Natural methyl bromide and methyl chloride emissions from coastal salt marshes.

摘要: Atmospheric methyl bromide (CH3Br) and chloride (CH3Cl), compounds that are involved in stratospheric ozone depletion, originate from both natural anthropogenic sources. Current estimates of CH3Br CH3Cl emissions oceanic sources, terrestrial plants fungi, biomass burning inputs do not balance their losses owing to oxidation by hydroxyl radicals, degradation, consumption soils, suggesting additional sources may be important. Here we show released the atmosphere all vegetation zones two coastal salt marshes. We see very large fluxes per unit area: up 42 570 micromol m(-2) d(-1), respectively. The diurnal, seasonal spatial variabilities, but there is a strong correlation between those CH3Cl, with an average molar flux ratio roughly 1:20. If our measurements typical marshes globally, they suggest such ecosystems, even though constitute less than 0.1% global surface area, produce 10% total atmospheric CH3Cl.