Abstract We investigated the transformation processes of aerosol Fe in the surface water of the Northwestern Pacific Oceanic region by comprehensively collecting and measuring aerosols, seawater, size-fractionated suspended particles, and sinking particles during seasonally representative low and high aerosol deposition months. With one order of magnitude higher aerosol Fe contributed to the surface ocean in the spring month, the elevated deposition of aerosols was not reflected in the dissolved pool but the suspended pool. Elemental ratios further indicate that biotic and abiotic suspended particulate Fe exhibited size-dependent distribution patterns. Lithogenic particles originating from aerosol deposition were mainly in particle fraction with sizes ranging from 2 to 25 µm in the surface water. Biotic particles smaller than 2 µm were the major carriers of intracellular and surface precipitated/aggregated Fe. Due to the relatively small size and low density of biotic particles, the surface precipitated/aggregated Fe on small biotic particles shall possess longer residence time and higher bioavailability than the large and dense lithogenic particles in the euphotic zone.

中文翻译：

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西北太平洋表层水中气溶胶铁循环

摘要 我们通过对气溶胶、海水、粒径分级悬浮粒子和下沉粒子在季节性代表性的低、高气溶胶沉积月份进行综合收集和测量，研究了西北太平洋地区表层水中气溶胶Fe的转化过程。在春季，由于气溶胶 Fe 对表层海洋的贡献高出一个数量级，气溶胶沉积的增加并没有反映在溶解池中，而是在悬浮池中。元素比进一步表明生物和非生物悬浮颗粒 Fe 表现出尺寸依赖性分布模式。源自气溶胶沉积的成岩颗粒主要是地表水中粒径为 2 至 25 µm 的颗粒部分。小于 2 µm 的生物颗粒是细胞内和表面沉淀/聚集 Fe 的主要载体。由于生物颗粒的尺寸相对较小且密度较低，小生物颗粒上的表面沉淀/聚集的铁应比透光带中大而致密的成岩颗粒具有更长的停留时间和更高的生物利用度。