In the image to the right, you can see a charged particle spiraling around a magnetic field line. This is what solar plasma does when a magnetic field line pops out of the sun's surface and invisibly arcs and returns. The dark pairs of umbra in a sunspot usually represent the exit and entrance points of a field line where the surface cools. Beneath the surface, field lines may be twisted to the point of shear, or stretching out from the surface until they bow and reconnect. Particles whirling about the field lines can be flung out of the sun's gravitational and magnetic fields, an oxbow of matter, when the magnetic field line they are riding on reconnects below them.
In a way, I don't feel too bad about just figuring out now what being a plasma means magnetically and being curious about its effects on the earth. Scientists are researching the same things that I am curious about. Since they can't SEE magnetic field lines, they have to watch the actions of the sun's plasma caught in magnetic fields. NASA's sun research is burgeoning. NASA launched the STEREO mission to watch the sun from different angles to capture such plasmic movement. In a study published just this year, they were able to visually catch the 3D field slippage and reconnect of a flare, showing how (perhaps all?) solar flares begin. [4]
http://galacticinteractions.scientopia.org/2012/02/09/charged-particles-and-magnetic-fields/