When sun spots are active they cause heating in the upper atmosphere, which in turn causes expansion. Skylab fell to earth prematurely in 1979 due to this phenomenon when an unexpected Sun Spot flared up. The launch of the Hubble telescope was delayed for a year because of Sun Spot activity. Volume visualization of the data was created by John Clyne, of NCAR, using Volsh . In the visualizations below, the variable that is depicted is magnetic pressure.
Magnetic pressure is defined as the strength of the magnetic field, squared.
Brighter colors represent higher pressure. There is an inverse relationship between gas pressure and magnetic pressure. At the beginning of the animation you are seeing the ends of the stable stage. The pore in front, center is beginning to go unstable, as indicated by the formation of the two lobes in the blue areas. As the evolution progresses these twin lobes, which are characteristic of the unstable stage, become more and more distinct.