Sensitivity of abiotic oxygen and ozone buildup to redox sources and sinks

Determine how sensitive the abiotic O2 and O3 buildup behavior in Archean Earth-like atmospheres orbiting ultraviolet-emitting M stars is to varying assumptions about atmospheric and oceanic redox sources and sinks.

Background

The paper models abiotic O2 and O3 accumulation in CO2-rich, relatively anoxic Archean Earth-like atmospheres exposed to M-star ultraviolet radiation. The authors impose global atmospheric-plus-oceanic redox balance and argue that their modeled buildup is not an artifact of redox imbalance because the simulated oxidizing fluxes are within plausible early-Earth limits.

Nevertheless, the strength of the buildup may depend on assumptions about the allowable reducing flux at the ocean–mantle boundary and the surface deposition velocities of reducing gases such as CO. The authors explicitly leave unresolved how changing these redox boundary conditions would alter the predicted O2 and O3 accumulation.