A convection pattern in the Sun’s photosphere, consisting of convection cells 30 000 km wide that are much larger versions of normal granules. There is a slight upward flow at the cell’s centre, a mainly horizontal flow outwards, and a subsequent downward flow at the cell’s edges. The velocity of the horizontal flow is only 0.4 km/s, a fraction of that in granules. A typical lifetime of a supergranule cell is a day. Small areas of strong magnetic field are transported outwards from cell centres to the edges, where the field is mostly concentrated. This appears to give rise to the chromospheric network, consisting of clumps of spicules.