Trace H2S Promotes Organic Aerosol Production and Organosulfur Compound Formation in Archean Analog Haze Photochemistry Experiments

Abstract Organic haze and sulfur gases are ubiquitous in planetary atmospheres and were likely present in Earth's Archean atmosphere. Currently, there are few experiments investigating how H 2 S influences organic haze chemistry on Archean Earth. Here, we present results from laboratory haze‐analog experiments probing the role of H 2 S in the composition and total mass of aerosol produced from precursor mixtures of Archean‐like gas fluxes (e.g., pCO 2 ∼3–50xPAL). We show that trace H 2 S enhances organic aerosol production at all carbon dioxide mixing ratios studied, and we observe both organic and inorganic sulfur aerosol products. Our finding challenges predictions that H 2 SO 4 and S 8 were the primary sulfur reservoirs in Earth's Archean atmosphere, and these results suggest that inorganic sulfur and organic haze chemistry are tightly coupled during the formation of organic hazes in the atmospheres of the Archean Earth and likely Archean‐like exoplanets.