Effect of ion advection on the temperature (top) hydrogen (middle) and helium (bottom) profiles for the case of HD 97658 b. The dashed-dotted lines trace the profiles calculated neglecting the role advection, i.e., by solving the photoionization equilibrium equations in tandem with Euler equations, assuming stationary conditions; the solid lines illustrate how the profiles change when advection is implemented in post-processing, as described in Sect. 2.3. The relatively shallow ionization front in HD 97658 b renders this effect more extreme compared to other planets.