Ozone-Production

CO oxidation chemistry diagnostics from Seinfeld & Pandis (2006) Ch. 6 §6.3 Eqs. 6.9-6.18, pp. 212-219. CO oxidation is the simplest hydrocarbon-oxidation mechanism and illustrates the catalytic HOx cycling that drives tropospheric ozone production (net: CO + 2O₂ + hν → CO₂ + O₃, with OH regenerated through HO₂ + NO). This observed-only algebraic component implements six diagnostic relations: the OH loss rate L_OH (to CO, NO₂, O₃), the HO₂ loss rate L_HO2 (to NO, the HO₂ self-reaction, and O₃), the HOx radical-termination loss rate L_HOx (OH+NO₂→HNO₃ plus the HO₂ self-reaction), the high-NOx HO₂ steady-state concentration HO2_ss (Eq. 6.18), the net ozone production rate P_O3 (HO₂+NO production minus the OH+O₃ and HO₂+O₃ loss channels), and the HOx chain length (propagation rate over termination rate — the number of OH-HO₂ cycles before radical termination). Observed-only algebraic system (no time derivatives): twelve variables (six inputs CO/OH/HO₂/NO/NO₂/O₃ encoded as parameters, six outputs L_OH/L_HO2/L_HOx/HO2_ss/P_O3/chain_length as state), six rate-constant parameters (k_CO_OH, k_HO2_NO, k_HO2_HO2, k_OH_NO2, k_HO2_O3, k_OH_O3), one dimensionless stoichiometric constant (two), and six algebraic equations. Migrated from GasChem.jl@8c12c048 src/co_oxidation.jl:88 (`COOxidation` @component).

Methane oxidation reaction-rate diagnostics from Seinfeld & Pandis (2006) Ch. 6 §6.4, Table 6.1, pp. 219-227. Methane oxidation is the archetypal VOC oxidation mechanism in the troposphere, proceeding CH₄ → CH₃O₂ → CH₃O → HCHO → HCO → CO → CO₂. This observed-only algebraic component computes the 17 individual reaction rates R1-R17 of the complete Table 6.1 mechanism (10 bimolecular, 3 termolecular, 4 photolysis reactions) plus three diagnostic aggregates: the gross ozone production rate P_O3_gross = R15 + R3 (the two peroxy-radical + NO channels), the formaldehyde production rate P_HCHO = R6 + R8, and the methane loss rate L_CH4 = R1. Each reaction rate is the product of a 298 K rate constant and the reactant concentrations (R = k·[A]·[B] bimolecular, k·[M]·[A]·[B] termolecular, j·[A] photolysis). The fate of the methylperoxy radical CH₃O₂ — the O₃-producing NO channel R3 versus the chain-terminating HO₂ channel R4 — sets the ozone yield per CH₄ oxidized and is the central NOx-regime diagnostic of the mechanism. Purely algebraic (no time derivatives): 52 variables (15 input species and 17 rate constants encoded as parameters, 20 output diagnostics as state) and 20 equations. Migrated from GasChem.jl@8c12c048 src/methane_oxidation.jl:77 (`MethaneOxidation` @component).