ON THE DYNAMICS OF SMALL-SCALE SOLAR MAGNETIC ELEMENTS

We report on the dynamics of the small-scale solar magnetic field, bas ed on analysis of very high resolution images of the solar photosphere obtained at the Swedish Vacuum Solar Telescope. The data sets are mov ies from 1 to 4 hr in length, taken in several wavelength bands with a typical time between frames of 20 s. The primary method of tracking s mall-scale magnetic elements is with very high contrast images of phot ospheric bright points, taken through a 12 Angstrom bandpass filter ce ntered at 4305 Angstrom in the Fraunhofer ''G band.'' Previous studies have established that such bright points are unambiguously associated with sites of small-scale magnetic flux in the photosphere, although the details of the mechanism responsible for the brightening of the fl ux elements remain uncertain. The G band bright points move in the int ergranular lanes at speeds from 0.5 to 5 km s(-1). The motions appear to be constrained to the intergranular lanes and are primarily driven by the evolution of the local granular convection flow field. Continua l fragmentation and merging of flux is the fundamental evolutionary mo de of small-scale magnetic structures in the solar photosphere. Rotati on and folding of chains or groups of bright points are also observed. The timescale for magnetic flux evolution in active region plage is o n the order of the correlation time of granulation (typically 6-8 minu tes), but significant morphological changes can occur on timescales as short as 100 s. Smaller fragments are occasionally seen to fade beyon d observable contrast. The concept of a stable, isolated subarcsecond magnetic ''flux tube'' in the solar photosphere is inconsistent with t he observations presented here.