PHENOMENA IN AN EMERGING ACTIVE-REGION .1. HORIZONTAL DYNAMICS

Horizontal dynamics in observations of NOAA AR 5617 are studied by tra cking individual elements through the field of view. Small magnetic el ements of both magnetic polarities occur everywhere in the active regi on, and define unipolar thread-like concentrations of magnetic field o f up to 15 Mm length. The horizontal granular flow field in the active region is divergent (e-time scale 2.1 hours) and clockwise (time scal e 32 hours). Facular elements are tracers of (clumps of) fluxtubes. A hierarchy of movement of magnetic elements appears: Facular elements e verywhere in the active region move obliquely toward the edges of the active region of the same polarity as their own, faster than those edg es (as defined by strings of pores) move apart. The pores move along t he edges toward the major sunspots of their own polarity, and the majo r sunspots of either polarity move apart. The separation velocity of b oth polarities of facular elements is about 0.84 km/s, of pores about 0.73 km/s, and that of the major sunspots is about 0.50 km/s.