ocr: MDI These are solar sounds generated from 40 doys of MDI data. lo bring these sounds into the audible human- hearing ronge is accomplished by speeding up the data rate by a factor 42,000. (One must realize that solar sound waves have very low trequencies corresponding to periods from minutes to hours while human, ears hear sound wave periods of milliseconds) u-disk Dopplergram Because the Sun rotates, one side is com- a sely BE 202a0 ing toward US at 2 km/s and the other is going away. The figure is a map of the speed of the Sun's surface as measured by the MDI instrument; the colors indicate ...
