Velocities in Solar Pores

Abstract

We use high spatial and spectral resolution filtergrams to examine the three-dimensional morphology and velocity fields associated with solar pores in a region of newly emerged magnetic flux. The observed amplitude of the horizontal surface velocities decreases near the pores. Most of the pores exhibit a downflow in the surrounding region. Time-averaged line-of-sight velocities in and near the pores increased with the strength of the associated magnetic field. The LOS velocities are such that the maximum downflow is not centered about the continuum intensity and sometimes traces an annulus ringlike structure around the pore. From a time sequence of continuum images, it appears that some pores shed flux at the photospheric level. "Cork movies" of the surface velocities show that the "corks" are advected toward weak downflows near the pore locations and that the loci of the advected corks trace boundaries that resemble mesogranular and supergranular flows. We analyze the vertical velocity structure in pores and show that the downflow decreases exponentially with height, with a scale height that is a factor of 2 smaller than the photospheric scale height for granules. The line-of-sight flow associated with the pores appears to expand with height. Our observations are compared with previous measurements of flows in and around pores that were based on both spectrograms and filtergrams. Finally, we provide a phenomenological description for pores.