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

该项目的目的是了解与海洋和冰盖相关的关键临界点（TPs）的控制过程，并评估其对社会和全球地球系统的潜在影响。需要考虑的具体引爆要素（TEs）与大西洋经向翻转（AMOC）、格陵兰冰盖（GrIS）、南大洋沿岸上升流（SO）和南极冰盖（AIS）有关。这些te是文献中广泛讨论的te的一个连贯子集。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)可能与临界点级联有关，例如SO环流与AIS不稳定性相互作用，GrIS融水影响AMOC稳定性，以及潜在的双极相互作用；(c)共同承受海平面上升带来的巨大影响。工作包1侧重于AMOC和GrIS及其相互作用；而工作包2则侧重于AIS和与SO的交互。这两项措施的总体目标，都是限制在何种情况下会触发或可能在未来触发有关的排污管制措施；以及处理环境运输署的长期应对措施，特别是评估在何种情况下废物倾倒会真正不可逆转。这些认识上的改进有助于在工作包3中确定潜在的早期预警指标，而工作包4将评估倾倒的社会和气候影响，重点关注预测的区域海平面上升和全球气候。题目A确定了五个研究问题，所有这些问题都应该被解决。与主要气候tp相关的全球和区域影响和风险是什么？工作包4侧重于影响，特别是区域海平面上升的关键影响，并与设计风暴潮屏障和制定适应性管理方法的社区建立联系。该工作包还将使用UKESM调查小费对全球气候的更广泛影响，例如对季风模式变化的影响。在最近的esm中是否有突变和TPs的证据？当前一代的许多esm（特别是CMIP6中使用的esm）没有包含对冰盖tp的适当耦合，因此我们将使用冰盖模型，或单独使用，或与区域海洋和大气模型耦合使用，以评估倾倒。这些实验的动力将来自UKESM和更广泛的CMIP6集合。在超过《巴黎协定》1.5°C和2°C目标的情况下，tp的风险有何不同？我们的工作包1和工作包2将确定与冰盖和大西洋经向翻转环流相关的TPs的临界点，然后将其与巴黎目标联系起来。我们如何设计最好的预警系统，针对特定的TPs，如大西洋经向翻转环流关闭、冰盖崩塌或森林枯死？我们在工作包3中的方法是测试一系列统计预警指标，将其应用于已知会发生倾斜的模型的输出，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。哪里有观测记录中系统弹性变化的证据？在测试了这些指标之后，第三工作包将把它们应用于观测记录。

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.