Dynamics of the solar granulation - On the time variation of the granular flow

The emergence and evolution of large granules shows the granular dynamics p articularly well. We therefore investigate the time dependence of the conve ctive flows within a regular and an exploding granule. The observational ma terial for this study was taken at the center of the solar disk with the Ge rman VTT in Izana (Tenerife, Spain) during an observing campaign in the yea r 1994. It consists of series of spectrograms of high spatial resolution, w hich were digitized and processed with wavelet techniques. Among other feat ures, our data show the dynamical portrait of a regular and an exploding gr anule. We can follow their temporal evolution over more than 12 min. Using absorption lines of different strength we are able to see the dynamical cha nge of both granules at several heights within the first 200 km above tau ( 5000) = 1. The observations reveal significant changes of the convective fl ow of both granules over time as well as over height, which are discussed i n detail.