Figure 16-9: R I V U X G
Solar Granulation High-resolution photographs of the Sun’s surface reveal a blotchy pattern called granulation. Granules are convection cells about 1000 km (600 mi) wide in the Sun’s photosphere. Inset: Rising hot gas produces bright granules. Cooler gas sinks downward along the boundaries between granules; this gas glows less brightly, giving the boundaries their dark appearance. This convective motion transports heat from the Sun’s interior outward to the solar atmosphere.

(MSFC/NASA; inset: Goran Scharmer, Lund Observatory)