Sulfur Hazes in Giant Exoplanet Atmospheres: Impacts on Reflected Light Spectra

Recent work has shown that sulfur hazes may arise in the atmospheres of some giant exoplanets, due to the photolysis of H2S. We investigate the impact such a haze would have on an exoplanet's geometric albedo spectrum and how it may affect the direct imaging results of the Wide Field Infrared Survey Telescope (WFIRST), a planned NASA space telescope. For temperate (250 K < Teq < 700 K) Jupiter-mass planets, photochemical destruction of H2S results in the production of ∼1 ppmv of S8 between 100 and 0.1 mbar, which, if cool enough, will condense to form a haze. Nominal haze masses are found to drastically alter a planet's geometric albedo spectrum: whereas a clear atmosphere is dark at wavelengths between 0.5 and 1 m, due to molecular absorption, the addition of a sulfur haze boosts the albedo there to ∼0.7, due to scattering. Strong absorption by the haze shortward of 0.4 m results in albedos