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Fragmentation and melt of Arctic sea ice

北极海冰的破碎和融化

基本信息

批准号：
NE/V011693/1
负责人：
Daniel Feltham
金额：
$ 63.85万
依托单位：
University of Reading
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2022
资助国家：
英国
起止时间：
2022 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FV011693%2F1
关键词：
Fragmentation melt Arctic sea ice

项目摘要

Arctic sea ice is an important agent, and indicator, of climate change; the rapid decline of sea ice in past decades has been a wake-up call to scientists, policy-makers, and the general public. This retreat of the sea ice has led to growth of trans-Arctic shipping and plans to extract minerals and fossil fuels from the ocean floor. The latest assessment of the Intergovernmental Panel on Climate Change (IPCC) concluded that it was likely that the Arctic would become reliably ice-free by 2050 assuming greenhouse gas emissions continue to increase. However, the climate simulations used by the IPCC often fail to realistically capture large scale properties of the Arctic sea ice, such as the extent, variability and recent trends. Therefore, there is a need to improve simulations of Arctic sea ice to provide better understanding of the recent observed changes and credible projections of the future to help assess risks and opportunities and inform important policy decisions about adaptation and mitigation.Observations of the Arctic have improved in recent years: new satellites are measuring sea ice thickness and topography from space, and substantial recent and planned field programmes are contributing to our knowledge of the in situ processes controlling the evolution of the ice cover. These observations reveal not only that the extent and thickness of the Arctic ice cover is reducing in all seasons, but also show us how the ice is decreasing. In particular, recent observations demonstrate how surface melt ponds weaken the ice, fragmenting it into many floes. No operational environmental or climate model of sea ice evolution takes into account the processes of ice fragmentation or the impact of having a range of different sea ice floe sizes. Sea ice floe size affects lateral melting, air to ocean momentum transfer, rheology, and wave-ice interaction. Idealised model studies demonstrate that accounting for floe fragmentation has a leading order impact on the spatial distribution of sea ice and decreases its overall extent and volume. Because existing climate models do not contain this physics, their utility for understanding and predicting variability and change in the Arctic is compromised. This leads to impairment of climate model accuracy at lower latitudes also, due to errors in meridional atmospheric and oceanic circulations, as well as ice export from the Arctic. This proposal will determine the role of sea ice fragmentation in the accelerated retreat of Arctic sea ice. Using a combination of new and emerging observations, new theory and process modelling, we will build fundamental understanding of sea ice fragmentation. We will a) develop a high fidelity, high resolution model of sea ice thermodynamic and mechanical evolution and use this, and observations, to explore sea ice fragmentation, b) build parameterisations of fragmentation processes, including the first model of fragmentation by melt, and incorporate these into the sea ice component of climate and weather models, and c) use ice-ocean and fully coupled climate models to identify the contribution of fragmentation to: rapid ice loss over past decades, projections of ice loss in the coming decades, and creating skill for operational ice forecasts now.In addition to the scientific outcomes, the proposed work will result in a new sea ice fragmentation module delivered to climate and weather modelling groups: within the UK, the Met Office, the National Oceanography Centre, the British Antarctic Survey, and the European Centre for Medium-Range Weather Forecasts.

北极海冰是气候变化的一个重要因素和指标;过去几十年来海冰的迅速减少给科学家、政策制定者和公众敲响了警钟。海冰的消退导致了跨北极航运的增长，以及从海底提取矿物和化石燃料的计划。政府间气候变化专门委员会（气候专委会）的最新评估得出结论，假设温室气体排放继续增加，到2050年北极可能会可靠地成为无冰地区。然而，IPCC使用的气候模拟往往无法真实地捕捉北极海冰的大尺度特性，如范围，变化和最近的趋势。因此，有必要改进北极海冰的模拟，以便更好地了解最近观测到的变化和对未来的可信预测，从而帮助评估风险和机会，并为关于适应和减缓的重要政策决定提供信息。新的卫星正在从太空测量海冰厚度和地形，最近和计划中的大量实地方案有助于我们了解控制冰盖演变的现场过程。这些观测结果不仅揭示了北极冰盖的范围和厚度在所有季节都在减少，而且还向我们展示了冰是如何减少的。特别是，最近的观察表明，表面融化池如何削弱冰，将其破碎成许多浮冰。没有一个关于海冰演变的实用环境或气候模型考虑到冰的碎裂过程或具有一系列不同大小的海冰的影响。海冰的大小影响横向融化，空气到海洋的动量传递，流变学和波冰相互作用。理想化模型研究表明，占浮冰破碎海冰的空间分布有一个领先的顺序的影响，并减少其整体范围和体积。由于现有的气候模型不包含这种物理学，它们在理解和预测北极的变异性和变化方面的效用受到了损害。由于纬向大气和海洋环流的误差，以及北极的冰输出，这也导致低纬度气候模型的准确性受损。这一提议将确定海冰碎裂在北极海冰加速消退中的作用。使用新的和新兴的观测，新的理论和过程建模相结合，我们将建立海冰破碎的基本理解。我们将a）开发一个高保真度，高分辨率的海冰热力学和机械演化模型，并利用这个模型和观测结果来探索海冰破碎，B）建立破碎过程的参数化，包括第一个融化破碎模型，并将这些模型纳入气候和天气模型的海冰部分，（c）利用冰-海和完全耦合的气候模式，查明碎裂对以下方面的贡献：过去几十年的快速冰损失，未来几十年冰损失的预测，以及现在为业务冰预测创造技能。除了科学成果，拟议的工作将产生一个新的海冰破碎模块，交付给气候和天气模拟小组：英国气象局、国家海洋学中心、英国南极调查局和欧洲中期天气预报中心。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Multi-scale satellite observations of Arctic sea ice: new insight into the life cycle of the floe size distribution.

DOI：
10.1098/rsta.2021.0259
发表时间：
2022-10-31
期刊：
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
影响因子：
5
作者：
Hwang, Byongjun;Wang, Yanan
通讯作者：
Wang, Yanan

Summer sea ice floe size distribution in the Arctic: High-resolution optical satellite imagery and model evaluation

北极夏季海冰浮冰尺寸分布：高分辨率光学卫星图像和模型评估