Observations of Active Region Dynamics: Preflare Flows and Field Observations

摘要

We have measured flows and magnetic fields at different heights in several activeregions. Quantities derived from the measurements include horizontal and vertical velocity fields, intensity fluctuations in the photosphere, temperature minimum region and low chromosphere, and the magnetic field in the photosphere. The observed regions typically flared one or more times during our observations. Primary observations were made with the Sacramento Peak Vacuum Tower Telescope (VTT) in combination with a narrow band (approx. 20 mA), tunable filter. Many of the observations have simultaneous vector magnetograrms obtained with the JHU/APL vector magnetograph (VMG) at the Hilltop complex at Sacramento Peak and were targets for the Yohkoh soft x-ray imager. Here, we discuss the relationship between flow fields. magnetic shear and flare kernels in two of the observed active regions. We find evidence that the location of flare kernels correspond to locations showing shear in the vertical and convergence in the horizontal photospheric flows. (AN).