海洋中生源活性气体的来源与迁移转化

Sources and transformation processes of biogenic active gases in the ocean

海洋生源活性气体主要包括二甲基硫(DMS)、甲烷(CH4)、氧化亚氮(N2O)、一氧化碳(CO)、挥发性卤代烃(VHCs)和非甲烷烃(NMHCs)等。它们通过海-气交换进入大气,不仅在全球碳、氮和硫循环中发挥关键作用,而且会直接或间接地对环境和气候变化产生重要影响。海洋释放的活性气体一类属于温室效应气体(CH_4、N_2O、VHCs和CO等),另一类会在大气中发生化学反应,控制着大气氧化平衡和臭氧浓度(VHCs和NMHCs)。而DMS属于负温室效应气体,其在大气中被快速氧化形成硫酸盐气溶胶,进而对云的形成和辐射强迫产生重要影响。本文综述了国内外海洋生源活性气体的研究现状,着重介绍了DMS、CH_4和N_2O的来源、迁移转化、海-气通量及其影响机制,并指明了该领域存在的科学问题及今后的研究方向。

Marine biogenic active gases mainly include dimethylsulfide(DMS),methane(CH 4),nitrous oxide(N 2O),carbon monoxide(CO),volatile halocarbons(VHCs)and non-methane hydrocarbons(NMHCs).These biogenic active gases are released into the atmosphere through the air-sea exchange and play critical roles not only in global cycling of carbon,nitrogen and sulfur but also in the direct and indirect influences on the climate and environmental changes.Some marine biogenic active gases belong to greenhouse gases(CH 4,N 2 O,VHCs and CO),and others would participate in chemical reactions in the atmosphere and control atmospheric chemical equilibrium and ozone concentration(VHCs and NMHCs).By contrast,DMS is a negative greenhouse effect gas.It will be rapidly oxidized to produce sulfate aerosol in the atmosphere and influence cloudy formation and the Earth’s radiative budget.The present research status of marine biogenic active gases is reviewed and the sources and sinks,sea-to-air fluxes of DMS,CH 4 and N 2 O as well as their influencing factors are summarized.Finally,some problems existing in the field and future research directions are presented.