Collaborative Research: Rapic Climate Change due to Sea Ice Dynamics in the North Atlantic and Arctic Oceans

该项目的重点是研究由格陵兰冰芯记录的Dansgaard-Oeschger （D-O）事件引起的北大西洋和北极海洋海冰范围变化所驱动的快速气候变化。最近的一项模拟研究表明，海冰的适度减少可以解释格陵兰冰芯中记录的温度和积雪的突然变化。这个项目要解决的科学问题是：1)为什么海冰范围会突然变化；2)为什么新的状态持续了几个世纪，然后逐渐崩溃回原来的冰川状态；3)这如何解释其他地方的气候突变？研究人员的研究将受到这样一种假设的指导：耦合热带气候系统的突然重新配置是长期存在的，并通过大气或海洋环流的远距联系影响热带以外的气候，只需要温盐环流的适度变化就可以驱动海冰变化，从而导致格陵兰岛记录的大规模快速气候变化。研究生和本科生将在该项目中扮演主要角色，其结果将影响研究人员所教授的海洋学、气候与气候变化、气候模拟和应用数学课程。该项目还代表了气候动力学家、古气候数据专家和气候建模专家之间的合作，为解决基本的古气候问题提供了坚实的跨学科方法。气候模式和代理数据的协同作用有望在指导未来模式发展方面发挥作用。

The focus of this project is the study of rapid climate change driven by changes in sea ice extent in the North Atlantic and Arctic oceans, motivated by Dansgaard-Oeschger (D-O) events recorded in the Greenland ice cores. A recent modeling study suggests that a modest reduction in sea ice can account for the abrupt changes in temperature and snow accumulation recorded in the Greenland ice core. The science questions which this project will address are: 1) Why did the sea ice extent change suddenly; 2) Why did the new state persist for several centuries before gradually collapsing back to its original glacial state; and 3) How does this explain abrupt climate changes elsewhere? The investigators will be guided in their research by the hypothesis that abrupt reconfigurations in the coupled tropical climate system are long-lived and influence the climate outside of the tropics via teleconnections through the atmosphere or ocean circulation, requiring only a modest change in the thermohaline circulation to drive sea ice changes that cause the large rapid climate changes recorded in Greenland.Graduate and undergraduate students are to play major roles in this project, and the results will influence courses taught by the investigators in oceanography, climate and climate change, climate modeling, and applied math. The project also represents a collaboration between climate dynamicists, paleoclimate data experts, and climate modeling experts, providing a solid cross-disciplinary approach to address a fundamental paleoclimate issue. The synergy of climate modeling and proxy data is expected to prove useful in guiding future model development.