Collaborative Research: GEOTRACES Arctic Section: Sampling and Analysis of Atmospheric Deposition

在这个项目中，参加2015年美国GEOTRACES北冰洋考察的一组研究人员将研究海水、海冰和海洋空气中多种微量元素的分布。了解它们在北极的位置以及它们如何移动非常重要，因为有些微量元素对生命至关重要，有些是已知的生物毒素，还有一些很重要，因为它们可以用作海洋中各种物理、化学和生物过程的示踪剂。与国际地理追踪计划中的其他多国倡议一样，美国北极探险的目标是确定控制海洋中关键微量元素和同位素分布的过程和量化通量，并确定这些分布对不断变化的环境条件的敏感性。这个由海洋微量元素专家组成的多机构团队将重点关注气溶胶、降水和海冰融水在微量元素循环中的重要性。这项工作的成果将通过公共教育举措进行传播，例如网络通信和向公众（包括阿拉斯加的土著居民）进行宣传。该项目还将为研究生和本科生提供生物学和化学方面的培训。大气沉降是天然气溶胶和污染物进入海洋的重要途径和传输机制。与其他地区相比，北极的大气沉积率较低，降水中的气溶胶和溶解的化学物质可能会直接沉积到海面，或者（极地地区特有的）沉积到海冰上。考虑到该地区独特的生物地球化学过程及其对全球气候变化的快速变化，量化北极不同流域（海洋、海冰和融水池）中微量元素和同位素当前大气沉积情况对于我们预测其分布随时间变化的能力至关重要。在这项研究中，将收集气溶胶、降水和融水样本并分析微量元素和同位素，以评估自然和人为气溶胶对海洋表面和海冰化学的影响。通过该项目，从北极收集的大气样本也将分发给更广泛的科学界。

In this project, a group of investigators participating in the 2015 U.S. GEOTRACES Arctic Ocean expedition will study the distribution of a variety of trace elements in seawater, sea ice, and marine air. It is important to understand where they are and how they move in the Arctic because some trace elements are essential to life, others are known biological toxins, and still others are important because they can be used as tracers of a variety of physical, chemical, and biological processes in the sea. In common with other multinational initiatives in the International GEOTRACES Program, the goals of the U.S. Arctic expedition are to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions. This multi-institutional team of ocean trace element experts will focus its attention on the importance of aerosol, precipitation, and sea ice melt water in trace element cycling. Results from this work will be disseminated through public educational initiatives, such as web communications and outreach to members of the public, including indigenous populations in Alaska. The project will also provide training for graduate and undergraduate students in biology and chemistry. Atmospheric deposition is an important pathway and transport mechanism of both natural aerosols and contaminants to the ocean. Relative to other regions, atmospheric deposition rates in the Arctic are low and aerosols and dissolved chemicals in precipitation may be deposited directly to the sea surface or, unique to polar regions, onto sea ice. Given the unique biogeochemical processes of the region and its rapid changes in response to global climate change, quantifying the current atmospheric deposition of trace elements and isotopes to differing catchments (ocean, sea ice, and melt ponds) in the Arctic is critical to our ability to predict how their distribution may evolve over time. In this study, aerosol, precipitation, and melt water samples will be collected and analyzed for trace elements and isotopes in order to evaluate the impacts on the surface ocean and sea ice chemistry from natural and anthropogenic aerosols. Through this project, collected atmospheric samples from the Arctic will also be made available for distribution to the broader scientific community.