Abrupt climate and sea level change

这个博士项目将使用数值模拟来研究气候和海平面快速变化的原因和后果。过去冰川消融的案例研究将被用来达到一个新的理解水平，即冰盖融化与海平面上升、快速冷却、突然变暖以及大西洋环流的彻底重组之间的联系。在最后一次冰川盛期(2.1万年前)，巨大的冰盖覆盖了北半球的大部分地区。随着气候变暖，冰层开始融化，引发了一系列耐人寻味的灾难性事件：大规模海洋环流放缓，气候降温，冰山舰队被释放，海平面以前所未有的速度上升，海洋环流迅速加强，气温在几十年内突然上升了几度……然后这一切在短短几个世纪后再次发生。尽管各个事件都有很好的记录，但我们仍然不清楚这些事件是如何联系在一起的，甚至是不是联系在一起。也许更有趣的是，我们知道许多事件在地球过去曾反复发生，这表明地球系统中存在一致但目前尚不清楚的触发气候突然变化的机制。科学界对这些事件的原因仍然存在分歧，但人们一致认为，了解这些机制对于预测它们将在何时发生非常重要。随着未来几年大气二氧化碳的增加，格陵兰岛和南极冰盖继续融化，这些灾难性的事件会再次引发吗？这个令人兴奋的项目将直接应对这一挑战，测试在冰川消融期间发生的冰-海洋-大气相互作用，以产生关于我们气候的开创性新知识。您将是两个制作过去突然气候变化的新模型模拟和观测记录的国际项目的核心：古气候模型对比项目(PMIP)冰川消融工作组和国际第四纪研究联盟冰川消融重点小组，两者都由Ruza Ivanovic博士协调。因此，你将有机会接触到世界领先科学家的最新结果和想法，处于过去变暖气候国际研究的前沿，你将有机会进入全球研究议程。项目目的你将运行和分析复杂的地球系统数值模型，以研究气候、冰盖、冰山和海洋环流之间的相互作用。您将把这些模拟的结果与观测记录进行比较，以评估模型的性能，验证/驳斥对事件的现有解释，并建立和测试新的假设。总体目标是建立连接地球系统中冰、大气和海洋的机制，然后探索我们过去所知的这种快速和灾难性的事件在未来再次发生的可能性。

This PhD project will use numerical modelling to examine the causes and consequences of rapid climate and sea level change. Case studies from past deglaciations will be utilised to reach a new level of understanding for the link between ice sheet melting and sea level rise, rapid cooling, abrupt warming and the complete reorganisation of Atlantic Ocean circulation.At the Last Glacial Maximum (21,000 years ago), vast ice sheets stretched across much of the Northern Hemisphere. As climate warmed and the ice began melting, an intriguing and catastrophic chain of events was triggered: Largescale ocean circulation slowed, climate cooled, armadas of icebergs were released, sea level rose at an unprecedented rate, ocean circulation rapidly strengthened, temperatures suddenly increased by several degrees in a few decades...and then it all happened again just a few centuries later. Although well documented individually, we still do not know precisely how and even if these events are linked. Perhaps even more intriguingly, we know that many of the events have occurred repeatedly in Earth's past, suggesting there are consistent but currently unknown mechanisms in the Earth System for triggering abrupt climate change.The scientific community remains divided on the cause of the events, but there is consensus that the mechanisms are important to understand in order to predict when they will occur. As atmospheric CO2 rises in the coming years, and the Greenland and Antarctic ice sheets continue to melt, could these catastrophic events be triggered again?This exciting project will tackle this challenge directly, testing ice-ocean-atmosphere interactions that take place during deglaciations in order to produce seminal new knowledge on our climate. You will be at the heart of two international projects producing new model simulations and observational records of past abrupt climate change: The Paleoclimate Model Intercomparison Project (PMIP) Deglaciations Working Group and The International Union for Quaternary Research Focus Group on Deglaciations, both coordinated by Dr. Ruza Ivanovic. Thus, you will be granted access to the latest results and thinking from world-leading scientists, and, positioned at the forefront of international research into past warming climates, you will have the opportunity to feed into the global research agenda.PROJECT AIMYou will run and analyse complex numerical earth system models to examine the interplay between climate, ice sheets, icebergs and ocean circulation. You will compare the results from these simulations to observational records to evaluate model performance, verify/refute existing explanations for the events, and build and test new hypotheses. The overall aim is to establish the mechanisms that link ice, atmosphere and ocean in the Earth System, then explore the possibility that such rapid and catastrophic events as we know have occurred in the past will occur again in the future.