SOHO Produces Images of Sunspot Interiors

Judebert writes: "The Solar and Heliospheric Observatory (SOHO, the one that looks at the Sun) has used a Doppler-like device to look underneath the surface of a sunspot. It turns out to be much shallower than expected, but the data does help explain why sunspots last so much longer than theory dictates. NASA's story is more informative, but the pictures and movies at Stanford are spectacular. I've got a new background!"

Comments

Field or Flow - which comes first?

[wnknisely]

"We discovered that the outflowing material was just a surface feature," said Zhao. "If you can look a bit deeper, you find material rushing inward, like a planet-sized whirlpool or hurricane. This inflow pulls the magnetic fields together."

The cool thing for me (and I confess upfront that I don't remember much about plasma flow in stellar atmospheres) is the question of which comes first now - the magnetic field disturbance or the plasma flow.

I know that a hot ionized plasma will freeze the magnetic field lines to the plasma - and that as the plasma moves it will drag the field with it.

So what's happening here? Is the magnetic field causing the whirlpool ala the Babcock model - or is there some sort of convention flow pulling the magnetic field along with it?

Anyone more current than I know?