Measurements of Frequencies of Solar Oscillations from the
MDI medium-l Program
by E.J. Rhodes, Jr., A.G. Kosovichev, P.H. Scherrer, J. Schou & J. Reiter
Fig. 1c: Full disk Dopplergram.
Full-disk Dopplergram obtained with MDI on 9 July 1996.
The large left-right variation is the signal from solar rotation.
The "texture" is a combination of the motion from the sound waves
that permeate the Sun and the large convective cells called
"super-granulation". The bright feature in the lower right quadrant
is an active region.