Morphological study of the solar granulation

Abstract

A time sequence of granulation images of 46 min long has allowed us to make a detailed study of the evolution of granules in an area of approximately 17″ × 17″ on the solar surface. It is found that the granules evolve by repeated fragmentation into smaller granules or merging with adjacent ones and that there are few granules which appear in the intergranular lanes as new granules (Table III). The statistical nature of granules is as follows:

• (1) A family of granules is defined as a group of granules produced from a single granule by fragmentation or merging. The lifetime is estimated for single granules and for families of granules. The lifetime shows a close correlation with the maximum size of a single granule or with that of the largest granule belonging to a family (Figures 5 and 7).

• (2) The smaller the size, the more probably a granule will disappear without further fragmentation or merging. The granule whose size is larger than 2″ will certainly split or merge as the next evolutional step (Table IV).