Dissolved lignin phenols, chromophoric dissolved organic matter (DOM), and in situ fluorescence were determined in waters of the Laptev Sea and major Arctic basins, and they were compared with dissolved iron (dFe) distributions to elucidate the sources, molecular characteristics and distributions of iron-binding ligands in the Arctic Ocean. In the Transpolar Drift region (TPD), concentrations of dFe were positively correlated with concentrations of lignin phenols and multiple optical proxies of DOM composition and source. Strong relationships between dFe and visible and ultraviolet wavelength fluorescent DOM indicated that vascular plant and algal-derived DOM contributed to the dFe-ligand pool. These observations are consistent with previous studies suggesting the association of dFe with humic terrigenous and marine organic ligands. The primary sources of iron-binding ligands appear to be the riverine discharge of terrigenous DOM, marine organic matter produced on the shelves, and degradation products of plankton-derived organic matter in the shelf sediments. A stronger relationship between dFe and visible wavelength CDOM fluorescence than with lignin phenols suggested the presence of multiple terrigenous ligands, such as aromatic tannins. The aromatic nature of these terrigenous ligands was indicated by a strong relationship between dFe and the absorption coefficient at 254 nm. A strong negative correlation between the p-hydroxyl to vanillyl lignin phenols ratio and dissolved iron concentrations indicated recently-discharged terrigenous DOM (tDOM) was an important source of iron-binding ligands. Given the strong relationships of marine and terrigenous DOM with dissolved iron, iron-binding functional groups appear to occur in diverse molecules of multiple sources. Examples of such iron-binding functional groups included catechols and carboxylates found in lignins and tannins of terrigenous origins and carboxyl-rich alicyclic molecules (CRAM) of terrigenous and marine origins. The observed dFe distributions in the Arctic Ocean could not be explained by the presence of a single ligand type, but rather by a potpourri of ligand molecules of varying concentrations and binding strengths. This molecular diversity of ligands and associated binding strengths ultimately controls the distribution and transport of dFe in the Arctic Ocean and beyond.

测定了拉普捷夫海和北极主要海盆中的溶解木质素酚，发色溶解有机物（DOM）和原位荧光，并将其与溶解铁（dFe）分布进行比较，以阐明其来源，分子特征和分布北冰洋中的铁结合配体。在跨极漂移区（TPD）中，dFe的浓度与木质素酚的浓度以及DOM组成和来源的多个光学代理呈正相关。dFe与可见光和紫外波长荧光DOM之间有很强的关系，表明维管植物和藻类DOM构成了dFe-配体库。这些观察结果与以前的研究一致，表明dFe与腐殖性陆生和海洋有机配体有关。铁结合配体的主要来源似乎是陆源DOM的河流排放，陆架上产生的海洋有机物以及陆架沉积物中浮游生物来源的有机物的降解产物。dFe和可见光波长CDOM荧光之间的关系比木质素酚更强，这表明存在多个陆源性配体，例如芳香单宁。dFe与254 nm处的吸收系数之间的密切关系表明了这些陆源配体的芳香性质。对羟基与香草基木质素酚的比率与溶解的铁浓度之间存在很强的负相关性，表明最近释放的陆源DOM（tDOM）是铁结合配体的重要来源。鉴于海洋和陆源DOM与溶解的铁之间的密切关系，铁结合的官能团似乎出现在多种来源的不同分子中。这种铁结合官能团的实例包括在陆源来源的木质素和单宁以及陆源和海洋来源的富含羧基的脂环族分子（CRAM）中发现的儿茶酚和羧酸盐。在北冰洋观察到的dFe分布不能通过单一配体类型的存在来解释，而不能通过浓度和结合强度不同的配体分子的混杂来解释。配体的这种分子多样性和相关的结合强度最终控制了dFe在北冰洋及其以外地区的分布和运输。这种铁结合官能团的实例包括在陆源来源的木质素和单宁以及陆源和海洋来源的富含羧基的脂环族分子（CRAM）中发现的儿茶酚和羧酸盐。在北冰洋观察到的dFe分布不能通过单一配体类型的存在来解释，而不能通过浓度和结合强度不同的配体分子的混杂来解释。配体的这种分子多样性和相关的结合强度最终控制了dFe在北冰洋及其以外地区的分布和运输。这种铁结合官能团的实例包括在陆源来源的木质素和单宁以及陆源和海洋来源的富含羧基的脂环族分子（CRAM）中发现的儿茶酚和羧酸盐。在北冰洋观察到的dFe分布不能通过单一配体类型的存在来解释，而不能通过浓度和结合强度不同的配体分子的混杂来解释。配体的这种分子多样性和相关的结合强度最终控制了dFe在北冰洋及其以外地区的分布和运输。在北冰洋观察到的dFe分布不能通过单一配体类型的存在来解释，而不能通过浓度和结合强度不同的配体分子的混杂来解释。配体的这种分子多样性和相关的结合强度最终控制了dFe在北冰洋及其以外地区的分布和运输。在北冰洋观察到的dFe分布不能通过单一配体类型的存在来解释，而不能通过浓度和结合强度不同的配体分子的混杂来解释。配体的这种分子多样性和相关的结合强度最终控制了dFe在北冰洋及其以外地区的分布和运输。