Comparison of the forward modelling results with the observations. Panel a: STEREO A/COR2 white-light image of the streamer wave event on 6 February 2013. Panels b: Synthetic snapshot of the streamer wave propagation, obtained from the density data-cube based on the MHD simulation of the streamer wave phenomena. Here, the dark circle represents a patch to mask the distance below 2.0 R_⊙. The associated movie is available online.