Hawaii Aerosol Time-Series (HATS):Quantifying Marine Dust Deposition and Composition in an Oligotrophic Gyre

夏威夷气溶胶时间序列 (HATS)：量化寡营养环流中的海洋灰尘沉积和成分

• 批准号: 1949660
• 负责人: Clifton Buck
• 金额: $ 107.41万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1949660&HistoricalAwards=false
• 关键词: Hawaii; Aerosol; Time; Series; HATS

The chemistry of the ocean can be changed by the introduction and removal of elements, including trace elements which are present at low concentrations. In some cases, these elements are known to be vital to biological processes and ocean food webs. Near the shore, rivers are a large source for material from land to the ocean. Beyond the reach of rivers, and for most of the oceans, material blown from land through the air is the largest source of trace elements to surface waters. This material enters the oceans dissolved in rain or by settling of dust particles. Understanding atmospheric sources of trace elements to the oceans is thus important to understanding both global chemical cycles and patterns of biological production. This project will sample the atmosphere and the surface ocean near Hawaii over two years to gain a deeper understanding of the sources and fates of trace metals in the ocean. The study will examine how particles from the atmosphere interact with the surrounding water as they sink through the ocean. The project will contribute to global synthesis and modeling efforts. It will directly support graduate and undergraduate students. Results of the project and their relevance will be communicated to the public through campus open house events and a public lecture series.The processes that supply and remove trace elements in the ocean are ongoing areas of research. An important focus is on understanding the sources and fate of aerosol trace elements deposited to the ocean as this represents a major source of micronutrients and contaminants into the open ocean. Field observations of wet and dry atmospheric inputs are limited in number, and few methods are available to transform readily measured aerosol trace element concentrations into deposition fluxes. Thus, atmospheric fluxes of trace elements to most ocean regions remain poorly constrained and their impact on ocean biochemical cycles, including the marine carbon cycle, are uncertain. Directly quantifying atmospheric fluxes of key trace elements to the ocean and identifying their fates and chemical transformations after deposition are critical areas of continued investigation and are included, for example, as a core component of the GEOTRACES program. Similarly, aerosol fractional solubility and the flux of bioavailable trace elements is not well understood. There is a corresponding need to test and improve estimates of total dust deposition fluxes alongside simultaneous observations of particle composition in the open ocean. This project will address these needs through a two-year land-based sampling effort and six seasonal cruises aimed at three tasks. (1) Use the deposition flux of beryllium-7 measured from aerosols, precipitation, and the upper ocean inventory to directly estimate dust and aerosol trace element fluxes to the Hawaii Ocean Time-series Station Aloha, a representative and remote oligotrophic site. This region is characterized by a predictable seasonal variability in dust concentrations and precipitation and is an exceptionally applicable region for testing the limits of dust deposition techniques by observing seasonal variability in ocean-atmosphere coupling over a multi-year cycle. (2) Explore the extent to which seasonal variations in aerosol trace element flux to the surface of the North Pacific, and mineralogy of that input drive variability in the composition and inventories of marine particles. (3) Investigate the extent to which the fractional solubility of aerosol trace elements collected over the North Pacific shows temporal variability and calculate flux rates of soluble aerosol trace elements. The study will advance understanding of dust and soluble aerosol trace element flux from the atmosphere to the ocean and link that flux to upper ocean particle inventory, mineralogy, and chemical composition.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

可以通过引入和去除元件（包括存在低浓度的痕量元素）来改变海洋的化学。在某些情况下，这些元素对于生物过程和海洋食品网至关重要。在海岸附近，河流是从陆地到海洋的材料的重要来源。除了河流范围之外，对于大多数海洋，从空气中吹出的材料是地表水的最大痕量元素来源。该材料进入溶解在雨中或通过尘埃颗粒沉降的海洋。因此，了解海洋痕量元素的大气来源对于理解全球化学周期和生物生产的模式很重要。该项目将在夏威夷附近的大气和地面海洋中进行两年的气氛，以更深入地了解海洋中痕量金属的源头。该研究将检查来自大气中的颗粒在下沉海洋时与周围水的相互作用。该项目将有助于全球合成和建模工作。它将直接支持毕业生和本科生。该项目及其相关性的结果将通过校园开放日活动和公开演讲系列传达给公众。供应和删除海洋中的微量元素的过程正在进行中。一个重要的重点是理解沉积在海洋的气溶胶痕量元件的来源和命运，因为这代表了开放海洋中的微量营养素和污染物的主要来源。潮湿和干大气输入的现场观测数量有限，很少有可用的方法可以将容易测量的气溶胶痕量元素浓度转化为沉积通量。因此，大多数海洋区域的痕量元素的大气通量仍然受到限制，它们对包括海洋碳循环在内的海洋生化周期的影响尚不确定。直接量化对海洋关键痕量元素的大气通量，并在沉积后识别其命运和化学转化是继续研究的关键领域，例如，例如，作为Geotraces计划的核心组成部分。同样，气溶胶分数溶解度和生物利用痕量元素的通量尚不清楚。有相应的需要测试和改善总尘埃沉积通量以及对露天海洋中粒子组成的同时观察的估计。该项目将通过两年的土地抽样工作和六次针对三个任务的季节性巡游来满足这些需求。 （1）使用从气溶胶，降水和上大洋库存测得的铍7的沉积通量直接估算灰尘和气溶胶痕量元件通量到夏威夷海洋时间系列序列站Aloha，Aloha是代表性和远程少亲子性地点。该区域的特征是尘埃浓度和降水的可预测季节性变异性，是一个非常适用的区域，可通过观察多年级的海洋 - 大气耦合中的季节性变异性来测试灰尘沉积技术的极限。 （2）探索气溶胶痕量元素通量到北太平洋表面的季节性变化的程度，以及该输入的矿物学驱动驱动器的矿物学变异性驱动因素和海洋颗粒的库存中的变异性。 （3）研究在北太平洋收集的气溶胶痕量元件的分数溶解度显示出时间变化的程度，并计算可溶性气溶胶痕量元件的通量速率。该研究将使对灰尘和可溶性气溶胶痕量元件通量从大气到海洋的了解，并将磁通量与上海颗粒库存，矿物学和化学成分联系起来。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准来通过评估来支持的。