Mn, Fe and I Redox Chemistry and Their Role in Organic Matter Decomposition in the Arabian Sea

9310792 Luther在阿拉伯海，由于其水循环受到三面陆地块的限制，季风驱动的初级生产和衰减的季节性模式与地表水的强烈加热相结合，促进了广泛的低氧水地下区域的形成——氧最小区（OMZ）。在含氧海洋表面产生的微粒有机物质下沉到无氧区，在那里它可能被微生物利用，这些微生物利用氧气以外的来源——即溶解的硝酸盐、铁、锰、碘酸盐——进行呼吸。作为美国jgofs阿拉伯海过程研究的一部分，研究人员将调查铁、锰和碘氧化还原对在这一过程中所起的作用。这样的研究将有助于回答两个更大的海洋学问题：OMZ如何影响碳循环？厌氧过程在OMZ中占主导地位吗？通过在一系列站点对OMZ附近的水柱进行采样，并将浓度数据与垂直和水平传输速率的水文数据耦合到数学反应-传输模型中，研究人员将估计这些鲜为人知的氧化途径在有机碳氧化的区域图景中有多重要。＊＊＊

9310792 Luther In the Arabian Sea, with its water circulation constrained by land masses on three sides, the seasonal pattern of primary production and decay driven by the monsoon winds couples with intense heating of surface water to promote formation of an extensive subsurface zone of low-oxygen water--the oxygen minimum zone (OMZ). Particulate organic matter produced in the oxygenated surface ocean sinks into the OMZ, where it may be utilized by microbes that use sources other than oxygen -- namely, dissolved nitrate, iron, manganese, iodate -- for respiration. As part of the U.S.JGOFS Arabian Sea Process Study, the investigators will investigate the role played by iron, manganese, and iodine oxidation-reduction couples in this process. Such a study will contribute to answering two larger oceanographic questions: How does the OMZ influence carbon cycling? Do anaerobic processes dominate in the OMZ? By sampling the water column in the vicinity of the OMZ at a series of stations and coupling concentration data with hydrological data on vertical and horizontal transport rates into a mathematical reaction-transport model, the investigators will estimate how important these minimally understood oxidation pathways are in the regional picture of organic carbon oxidation. ***