Interacting ice Sheet and Ocean Tipping - Indicators, Processes, Impacts and Challenges (ISOTIPIC)

冰盖和海洋倾覆的相互作用 - 指标、过程、影响和挑战 (ISOTIPIC)

• 批准号: NE/Z503344/1
• 负责人: Antony Payne
• 金额: $ 216万
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FZ503344%2F1
• 关键词: Interacting; ice; Sheet; Ocean; Tipping

The aim of this project is to understand the processes controlling key tipping points (TPs) associated with the oceans and ice sheets, and assess their potential impacts on society and the global Earth system. The specific Tipping Elements (TEs) to be considered are related to the Atlantic Ocean Meridional Overturning (AMOC), the Greenland ice sheet (GrIS), coastal upwelling in the Southern Ocean (SO) and the Antarctic ice sheet (AIS). These TEs are a coherent subset of the TEs widely discussed in the literature. They (a) share relatively long timescales and therefore similar analysis methodologies are likely to be appropriate; (b) are potentially linked in tipping cascades such as the SO circulation interacting with AIS instability and GrIS meltwater impacting AMOC stability, as well as potential bi-polar interactions; and (c) share the hugely important impact of sea level rise.Work Package 1 focuses on AMOC and GrIS and their interaction; while Work Package 2 focuses on AIS and interactions with the SO. The overall objective in both is to constrain the circumstances under which the relevant TEs either have been or could potentially be triggered in the future; as well as addressing the long-term response of the TE to assess, in particular, under what circumstances the tipping becomes truly irreversible. These improvements in understanding lead into the identification of potential Early Warning indicators in Work Package 3, while Work Package 4 will assess the societal and climatic impacts of tipping focusing on projected regional sea level rise and global climate.The Topic A call identifies five research questions, all of which should be tackled.What are the global and regional impacts and risks associated with key climate TPs? Work Package 4 focuses on impact, in particular the key impact of regional sea level rise with links to the communities designing storm surge barriers and developing adaptive management approaches. This work package will also investigate the wider impacts of tipping on global climate using UKESM, for instance on changing monsoon patterns.Is there evidence for abrupt changes and TPs in the latest ESMs? Many of the current generation of ESMs (in particular those used in CMIP6) do not contain the appropriate coupling for ice sheet TPs so that we will use models of the ice sheets either as standalone or coupled to regional ocean and atmosphere models to assess tipping. Forcing for these experiments will come from both UKESM and the wider CMIP6 ensemble.How do the risks of TPs vary in scenarios that overshoot the Paris 1.5°C and 2°C targets? Our Work Packages 1 and 2 will determine thresholds for tipping for TPs associated with both ice sheets and the Atlantic Meridional Overturning Circulation, which can then be related back to the Paris targets.How do we design the best early warning systems for specific TPs such as Atlantic meridional overturning circulation shutdown, ice-sheet collapse, or forest dieback? Our approach in Work Package 3 is to test a range of statistical early warning indicators by applying them to the outputs of models that are known to tip to determine which indicators are able to predict this tipping and on what timescales.Where is there evidence of changing system resilience in observational records? Having tested these indicators, Work Package 3 will apply them to observational records.

该项目的目的是了解控制与海洋和冰盖相关的关键临界点（TP）的过程，并评估其对社会和全球地球系统的潜在影响。要考虑的特定倾翻要素（TE）与大西洋经向翻转（AMOC）、格陵兰冰盖（GrIS）、南大洋（SO）沿海上升流和南极冰盖（AIS）有关。这些TE是文献中广泛讨论的TE的一致子集。它们（a）具有相对较长的时间尺度，因此类似的分析方法可能是适当的;（B）在倾翻级联中有潜在的联系，例如SO环流与AIS不稳定性的相互作用和影响AMOC稳定性的GrIS融水，以及潜在的两极相互作用;（c）具有海平面上升的巨大重要影响。而工作包2侧重于AIS和与SO的交互。两者的总体目标都是限制已经触发或将来可能触发相关TE的情况;以及解决TE的长期响应，以评估特别是在什么情况下倾翻变得真正不可逆转。这些认识的提高导致在工作包3中确定潜在的预警指标，而工作包4将评估倾倒的社会和气候影响，重点关注预计的区域海平面上升和全球气候。主题A呼吁确定了五个研究问题，所有这些问题都应该解决。第4套工作包侧重于影响，特别是区域海平面上升的主要影响，并与设计风暴潮屏障和制定适应性管理办法的社区建立联系。该工作包还将使用UKESM调查倾翻对全球气候的更广泛影响，例如对季风模式变化的影响。许多当前一代的ESM（特别是CMIP 6中使用的ESM）不包含冰盖TP的适当耦合，因此我们将使用冰盖模型作为独立模型或与区域海洋和大气模型耦合来评估倾翻。这些实验的推动力将来自UKESM和更广泛的CMIP 6集合。在超过巴黎1.5°C和2°C目标的情景中，TP的风险如何变化？我们的工作包1和2将确定与冰盖和大西洋经向翻转环流相关联的TP的临界值，然后可以将其与巴黎目标联系起来。我们如何设计针对特定TP的最佳预警系统，如大西洋经向翻转环流关闭，冰盖崩溃或森林枯死？我们在工作包3中的方法是测试一系列统计预警指标，将其应用于已知倾斜的模型输出，以确定哪些指标能够预测这种倾斜以及在什么时间尺度上。观察记录中哪里有改变系统弹性的证据？在测试了这些指标之后，工作包3将把它们应用于观测记录。