Aqueous_phase

Full cloud chemistry system with pH computed from the electroneutrality condition — Seinfeld & Pandis (2006), Ch. 7. The model composes AqueousEquilibria (quadratic charge-balance H⁺ from dissolved CO2, SO2, NH3, HNO3, H2O2, and O3 equilibria) with SulfateFormation (S(IV) oxidation kinetics via O3, H2O2, and Fe/Mn pathways). Unlike CloudChemistryFixedpH, which prescribes H⁺ from an external pH_input, this model self-consistently solves for the cloud-water pH from the trace-gas composition. Migrated from Aerosol.jl@c8c640bb src/cloud_chemistry.jl:73.

Simplified cloud chemistry system with pH as an externally prescribed input parameter — Seinfeld & Pandis (2006), Ch. 7. Instead of computing pH from the electroneutrality condition (as in the full CloudChemistry model), this variant takes pH_input as an input and derives H_plus = C_ref × 10^(-pH_input). This is useful for sensitivity studies that vary pH, for cases where unmeasured ions affect pH, or for quick calculations that bypass the full equilibrium solve. The model composes seven aqueous-equilibrium subsystems (WaterEquilibrium, CO2Equilibria, SO2Equilibria, NH3Equilibria, HNO3Equilibria, H2O2Equilibria, O3Equilibria) and the SulfateFormation oxidation kinetics module (O3, H2O2, and Fe/Mn-synergism pathways). All equilibria use van't Hoff temperature dependence from Table 7.4. Migrated from Aerosol.jl@c8c640bb src/cloud_chemistry.jl:269.

Dynamic cloud droplet chemistry: time evolution of sulfate concentration as S(IV) is oxidized to S(VI) via O3, H2O2, and Fe/Mn-catalyzed pathways (Seinfeld & Pandis 2006, Chapter 7, Eqs. 7.79-7.102). Gas-liquid equilibria (SO2, H2O2, O3) are assumed instantaneous; the sulfate ODE tracks the kinetic accumulation. Migrated from Aerosol.jl src/cloud_chemistry.jl:422.