Observations of dissolved iron concentrations in the World Ocean: implications and constraints for ocean biogeochemical models
Observations of dissolved iron concentrations in the World Ocean: implications and constraints for ocean biogeochemical models
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世界海洋中溶解铁浓度的观测：对海洋生物地球化学模型的影响和限制
DOI：
10.5194/bgd-4-1241-2007
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
O. Braucher
中科院分区：
文献类型：
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作者：
J. K. Moore;O. Braucher
抽象的。分析全球汇编的溶解铁观测提供了深入了解铁分布的控制过程和海洋地球化学模型的一些限制。溶解铁的分布是一致的概念模型开发的Th同位素的清除，其中颗粒清除是一个两步的清除过程，主要是由胶体和小颗粒，然后聚集和去除较大的下沉颗粒。大部分溶解铁（~0.02 μm），因此可能会发生聚集和清除作用。只有与可溶性配体结合的铁（来自灰尘沉积和大陆沉积物的输入是溶解铁分布的关键驱动因素。这些观测结果为海洋地球化学模式提供了几个强有力的限制：1）北大西洋和北太平洋的深海浓度相似（~0.6-0.8 nM），而南大洋的深海溶解铁浓度要低得多（约0.3-0.4 nM）;（2）远离高尘埃沉积区的上层海洋中铁的强烈贫化，真光层以下溶解铁的清除作用显著;和3）在表面沃茨中的双峰分布，峰小于0.2 nM和在0.6-0.8 nM之间。我们比较了溶解铁观测与生物地球化学元素循环（BEC）海洋模型的输出。模型输出与现场数据基本一致（r=0.76，深度为103-502 m），但在较低的铁浓度（
Abstract. Analysis of a global compilation of dissolved iron observations provides insights into the controlling processes for iron distributions and some constraints for ocean biogeochemical models. The distribution of dissolved iron is consistent with the conceptual model developed for the scavenging of Th isotopes, whereby particle scavenging is a two-step process of scavenging mainly by colloidal and small particulates followed by aggregation and removal on larger sinking particles. Much of the dissolved iron ( ~0.02 μm) and, thus, likely subject to aggregation and scavenging removal. Only the iron bound to soluble ligands ( Inputs from dust deposition and continental sediments are key drivers of dissolved iron distributions. The observations provide several strong constraints for ocean biogeochemical models: 1) similar deep ocean concentrations in the North Atlantic and North Pacific (~0.6–0.8 nM), and much lower deep ocean dissolved iron concentrations in the Southern Ocean (~0.3–0.4 nM); 2) strong depletion of iron in the upper ocean away from the high dust deposition regions, with significant scavenging removal of dissolved iron below the euphotic zone; and 3) a bimodal distribution in surface waters with peaks less than 0.2 nM and between 0.6–0.8 nM. We compare the dissolved iron observations with output from the Biogeochemical Elemental Cycling (BEC) ocean model. The model output was in general agreement with the field data (r=0.76, for depths 103–502 m), but at lower iron concentrations (