Collaborative Research: Defining the Atmospheric Deposition of Trace Elements Into The Arctic Ocean-Ice Ecosystem During The Year-Long MOSAiC Ice Drift.

该项目将在为期一年的探险中使用铍7(7-Be)方法，作为国际多学科漂移气候观测站的一部分，以评估气溶胶沉积的季节变化。这是对进入北冰洋/冰生态系统的微量元素(TES)的年度沉积通量进行这种全面研究的第一次现代机会。7-BE和气溶胶TE测量相结合已被证明是估计偏远海洋区域大气TES输入的有效工具，这些区域附近没有陆上采集点。在这项工作中产生的数据将可用于地面真实的气溶胶沉积模型和TES的大气输入。大气沉降是人类活动产生的痕量元素，特别是汞(Hg)进入北冰洋的主要途径，最近的文献表明，大气中铁(Fe)等生物必需的微量元素的沉积在控制北极生物生产力方面发挥了重要作用。大气气溶胶的输送和沉积是自然和污染物痕量元素(TES)向北极输送的重要机制。现有数据表明，汞、铅和硒等污染物元素在大气中的沉积可能是这些元素进入北极的主要来源，可能的来源是欧洲、俄罗斯和亚洲与化石燃料燃烧有关的人为工业或发电厂排放。大气中生物必需的微量元素(如锰、铁、钴、镍、铜、锌)的输入在控制海洋中的生物地球化学过程中起着关键作用，最近的研究表明，北极地区也可能是这样。这些投入对生态系统，甚至对人类健康都有很大影响。对这一投入的评估很困难，因为对偏远海洋区域的沉淀率的测量很少，在北极进行测量尤其令人望而生畏，因为恶劣的条件和有限的研究平台使得很难获得常规的质量控制的降水和气溶胶化学测量。这项研究将提供对气溶胶TES(总的和可溶的)的年大气沉积通量的估计，包括那些具有生物地球化学重要性的气溶胶TES以及污染物种类。还将评估不同集水区(冰、水、雪、融化池塘)之间的微量元素沉积分配的季节性演变。这项工作将涉及对7-Be清单、7-Be气溶胶活动和TES气溶胶浓度的测量。实地工作将是马赛克探险穿越北冰洋中部长达一年的冰流期间。该项目将是马赛克探险的一部分，马赛克探险是一项国际倡议，受到快速演变的北极气候系统的推动，海冰变薄，海洋和大气温度变暖，强烈的气候反馈，以及对社会的戏剧性影响。MOSAIC拥有广泛的国际支持，并已得到国际和美国机构的认可，认为该项目对于提供支持耦合模式开发所需的不断变化的北极中部系统的基础信息至关重要。提供对北冰洋相关TES大气输入的估计的能力将广泛有助于化学海洋学领域，包括了解TES对该区域的人为影响以及大气TES输入在北冰洋生态中的作用。牵头机构是该国领先的少数族裔服务大学之一，首席研究员为参与其研究活动的学生开展了一项指导计划。该团队将录制简短的讲座和视频日志，供他在未来的课程迭代中使用，以介绍重要的海洋学概念，并向他的学生第一手描述海洋船只上的生活。其他科学家将被要求接受采访，以增加视角的广度，外展将强调基础科学研究在提高我们对自然现象的理解和地球对人为压力的反应方面的作用。

This project will use a Beryllium 7 (7-Be) method in a year-long expedition as part of the international Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition to assess the seasonal variability of aerosol deposition. This is the first modern opportunity for such a comprehensive study of the yearly depositional flux of trace elements (TEs) into the Arctic ocean/ice ecosystem. The combination of 7-Be and aerosol TE measurements has been shown to be an effective tool for estimating the atmospheric input of TEs in remote ocean regions where nearby land-based collection sites do not exist. The data generated in this work will be available to allow ground-truthing of models of aerosol deposition and atmospheric input of TEs. Atmospheric deposition is the dominant pathway by which anthropogenically-derived trace elements, especially mercury (Hg), enter the Arctic Ocean, and recent literature suggests that atmospheric deposition of biologically-essential trace elements such as iron (Fe) could play a major role in controlling biological productivity in the Arctic.Atmospheric transport and deposition of aerosols is an important delivery mechanism of natural and contaminant trace elements (TEs) to the Arctic. Existing data show that atmospheric deposition of contaminant elements like Hg, Pb, and Se may be a major input of these elements to the Arctic, with likely sources being anthropogenic - industrial or power plant emissions associated with fossil fuel combustion in Europe, Russia, and Asia. The atmospheric input of biologically-essential trace elements (e.g. Mn, Fe, Co, Ni, Cu, Zn) plays a key role in controlling biogeochemical processes in the ocean, and recent work suggests this might be true in the Arctic as well. These inputs have strong implications for the ecosystem, and even human health. Assessment of this input is difficult because measurements of deposition rates in remote ocean regions are scarce, and are particularly daunting to take in the Arctic because harsh conditions and limited research platforms make it difficult to obtain quality-controlled precipitation and aerosol chemistry measurements on a routine basis. This research will provide estimates of the yearly atmospheric deposition flux of aerosol TEs (total and soluble), including those of biogeochemical importance as well as pollutant species. The seasonal evolution of partitioning of trace element deposition among the various catchments (ice, water, snow, melt ponds) will also be assessed. The work will involve measurements of 7-Be inventories, 7-Be aerosol activities, and aerosol concentrations of TEs. Field work will be during a year-long ice drift of the MOSAiC expedition through the central Arctic Ocean.This project will be a component of the MOSAiC expedition, an international initiative motivated by the rapidly evolving Arctic climate system, with thinning sea ice, warming ocean and atmosphere temperatures, strong climate feedbacks, and dramatic implications for society. MOSAiC has broad international support and has been endorsed by international and US institutions as a project that is critically needed to provide foundational information on the changing central Arctic system required to support coupled model development. The ability to provide estimates of the atmospheric input of relevant TEs to the Arctic Ocean will contribute widely to the field of chemical oceanography, including understanding anthropogenic impacts on the region and the role atmospheric input of TEs plays in Arctic Ocean ecology. The lead institution is one of the country's leading minority serving universities, and the lead researcher has undertaken a mentoring program for students involved in its research activities. The team will record short lectures and video logs that can be used in future iterations of his courses to introduce important oceanographic concepts and give his students a first-hand account of life aboard an oceanographic vessel. Other scientists will be asked to grant interviews to add to the breadth of perspectives, and the outreach will emphasize the role of basic scientific research in improving our understanding of natural phenomena and the planet's response to anthropogenic stressors.