Recombination and advection for HD 209458 b, HD 189733 b, and GJ 3470 b. Upper row: production rates of H by recombination (solid lines) and advection (dashed lines) derived from the fits of the measured He(2³S) absorption spectra (see symbols in Fig. 1) in the atmospheres of HD 209458 b (left), HD 189733 b (middle), and GJ 3470 b (right) and the representative H/He ratios of 98/2, 99/1, and 98/2, respectively. Lower row: ratios of the recombination to the advection. The vertical dashed orange lines indicate the mean Roche lobes. The different scales of the x and y axes for the different planets should be noted.