Average formation depth, τ_afd, for the Hε spectral line. Top panels:τ_afd maps for the en simulation (panel a) and chb simulation (panel b). The orange contours indicate regions where Hε is strongly in emission, while the red contours indicate regions where Hα shows the typical signature of Ellerman bombs. For each panel, two inserts show a zoomed-in view covering the energetic events labeled earlier: an Ellerman bomb (EB), a UV burst (UVB), and two small flares (F1 and F2). The dashed white lines in the insets indicate the horizontal slices taken for the spectrograms of Figs. 1 and 2. Panel c: Distributions of log₁₀τ_afd. The emission distribution is amplified by a factor of six.