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: 2141358
• 负责人: David Ho
• 金额: $ 32.12万
• 依托单位: University of Hawaii
• 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=2141358&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：北极海覆盖了北极，其表面每年冬天都会用一层海冰冻结，厚1-3米。当海水冻结时，冰会排出盐，使冰层主要由淡水组成。因此，当海冰在夏季融化时，它会产生一层薄薄的淡水，将漂浮在其下面的盐水上。传统的海洋学测量很少测量这一新层，因为船只通常从大约5 m的深度收集数据。然而，这些淡水镜头可能会发挥关键作用，影响气体的气氛 - 二氧化碳，包括二氧化碳，负责全球变暖的主要气体以及北极海夏季海冰覆盖范围的几乎一半。北极海洋被认为吸收了大约10％的人类二氧化碳排放。尽管如此，这个数字还是高度不确定的，部分是由于表面上的观察值稀缺。该项目旨在通过在研究容器和称为Wave Glider的自主表面平台上取样Beaufort Sea的淡水层来解决这种不确定性的来源。我们将比较新鲜层的化学反应与其下面的盐水，并使用这些数据纠正二氧化碳摄取量的估计，以实现以前未测量的北极影响，从而经历了季节性海冰融化，这是德克萨斯州大小的2.5倍的区域。对海洋碳摄取的更好估计有助于我们更好地了解全球碳预算，并监控减缓气候变化的努力。项目科学家将训练博士学位。 URI METCALF Institute的学生和与科学传播专家合作，通过网络研讨会系列与北极海洋科学的新闻工作者和公众观众一起工作。第2部分：北极海洋占据了人类发出的大约10％的二氧化碳，这有助于减少气候变化的影响。但是，由于观察次数及其收集方式，我们对北极海洋碳汇的了解尚不确定。北极的变暖比地球上其他任何地方都要快，从而导致海冰覆盖率发生了巨大变化。撤退的海冰留下的淡水层通常持续1至5周。它的二氧化碳水平与仅深几米的水水平不同，由于其摄入水的位置，船只通常已经进行了采样。由于海洋对碳的吸收取决于地表的二氧化碳水平，因此融化水与通常由船只采样的差异需要对这些基于船舶的测量结果进行校正。这种纠正将影响覆盖0.35至175万km2的季节性无冰北极海洋区域的碳水槽（比得克萨斯州大的2.5倍）。该项目将与由NASA物理海洋学计划资助的科学家合作，在一个名为Sale Ice Edge（Sassie）的盐度和分层的项目中。Sassie将包括船舶和称为Wave Gliders的自动式地面车辆的测量。 Classsie将在船上的融合层中和下方进行碳测量，并从其中一个波滑翔机进行相同的操作。从这些测量值中，Classsie将确定盐度和二氧化碳水平之间具有融合水输入的海洋之间的关系。利用盐度与二氧化碳水平之间的经验关系，将提出融化层的校正，并与来自计算机模型的融水层统计数据结合使用，以生成北极海洋二氧化碳水平的修改图。最后，将使用修改后的地图创建对北极海洋水槽的修订估计。对北极海洋碳汇的精炼估计值将有助于限制全球碳预算，这对于监测气候变化至关重要。该项目将培训博士学位。学生。 Classsie还将与URI的Metcalf Institute合作，开发一个由四部分组成的网络研讨会系列，以吸引记者，公共受众和北极海洋科学的兴趣研究人员。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准来通过评估来通过评估来支持的。