Properties of Chromospheric Flow Channels Around a Sunspot

We report the properties of chromospheric flow channels connecting the leader spot of the decaying active region NOAA 12418 with the nearby moat and plage locations. The observations were carried out on 2015 September 16 with the Interferometric Bidimensional Spectrometer (IBIS) and the Facility Infrared Spectropolarimeter (FIRS) at the Dunn Solar Telescope. They consist of IBIS sequential scans in two chromospheric spectral lines of Hα at 656 nm and Ca II IR at 854.2 nm in its spectroscopic mode. FIRS recorded vector spectropolarimetric data of the He I line at 1083 nm. The ground-based data are complemented with the Milne-Eddington inversion results for the photospheric magnetic field derived from observations by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory that were used in a non-linear force-free magnetic field extrapolation. We find that the flow channels originate in the mid to outer penumbra and connect to magnetic field concentrations inside and at the end of the moat cell. Shorter fibrils carry the common inverse Evershed Flow. Longer filaments have a longer life time and permanently exhibit a strongly reduced intensity and fast flows along a large part of their length. In this contribution we present details on the internal substructure of the temperature, magnetic and flow structure of these different flow channels. We were able to identify a siphon flow mechanism as driver for the regular inverse Evershed flow.