Collaborative Research: Quantifying Seasonal and Interannual Changes in Shelf-Derived Material Inputs to the Arctic Ocean: The Arctic Radium Isotope Observing Network (ARION)

在北极圈内，迅速上升的空气和海洋温度导致海冰减少、河流流量增加、海岸侵蚀和永久冻土融化。其中许多变化正在向北冰洋周围的浅海增加营养物质和碳，特别是通过增加与陆地或大陆架上的沉积物的相互作用。重要的是，由此产生的变化并不局限于沿海海域：增加的营养物质和碳可以通过强大的表面洋流输送到北冰洋中部。因此，北冰洋化学中与气候有关的变化可能影响整个北极的初级生产，并最终影响通过北极外流到达北大西洋的营养物质的数量。该项目将通过监测镭同位素的年际和季节变化来填补一个重要的研究空白，作为来自沉积物的化学物质输入北冰洋的代用物，重点关注从大陆架海洋到北极中部的元素转移。镭同位素在海洋边界不断产生，可溶于海水。因此，镭可以作为类似来源的货架衍生材料的类似物，包括碳、营养物质和微量金属等生物上重要的元素。为了验证气候变化导致陆源溶质向北冰洋输送增加的假设，将在沿拉普捷夫海和东西伯利亚海边缘的两年一次的巡航上测量镭水平（以捕捉年际变化），并使用首个同类的原位镭同位素采样器（以捕捉季节变化）。这些取样工作将得到一个国际合作者网络的补充，该网络将提供数据，以创建一个跨越北冰洋的北极镭同位素观测网络（ARION），并将为更大的科学界服务。该项目还将与一位艺术家兼探险家合作，通过当地博物馆的展览向公众传达这项研究的重要性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Within the Arctic Circle, rapidly rising air and sea temperatures have resulted in the loss of sea ice, increased river discharge, coastal erosion, and permafrost thaw. Many of these changes are adding nutrients and carbon to the shallow seas that surround the Arctic Ocean, specifically by increasing interactions with sediments on the land or those over the continental shelf. Importantly, the resulting changes are not limited to the coastal seas: added nutrients and carbon can be transported to the central Arctic Ocean via strong surface currents. Climate-related changes in Arctic Ocean chemistry may therefore influence primary production across the Arctic, and ultimately affect the amount of nutrients reaching the North Atlantic via Arctic outflow. This project will fill an important research gap by monitoring interannual and seasonal changes in radium isotopes as proxies for chemical inputs to the Arctic Ocean that are sourced in sediments, with a focus on the transfer of elements from the shelf seas to the central Arctic.Radium isotopes are continuously produced at ocean boundaries and are soluble in seawater. Radium therefore serves as an analogue for similarly sourced shelf-derived materials, including biologically important elements such as carbon, nutrients, and trace metals. To test the hypothesis that climate change is leading to increased delivery of terrestrially-derived solutes to the Arctic Ocean, radium levels will be measured on bi-annual cruises along the Laptev and East Siberian Sea margins (to capture interannual changes) and on a first-of-its kind in situ radium isotope sampler (to capture seasonal changes). These sampling efforts will be complemented by an international network of collaborators that will contribute data to create an Arctic Radium Isotope Observing Network (ARION) that spans the Arctic Ocean and will serve the greater scientific community. The project will also partner with an artist-explorer to communicate the importance of this research to the general public through exhibitions at a local museum.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.