Sea ice physical properties and their application to ocean-atmosphere interaction

海冰物理特性及其在海洋-大气相互作用中的应用

• 批准号: RGPIN-2015-03842
• 负责人: Galley, Ryan
• 金额: $ 1.46万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=708065
• 关键词: Sea; ice; physical; properties; their

The long-standing concept that ocean-atmosphere interaction cannot occur through sea ice is invalid. We now understand sea ice provides a variably effective conduit for ocean-atmosphere exchange, particularly for CO2. It is now thought that sea ice (depending on its temperature) may produce CO2 as it forms or grows, which may be trapped within the ice and eventually exported to the deep ocean. These interactions are modulated by the shape, location and connectivity of its liquid and gas inclusions, the intrinsic properties of which are controlled by a vertical temperature gradient within the ice and depend also on the sea ice type and age. We aim to characterize the size, shape, location and connectedness of liquid and gas inclusions in sea ice and changes therein from formation to melting. These results are imperative in determining how much atmospheric CO2 may be sequestered in polar oceans over an annual cycle both through, and as a result of, sea ice processes. A significant obstacle to this work is the traditional methodology for sea ice sampling. That is, the vertical removal of a sea ice core from a larger volume and its subsequent storage at -20°C. Once a sea ice core sample is pulled upward and out of sea ice floating in the ocean, it's no longer connecting the ocean and atmosphere, and the vertical temperature gradient that controls much of the physics we're interested in is irreparably affected. This is especially relevant to the bottom portion of the sea ice bathed in ocean water through liquid channels extending upward into it. A useful analogy is a sponge removed from a sink of water. Removing the sponge from the sink and slicing it up it to see how much water it contained may not yield realistic results. The overarching goal of this program is methodological development. The limitations of sea ice coring and sample storage have been known for a long time; my students and I will endeavour to employ existing imaging techniques long used in other areas, and develop new state-of-the-art methods for the non-invasive measurement of the shape, location and type of sea ice inclusions. We would like to quantify how much liquid and air are in the proverbial sponge when it is floating in the sink, while it is floating in the sink. This work will greatly expand current knowledge on how sea ice affects the biogeochemical processes and CO2 fluxes between the ocean and atmosphere in polar seas. Results of this work will include a long-sought observationally-derived library of permeability data for sea ice, partitioned relatively by phase, (including liquid brine, gases and solid salts) for a variety of sea ice stages of development as a function of naturally wide ranging physical conditions. These results are vitally important for verification of existing theoretical approximations and modeling of sea ice brine retention, brine drainage and greenhouse gas transport through sea ice to the ocean below.

长期存在的认为海洋与大气相互作用不能通过海冰发生的概念是无效的，我们现在知道海冰为海洋与大气交换提供了一种不同有效的渠道，特别是对于二氧化碳而言，现在人们认为海冰（取决于其温度）。 ）在形成或生长时可能会产生二氧化碳，这些二氧化碳可能被困在冰中并最终输送到深海。这些相互作用受到其液体和气体包裹体的形状、位置和连通性的调节，其固有特性受到控制。通过垂直冰内的温度梯度还取决于海冰的类型和年龄，我们的目标是表征海冰中液体和气体包裹体的大小、形状、位置和连通性，以及其中从形成到融化的变化。在每年的循环中，有多少大气二氧化碳可以通过海冰过程被封存在极地海洋中。 这项工作的一个重大障碍是海冰采样的传统方法，即从较大体积中垂直取出海冰芯，然后将海冰芯样本向上拉并储存在 -20°C 下。由于海冰漂浮在海洋中，它不再连接海洋和大气，并且控制我们感兴趣的许多物理现象的垂直温度梯度受到不可挽回的影响，这与海冰的底部尤其相关。通过向上延伸的液体通道沐浴在海水中一个有用的类比是从水槽中取出海绵并将其切成薄片以查看其含有多少水可能不会产生实际结果。 该计划的首要目标是方法论的发展，我和我的学生长期以来都知道海冰取芯和样本存储的局限性；我们将努力利用其他领域长期使用的现有成像技术，并开发新的技术。 -非侵入性测量海冰夹杂物的形状、位置和类型的最先进方法我们希望量化海绵漂浮在水槽中时的液体和空气含量。在水槽里。 这项工作将极大地扩展目前关于海冰如何影响极地海洋海洋和大气之间的生物地球化学过程和二氧化碳通量的知识。这项工作的结果将包括一个长期寻求的、相对划分的、通过观测得出的海冰渗透性数据库。根据自然范围广泛的物理条件，对各种海冰发展阶段（包括液态盐水、气体和固体盐）进行了分析，这些结果对于验证现有的理论近似值和海洋建模至关重要。冰盐水滞留、盐水排放和温室气体通过海冰输送到下面的海洋。