Examining the glacial cycle phase space through data-integrated glacial systems modelling

过去是我们通向未来的模糊窗口。透过这个窗口，诱人的差异指向了我们对冰、地球和气候系统耦合的理解上的裂痕。过去13万年的冰和气候变化的历史提供了气候系统状态的重大变化以及突然的临界点行为的例子。*这个系统变化的动力来源仍然知之甚少。在解释末次冰盛期全球平均海平面(“冰缺失”的问题)以及在大约12.5万年前的最后一次(伊米亚)间冰期推断海平面上升6-10米的来源方面，也存在令人费解的*不足。对潜在气候变化的科学评估在很大程度上依赖于气候模型。尽管复制现代气候对模型来说是一项具有挑战性的测试，但这只是一项有限的测试，因为这些模型已经进行了*调整，以适应当前的环境。为了回答与气候系统潜在的巨大变化有关的问题*(特别是所谓的临界点)，最好对照过去对模型进行测试。对这些测试至关重要的是，对过去地形、冰盖和相关的融化水排入海洋的变化有信心地推断。这项拟议的研究将通过*先进的计算模型和大量不同的古数据集进行*统计上的稳健整合，显著改进这些推断。这将解决或进一步澄清失踪的冰层问题。该研究计划还将应用这些*精细的冰川年表来直接检查冰川冰和气候系统的可变性，模型*包括气候、冰盖和地球组成部分。*通过在这个框架内部署越来越复杂的模型，我们将测试*当前的模型和理解在多大程度上能够复制和解释过去的冰盖演化和不稳定事件。*这些测试反过来将有助于估计有关未来冰盖演变**和相关冰盖与气候系统相互作用的不确定性，解决当前气候*变化评估中的一个主要差距。

The past is our fuzzy window to the future. Through this window, tantalizing discrepancies point to cracks***in our understanding of the coupled ice, earth, and climate system. The last 130,000 year history of ice and***climate change offers major changes in the state of the climate system as well as examples of abrupt tipping***point behaviour.******The dynamical source of the variability of this system is still poorly understood. There are also perplexing***shortfalls in explaining inferred global mean sea level at Last Glacial Maximum (the problem of “missing***ice”) as well the source of an inferred 6-10 m higher sea level during the last (Eemian) interglacial, about***125,000 years ago.******Scientific assessments of potential climate change rely heavily on climate models. Though replication of***present-day climate is a challenging test for models, it is only a limited test since these models are already***tuned to fit the present. To answer questions related to potentially large changes in the climate system***(especially so-called tipping points), models are best tested against the past.******Critical to these tests is a confident inference of the past change in topography, ice cover, and associated***meltwater drainage into the ocean. The proposed research will significantly refine these inferences through***statistically robust integration of advanced computed models and large diverse sets of paleo data. This***will either resolve or further clarify the missing ice issue. The research program will also apply these***refined ice chronologies to direct examination of variability in the glacial ice and climate system with models***encompassing the climate, ice sheet, and earth components.******By deploying increasingly sophisticated models within this framework, we will test the extent to which***current models and understanding can replicate and explain past ice sheet evolution and instability events.***These tests will in turn facilitate the estimation of uncertainties concerning both future ice sheet evolution***and associated ice sheet interactions with the climate system, addressing a major gap in current climate***change assessments.