The 144° field-of-view Doppler images of the sky over Mawson. The right column shows F layer 630 nm Doppler images, the left column shows E layer 557.7 nm Doppler images on 10 June 2008. Each plot is labeled with UT. The optical intensity is not calibrated. The optical data are plotted in geographic coordinates with horizontal wind vectors overlaid for each zone (yellow). The wind vectors are centered on their measurement points. The vector for the zenith sector shows the average wind field, not the vertical wind. The top row (18:16 to 18:27 UT) shows before the arc appeared, the middle row (19:36 to 19:40 UT) shows when the arc appeared, and the bottom row (20:33-20:40 UT) shows after the arc disappeared. The blue box highlights the region of interest.