Collaborative Research: Carbon Levels at the Arctic Salinity-Stratified Sea Ice Edge (CLASSSIE)

合作研究：北极盐度分层海冰边缘的碳水平（CLASSSIE）

• 批准号: 2141278
• 负责人: Jaime Palter
• 金额: $ 5.14万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-15 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2141278&HistoricalAwards=false
• 关键词: Collaborative; Research; Carbon; Levels; Arctic

Part 1:The Arctic Ocean covers the North Pole and its surface is frozen each winter with a layer of sea ice that can be 1-3 meters thick. When seawater freezes, the ice expels the salt so that the layer of ice is composed mostly of freshwater. Therefore, when the sea ice melts in summer, it creates a thin layer of freshwater that floats on the saltier seawater beneath it. Traditional oceanographic measurements rarely measure this fresh layer because ships typically collect data from a depth of about 5 m. Yet, these freshwater lenses may play a key role influencing the atmosphere-ocean exchange of gases, including carbon dioxide, the principal gas responsible for global warming and the loss of nearly half of the summertime sea ice coverage of the Arctic Ocean. The Arctic Ocean is thought to absorb about 10% of the human emissions of carbon dioxide. Still, this number is highly uncertain, owing partly to the scarcity of observations at the very surface. This project aims to address that source of uncertainty by sampling the freshwater layer in the Beaufort Sea, both aboard a Research Vessel and on an autonomous surface platform called Wave Glider. We will compare the chemistry of the fresh layer to the saltier water just beneath it and use these data to correct estimates of carbon dioxide uptake for this previously-unmeasured impact across the entire portion of the Arctic that experiences seasonal sea ice melt, an area up to 2.5 times the size of Texas. Better estimates of ocean carbon uptake help us better understand the global carbon budget and monitor efforts to slow climate change. Project scientists will train a Ph.D. student and work with science communication experts at URI’s Metcalf Institute to engage journalists and public audiences in Arctic Ocean science through a webinar series.Part 2:The Arctic Ocean takes up about 10% of the carbon dioxide that humans emit, which helps diminish the effects of climate change. However, our knowledge about the Arctic Ocean carbon sink is uncertain due to the number of observations and how they are collected. The Arctic is warming faster than anywhere else on Earth, leading to dramatic changes in sea ice cover. The fresher meltwater layer left behind by the retreating sea ice typically lasts for 1 to 5 weeks. It has different carbon dioxide levels than the water just a few meters deeper, where ships generally have sampled due to the locations of their water intakes. Because the uptake of carbon by the ocean is determined by the carbon dioxide levels right at the surface, this difference between the meltwater and what is typically sampled by ships requires a correction to these ship-based measurements. This correction will affect the carbon sink over an area of the seasonally ice-free Arctic Ocean covering 0.35 to 1.75 million km2 (an area up to 2.5 times larger than Texas).Carbon Levels at the Arctic Salinity–Stratified Sea Ice Edge (CLASSSIE) is a project to measure key carbon system parameters in the marginal ice zone of the Beaufort Sea. The project will collaborate with scientists funded by the NASA Physical Oceanography program in a project called Salinity and Stratification at the Sea Ice Edge (SASSIE). SASSIE will include measurements from a ship and autonomous surface vehicles called Wave Gliders. CLASSSIE will make carbon measurements in and under the meltwater layer from the ship and do the same from one of the Wave Gliders. From these measurements, CLASSSIE will determine a relationship between salinity and carbon dioxide levels for an ocean with meltwater input. Using that empirical relationship between salinity and carbon dioxide levels, a correction in the meltwater layer will be proposed and combined with meltwater layer statistics from a computer model to produce a modified map of Arctic Ocean carbon dioxide levels. Finally, a revised estimate of the Arctic Ocean carbon sink will be created with the modified map. Refining estimates of the Arctic Ocean carbon sink will help constrain the global carbon budget, which is crucial to monitoring climate change mitigation. The project will train a Ph.D. student. CLASSSIE will also work with the Metcalf Institute at URI to develop a four-part webinar series to engage journalists, public audiences, and interested researchers in Arctic Ocean science.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.

第1部分：北冰洋覆盖北极，每年冬天其表面都会结冰，形成一层厚达1-3米的海冰。当海水结冰时，冰会排出盐分，从而形成冰层。因此，当夏季海冰融化时，会形成一层薄薄的淡水，漂浮在其下方较咸的海水上，因为船舶通常从约 5 m 的深度收集数据。然而，这些淡水透镜体可能在影响大气-海洋气体交换方面发挥着关键作用，其中二氧化碳是导致全球变暖和北冰洋夏季海冰覆盖面积减少近一半的主要气体。吸收约 10% 的人类二氧化碳排放量，但这个数字高度不确定，部分原因是缺乏对地表的观测。该项目旨在通过对淡水层进行采样来解决这一不确定性来源。波弗特海，两人都在一艘研究船上在一个名为“波浪滑翔机”的自主表面平台上，我们将比较新鲜层与其下方咸水的化学成分，并利用这些数据来纠正对整个北极地区先前未测量的影响的二氧化碳吸收量的估计。经历季节性海冰融化的区域面积达到德克萨斯州的 2.5 倍，更好地估计海洋碳吸收量有助于我们更好地了解全球碳预算并监测减缓气候变化的努力。并与科学传播专家合作URI 的梅特卡夫研究所通过网络研讨会系列吸引记者和公众参与北冰洋科学。第 2 部分：北冰洋吸收了人类排放的约 10% 的二氧化碳，这有助于减少气候变化的影响。由于观测数量和收集方式，北极的变暖速度比地球上其他任何地方都快，导致海洋退缩留下的更新鲜的融水层发生了巨大变化。冰通常持续1 到 5 周，其二氧化碳含量与仅几米深的水不同，船舶通常根据其取水位置进行采样，因为海洋吸收的碳是由二氧化碳含量决定的。在海面，融水与通常由船舶采样的数据之间的差异需要对这些基于船舶的测量进行校正，该校正将影响覆盖范围为 0.35 至 1.75 的季节性无冰北冰洋区域的碳汇。万平方公里（面积达德克萨斯州的 2.5 倍）。北极盐度分层海冰边缘的碳水平 (CLASSSIE) 是一个测量波弗特海边缘冰区关键碳系统参数的项目。该项目将与美国合作。由美国宇航局物理海洋学项目资助的一个名为“海冰边缘盐度和分层”（SASSIE）的项目将包括来自一艘名为“波浪滑翔机”的自主水面飞行器的测量。将从船上进行融水层内部和下方的碳测量，并通过其中一台波浪滑翔机进行相同的测量，CLASSSIE 将利用该经验关系确定具有融水输入的海洋的盐度和二氧化碳水平之间的关系。在盐度和二氧化碳水平之间，将提出对融水层的修正，并与计算机模型的融水层统计数据相结合，以生成北冰洋二氧化碳水平的修改图，最后，将对北冰洋碳汇进行修订的估计。被创建为改进的北冰洋碳汇估计将有助于限制全球碳预算，这对于监测气候变化缓解至关重要。该项目还将与 URI 的梅特卡夫研究所合作培训一名博士生。开发一个由四部分组成的网络研讨会系列，吸引记者、公众观众和对北冰洋科学感兴趣的研究人员。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。