Parker instability

Summary

The Parker instability is an instability of a stratified gas layer that is supported against gravity partly by a horizontal magnetic field. If the field lines are bent into waves, the gas slides down along them into the valleys. The crests become lighter, and magnetic buoyancy lifts them further. It is a form of magnetic buoyancy instability in magnetohydrodynamics. It is thought to gather interstellar gas of the galactic disk into clouds and to help magnetic flux rise through the Sun.