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，气温和海洋温度的迅速上升导致海冰消失、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层洋流输送到北冰洋中部。因此，与气候有关的北冰洋化学变化可能会影响整个北冰洋的初级生产，并最终影响通过北极外流进入北大西洋的养分量。该项目将填补一个重要的研究空白，办法是监测作为北冰洋化学输入的替代物质--沉积物中的元素--的年际和季节变化，重点是元素从大陆架海向北冰洋中部的转移。因此，镭作为类似来源的陆架衍生材料的类似物，包括生物上重要的元素，如碳、营养物质和痕量金属。为了检验气候变化正在导致向北冰洋输送更多陆源溶质的假设，将在拉普特夫和东西伯利亚海缘每两年一次的巡航上测量镭水平(以捕捉年际变化)，并在第一个此类原位镭同位素采样器上测量镭水平(以捕捉季节变化)。这些抽样工作将得到一个国际合作者网络的补充，该网络将贡献数据，创建一个横跨北冰洋的北极镭同位素观测网络，并将服务于更大的科学界。该项目还将与一位艺术家兼探险家合作，通过在当地博物馆的展览向公众宣传这项研究的重要性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.