In solar physics and observation, supergranulation is a pattern of convection cells in the Sun's photosphere. The individual convection cells are typically referred to as supergranules. The pattern was discovered in the 1950s by A.B. Hart[1] using Doppler velocity measurements showing horizontal flows on the photosphere (flow speed about 300 to 500 m/s, a tenth of that in the smaller granules). Later work (1960s) by Leighton, Noyes and Simon established a typical size of about 30000 km for supergranules with a lifetime of about 24 hours.[2]