Earth System Modelling of Abrupt Climate Change

点击翻译按钮获取中文摘要

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.