Equilibrium partial pressures of CO₂ (dark blue) and NH₃ (green) in Titan’s primordial atmosphere as a function of the total NH₃ dissolved in the ocean. Each set of green and blue curves, distinguished by different line styles, represents a specified initial CO₂ atmospheric pressure prior to chemical equilibrium between the ocean and atmosphere. The initial theoretical P_CO2 values of 1, 5, 10, 20, and 30 bar correspond to CO₂ bulk masses of 7.8 × 10¹⁹ kg, 3.79 × 10²⁰ kg, 7.38 × 10²⁰ kg, 1.37 × 10²⁰ kg, and 1.92 × 10³⁰ kg, and a dissolved CO₂ mole fraction of 1.36 × 10⁻³, 6.78 × 10⁻³, 1.36 × 10⁻², 2.71 × 10⁻², and 4.07 × 10⁻², respectively.