SDO OBSERVATIONS OF MAGNETIC RECONNECTION AT CORONAL HOLE BOUNDARIES

With the observations from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) aboard the \emph{Solar Dynamics Observatory}, we investigate the coronal hole boundaries (CHBs) of an equatorial extension of polar coronal hole. At the CHBs, lots of extreme-ultraviolet (EUV) jets, which appear to be the signatures of magnetic reconnection, are observed in the 193 {\AA} images, and some jets occur repetitively at the same sites. The evolution of the jets is associated with the emergence and cancelation of magnetic fields. We notice that both the east and the west CHBs shift westward, and the shift velocities are close to the velocities of rigid rotation compared with those of the photospheric differential rotation. This indicates that magnetic reconnection at CHBs results in the evolution of CHBs and maintains the rigid rotation of coronal holes.
Comment: 10 pages, 5 figures, accepted for publication in ApJL