Schematic drawing of the possible scenario for the wave formation. (a) Relationship between the EUV wave (the deep blue shade) and the SAs, overlaid on the HMI vector magnetogram at ∼16:36 UT. The magnetic structures in the source AR are the same as those in Fig. 1c. (b) The possible scenario for the expansion (purple arrows) of the releasing strands of SAs (the dashed green-blue line) in a side view. The yellow arrow points out the possible sites of magnetic reconnection.