Characterization of emissions of biogenic atmospheric hydrogen sulfide

The emission rate measurements of H2S into the atmosphere from coastal marine sediments were made by the use of an emission flux reactor (chamber) technique under deaerated (gaseous N2) and aerated (ambient air) conditions. The emission rates of H2S varied over a wide range (>0.05 to < 100 gS m-2 yr I ) . The emission of H2S was inversely related to the stage of tidal hydrology, with incoming and outgoing tidal hydrostatic pressure affecting the gaseous release at the locale. The diurnal studies showed an enhancement in the emission rates at night; however the emission rate of H2S is unaffected by increasing light intensity (between 100 and 90,000 lux) at constant temperature. The emission rates of H,S are greater in the deaerated chamber than in the aerated chamber. The measured marine fluxes of -0.1 gS m-2 yr-! seem to agree well with those derived from global marine sulfur budgets.