Collaborative Research: Impact of Atmospheric Deposition on the Distribution and Speciation of Trace Elements in the Upper Ocean - Focus on Iron in the Sargasso Sea

合作研究：大气沉降对上层海洋微量元素分布和形态的影响 - 关注马尾藻海中的铁

• 批准号: 0926780
• 负责人: Peter Sedwick
• 金额: --
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0926780&HistoricalAwards=false
• 关键词: Collaborative; Research; Impact; Atmospheric; Deposition; Collaborative; Research; Impact; Atmospheric; Deposition

Recent studies in the Sargasso Sea (BATS region) have revealed a large, seasonal-scale change in the dissolved iron (Fe) concentration of the surface waters where concentrations decreased from ~1-2 nM in summer 2003, when aerosol Fe concentrations were high, to ~0.1-0.2 nM in spring 2004, when aerosol Fe concentrations were low. These changes were interpreted as the result of the seasonal dust input into the highly-stratified, oligotrophic surface waters during the summer, followed by the removal of this aeolian iron due to the convective mixing, biological uptake and particle scavenging during the winter-early spring. Researchers from the Bermuda Biological Station for Research, the University of Delaware and Woods Hole Oceanographic Institute have devised a simple model that implies that aeolian input of dissolved Fe into the surface ocean does not scale with total aerosol Fe concentrations. To test this hypothesis, the scientists will use the Sargasso Sea as a natural laboratory to carry out the following objectives: (1) achieve a quantitative understanding of the impact of mineral aerosol deposition (dry and wet) on the concentration and speciation of Fe in surface waters of the Sargasso Sea; (2) test the new model for aerosol Fe solubility that have been developed for the Sargasso Sea, and thus evaluate the potential for application of this model at the global scale; and (3) evaluate the need for an autonomous, buoy-mounted aerosol sampler for quantifying the concentration and solubility of aerosol iron over the open ocean. To attain these goals, both time-series observations and intensive process studies will be done. The work will include shipboard water-column sampling, atmospheric sampling at the Tudor Hill tower on Bermuda, the use of an autonomous aerosol sampler on the Bermuda Testbed Mooring, and subsequent analyses of the concentration and speciation of Fe and other trace metals in seawater, aerosol, and rainwater samples. As regards broader impacts, this study will provide needed data to improve predictive capabilities of biogeochemical-ecosystem models. In addition, this project will document the utility of an autonomous, buoy-mounted aerosol sampling systems linking atmospheric and oceanographic processes for environmental monitoring and research in marine geochemistry and biogeochemistry. The goals of this research are compatible with the focus of the SOLAS and GEOTRACES programs. One graduate student and one undergraduate student (funded as part of the REU program) from the University of Delaware will be trained as part of this project.

萨尔加索海（蝙蝠区）的最新研究表明，地表水的溶解铁（Fe）浓度发生了较大的季节性变化，该浓度从2003年夏季的〜1-2 nm降低，当时气雾剂Fe浓度很高，到2004年春季的〜0.1-0.2 nm，当时气溶胶浓度低。这些变化被解释为夏季中季节性的粉尘输入到高度分层的，贫营养的地表水中，然后由于对流混合，生物学吸收和颗粒在冬季春季清除，因此去除了这种Aeolian铁。特拉华大学和伍兹洞海洋学研究所的研究人员研究人员设计了一个简单的模型，这意味着风化的溶解Fe对地面海洋的溶解Fe的输入不会随着气雾剂Fe浓度而扩展。 为了检验这一假设，科学家将使用Sargasso Sea作为天然实验室来执行以下目标：（1）对矿物质气溶胶沉积（干和湿）对FE在Sargasso Sea地表水中的浓度和物种形成的影响进行定量理解； （2）测试已为Sargasso Sea开发的气溶胶Fe溶解度的新模型，从而评估了该模型在全球规模上应用的潜力； （3）评估对浮标的自主气溶胶采样器的需求，以量化气溶胶铁在开阔的海洋上的浓度和溶解度。为了实现这些目标，将完成时间序列的观察和密集的过程研究。 这项工作将包括船上的水柱采样，百慕大的都铎山塔的大气采样，在百慕大测试床系泊台上使用自主气溶胶采样器，以及随后在海水，气溶胶和雨水样品中对FE和其他微量金属的浓度和其他微量金属的浓度分析。关于广泛的影响，本研究将提供所需的数据，以提高生物地球化学模型的预测能力。 此外，该项目还将记录一个自主，浮标的气溶胶采样系统的实用性，该系统将大气和海洋学过程连接起来，以进行海洋地球化学和生物地球化学的环境监测和研究。 这项研究的目标与Solas和Geotraces计划的重点兼容。 一名研究生和一名本科生（作为REU计划的一部分资助）将作为该项目的一部分进行培训。