A mini-chemical scheme with net reactions for 3D general circulation models

Context. Growing evidence has indicated that the global composition distribution plays an indisputable role in interpreting observational data. Three-dimensional general circulation models (GCMs) with a reliable treatment of chemistry and clouds are particularly crucial preparing for upcoming observations. In attempts to achieve 3D chemistry-climate modeling, challenge mainly lies expensive computing power required treating large number chemical species reactions. Aims. Motivated by need robust computationally efficient scheme, we devise mini-chemical network minimal reactions H 2 -dominated atmospheres. Methods. We apply novel technique simplify from full kinetics model, VULCAN, replacing intermediate net The is cut down 67 12, major thermal importance retained, including O, CH 4 , CO, CO C NH 3 HCN. size total also greatly reduced, ~800 20. validated scheme verifying temporal evolution benchmarking predicted compositions four exoplanet atmospheres (GJ 1214b, GJ 436b, HD 189733b, 209458b) against VULCAN. Results. mini-network reproduces timescales distributions well within order magnitude pressure range 1 bar–0.1 mbar across various metallicities carbon-to-oxygen (C/O) ratios. Conclusions. have developed using significantly network. small scale permits simple use fast computation, which optimal implementation GCM or retrieval framework. focus on thermochemical this paper address photochemistry follow-up paper.