Earth System Modelling of Abrupt Climate Change

最近对气候突变的研究倾向于关注与大西洋经向翻转环流突然停止或减少有关的快速冷却事件。然而，格陵兰岛跨越末次冰期到间冰期（大约10万年）的冰芯记录表明，在几十年内发生的10摄氏度量级的突然变暖更能代表过去的气候记录。此外，尽管仍然缺乏明确的认识，但最近的建模工作表明，大气动力学在形成这些突发事件方面可能比以前认为的更为重要。因此，我们建议使用一个地球系统气候模式，该模式可以定量模拟格陵兰冰中记录的多种代用物（包括温度、甲烷和灰尘），以评估哪些强迫模式可以与这些多个冰芯数据约束相协调。我们将进行敏感性分析，以评估大气突变阈值的可能性，并研究它们对冰川地形和背景气候状态的依赖。因此，这个项目将是第一个在一个单一的、定量的大气环流模拟框架中综合许多关于气候突变的冰芯记录的项目，其结果将对我们过去和未来对气候突变的理解产生重大的新限制。

Recent studies of abrupt climate change have tended to focus on rapid cooling events related to an abrupt cessation or reduction in the Atlantic meridional overturning circulation. However, ice core records from Greenland which span the last glacial to interglacial cycle (approximately 100,000 years) indicate that abrupt warmings of the order of 10C, which took place in a few decades, are more representative of the past climatic record. Furthermore, although a clear understanding is still lacking, recent modelling efforts suggest that atmospheric dynamics could be more important in shaping these abrupt events than previously thought. We propose therefore to use an Earth System climate model which can quantitatively simulate multiple proxies recorded in Greenland ice (including temperature, methane and dust) to assess which patterns of forcings can be reconciled with these multiple ice core data constraints. We will perform sensitivity analyses to assess the potential for thresholds of abrupt atmospheric transitions and investigate their reliance on glacial topography and background climatic state. This project will therefore be the first to synthesise a number of ice-core records of abrupt climate change in a single, quantitative general circulation modelling framework and the results will place significant new constraints on our understanding of abrupt climate change in the past, and potentially in the future.