在北大西洋溶解铁源的量化
11] Department of Earth and Ocean Sciences, University of South Carolina, Columbia, South Carolina 29208, USA [2] Institute of Geochemistry and Petrology, Eidgenössische Technische Hochschule Zürich, NW D81.4, Clausiusstrasse 25, 8092 Zürich, Switzerland.
Nature
|July 11, 2014
概括
撒哈拉沙漠的尘埃是北大西洋中溶解铁的主要来源,对海洋浮游生物和海洋碳循环至关重要. 了解这些铁源是预测气候相互作用的关键.
科学领域:
- 海洋学 海洋学 海洋学
- 地质化学 地质化学
- 海洋生物地质化学海洋生物地质化学
背景情况:
- 溶解的铁是海洋浮游生物的一个必不可少的微量营养素.
- 铁的可用性控制了海洋的初级生产力和碳循环.
- 海洋铁的来源 (尘埃,热水喷口,沉积物) 量化得很差.
研究的目的:
- 为了确定不同铁源对北大西洋溶解铁池的相对贡献.
- 为了利用铁稳定同位素比率 (δ(56) Fe) 作为铁源的标记物.
主要方法:
- 在北大西洋的溶解稳定铁同位素比率 (δ(56) Fe) 和铁度 ([Fe]) 的高分辨率截图.
- 分析 δ(56) Fe 的特征,以区分铁的来源.
- 基于同位素混合模型计算源贡献.
主要成果:
- 撒哈拉沙漠尘埃气溶是主要的溶解铁来源 (71-87%).
- 沉积物释放的贡献为10-19% (非减少性) 和1-4% (减少性).
- 水热喷气孔贡献2-6%并提供同位素轻铁.
结论:
- 撒哈拉沙漠的尘埃是研究北大西洋地区溶解铁供应的主要驱动因素.
- 水热喷口释放出同位素轻铁,可以行驶很长距离,影响生产力.
- 铁源的时间变化可以影响海洋碳循环和气候相互作用.
相关概念视频
Precipitation and Co-precipitation
5.7K
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
5.7K
Microbes and Other Elemental Cycles
66
Microbial activity plays a pivotal role in the biogeochemical cycling of iron and manganese, especially at the redox gradients characteristic of stratified aquatic environments. These cycles are driven by microbial transformations between oxidized and reduced forms of the metals, allowing organisms to exploit them for metabolic energy and structural purposes.Iron Cycling Across Redox GradientsIn neutral, oxygen-rich surface waters, iron is predominantly found in its oxidized, insoluble ferric...
66
Acid Mine Drainage
61
Mining activities that disturb sulfide-rich rocks, particularly those containing pyrite (FeS₂), initiate a cascade of geochemical and microbiological processes with serious environmental implications. When exposed to air and water, pyrite undergoes oxidation, releasing sulfate, ultimately forming sulfuric acid and mobilizing heavy metals into surrounding water systems. This phenomenon, known as acid mine drainage (AMD), results in low pH waters laden with toxic elements that threaten...
61


