Magnetic Polarity Distribution and Evolution of an Active Region Moss Areas; a Case Study

Moss regions, that are the footpoints of the hot coronal loops and seen as the brightest emission areas in the EUV solar active regions with 1 MK temperatures, are studied in a quasi-steady phase of an active region with NOAA number 12010. Studying the moss regions are important to probe the heating mechanism(s) of the active region cores. Using the 193 Å extreme-ultraviolet (EUV) images of the AIA/SDO along with the magnetograms of HMI and employing the feature tracking code, YAFTA, the magnetic features of the HMI images are identified and tracked and the their locations are compared with respect to the positions of the selected moss regions. Results show that 68% and 32% of the moss areas are located over the borders and inside the magnetic patches, respectively. Moreover, 90% of the moss boxes are located above the uni-polarity magnetic regions that could be due to the low resolution and sensitivity of the HMI instrument. In continue three pairs of moss boxes at the opposite ends of the three hot coronal loops are selected and studied in more detail. Results show a global magnetic field increase at one end of the loop along with magnetic field decrease at the opposite side of the loops. Either a magnetic reconnection process near the flux cancelling leg of the loop, or a uni-directional siphon flow could be responsible to produce this behavior. Doppler- shift analysis is needed to distinguish which scenario is happening. Unfortunately, the spectral data are not present for these six moss boxes