Magnetic fields (red/black) and sub-surface currents (arrows)

The Michelson Doppler Imager, from Stanford University, on board the ESA/NASA SOHO spacecraft, maps flows of sub-surface currents of gas, equivalent to the deep ocean currents on Earth.

It reveals how hot gas rising from the deep interior can be throttled by magnetic whirlpools to create the relatively cool dimples in the surface that we see as dark sunspots.