Intensity image from SDO 193 Å (panel a)) and Doppler velocity from CoMP (panel b)). The dashed lines above the limb (at a height 1.09 R_⊙) in both panels are used to make Fig. 3. The arc sector in the top right of panel a) shows the region used to get the density of the quiet Sun in Sect. 5.1. Note that the intensity image in panel a) has been enhanced using the Multi-scale Gaussian Normalisation technique of Morgan & Druckmüller (2014). The evolution of the 193 Å channel is shown in the left panel of the movie available online.