Measuring active region inflows with local correlation tracking
Björn Löptien (Max-Planck-Institut für Sonnensystemforschung), A. C. Birch (Max-Planck-Institut für Sonnensystemforschung), T. L. Duvall Jr. (Max-Planck-Institut für Sonnensystemforschung), L. Gizon (Max-Planck-Institut für Sonnensystemforschung, Institut für Astrophysik Göttingen), et al.

Active regions are surrounded by large converging inflows with typical velocities of 20-30 m/s that extend up to 10 deg around the active region. These inflows are important for the evolution of active regions because models suggest that they inhibit active region dispersal. The inflows have so far only been studied using local helioseismology. Here we study the flows around active regions by applying local correlation tracking of granulation on continuum intensity images provided by the Helioseismic and Magnetic Imager (HMI). We show examples of full disk Carrington maps of the horizontal flow velocity at the solar surface. These exhibit inflows to the active regions with the typical flow velocities and the radial extend being comparable to the results from local helioseismology.