supergranulation
Original archive entry. The text, images and links below are kept as they were written.
A net-like pattern of irregular cells, 15,000 km (800 naut. ml.) to 40,000 km (22,000 naut. ml.) in diameter, superimposed upon the photospheric granulation network, and caused by plasma convection within the chromosphere. Cell lifetime is about 20 hours. Supergranulation is best observed in the monochromatic light of a calcium spectral line.