Solar Force-free Magnetic Fields

Understand

The structure and dynamics of the solar corona is dominated by the magnetic field.

• In most areas in the corona magnetic forces are so dominant that all non-magnetic forces like plasma pressure gradient and gravity can be neglected in the lowest order.
• This model assumption is called the force-free field assumption, as the Lorentz force vanishes.
• This can be obtained by either vanishing electric currents (leading to potential fields) or the currents are co-aligned with the magnetic field lines.