Representation of the characteristic parameters of the atmosphere. In the top panel, the density of neutrals is in solid black line and the density of charges is in dashed-dotted line. Their scale is shown on the left axis. The right axis labels represent the neutral-charge (solid red line) and the charge-neutral (dashed-dotted red line) collision frequencies. The characteristic speeds are displayed in the bottom panel: the neutral (solid black line), charge (dashed line) and 1F (dashed-dotted green line) sound speeds and the 1F (solid yellow line) and charge (‘dashed-dot’ yellow line) Alfvén speeds. The vertical dashed line indicates the equipartition layer β_plasma = 1.