potentials at the source surface. A regular mesh defined by Euler potentials divides the source surface to surface elements with the same magnetic flux. By tracing magnetic-field lines away from the source surface, Euler potentials can be extended into the heliosphere.
