Histograms of sampling delays for data A (left) and data B (right). The latter cover a twice longer delay range than shown here. Upper row: delays corresponding to the image pairs in Fig. 12, positive for darkest line-core occurrence after darkest blue-wing occurrence per network pixel, and negative for darkest core before darkest wing occurrence. Lower row: delays between the darkest blue-wing occurrence and the second-darkest blue-wing occurrence per network pixel. The delays are color-coded as in Fig. 12. The gray rectangles mark the [−2, +2] min ranges without delay determinations. The bin widths are 1 min. The y-axes specify numbers of pixels per bin as fraction of the network area.