Author(s): , , , , ,
Institution(s): 1. Kyung Hee University, 2. Max Planck Institute for Solar System Research
Supersonic downflow patches was found in the outer edge of sunspot penumbra. These patches are believed to be the return channels of the Evershed flow. There was previous study to investigate their structure in detail using Hinode SOT/SP observations (M. van Noort et al. 2013) but their data sample was only two sunspots. To make general description it needs to check more sunspot data sample.
We selected 242 downflow patches of 16 sunspots using Hinode SOT/SP observations from 2006 to 2012. Height-dependent maps of atmospheric parameters of these downflows was produced by using HeLix which was height dependent LTE inversion code of Stokes profiles.
Statistical analysis of magnetic field strength, inclination angle of field line, temperature and line-of-sight velocity are presented. The recovered atmospheric data tell us that downflow patches have different physical signatures comparing normal penumbra properties. Furthermore, our results of three height-dependent layer support that heating process should occur on the downflow patches in the middle of layer.