An electromagnetic wave is usually illustrated with two sine wave shaped fields, one for the electric field and one for the magnetic field. As in the picture below:
But as how I understand magnetism, it consists of two poles, north and south (alternatively described with field lines, with a direction, where north and south connects). So to focus only on the magnetic field (the red, B) in an electromagnetic wave; where are the poles located in such a sine wave (the red part)? Is only one of the poles illustrated, such that another sine wave could be added for the other pole?
Update: In this video, Maxwell's second equation is described as the field lines in the magnetic field is always connected (north and south pole) - how these field lines are organized in a wave is what I don't understand.
Later in the same video, the fields emitted from an antenna, are illustrated as "bubbles of fields" - quite different from how the "arrows/vectors" are illustrated in my picture above.