Final answer:
The pattern referred to in the question is known as solar granulation, which is the visible surface manifestation of convective cells on the Sun's photosphere.
Step-by-step explanation:
The large scale flow pattern on the surface of the sun, consisting of cells measuring up to 30,000 km across and thought to be the imprint of large convective cells deep in the solar interior, is called solar granulation. These surface markings are created by convection cells and are visible in images such as those taken from the Japanese Hinode spacecraft. The rice-grain-like structure of the solar photosphere is produced by upwelling currents of gas that are slightly hotter, and therefore brighter, than the surrounding regions which are moving downward into the Sun.