Collaborative Research: Patterns and processes of abrupt Arctic warming based on paleoclimate observations and models

在过去的50年里，北极变暖的速度可能比过去7000年中的任何时候都要快，而且在接下来的几个世纪里，气温可能会继续上升。这项研究使用地质证据和模型模拟来研究北极系统对过去变暖事件的反应，这些变暖事件的速度和持续时间与现代变暖相似。该项目提供了对与北极突然变暖事件相关的温度和海洋-大气环流变化的详细见解，从而更好地了解了对未来变暖的潜在反应。通过外展努力，该项目将服务不足社区的K-12学生与高等教育机会联系起来，并支持包括研究生和本科生在内的多名早期职业研究人员。最后，该项目产生的数据库和模型输出将以社区标准格式和档案公开，从而加速北极科学在该项目生命周期之外的进步。这项研究侧重于决定北极系统多个组成部分之间相互作用的反馈和过程，因为它们在最近的脱冰期经历了快速变暖：海冰、海洋和大气耦合以及北极陆地气候。该项目验证了一种假设，即在过去的突然变暖事件中，北极温度和水分的变化呈现出共同的空间模式，强烈地受到海冰变化和水分输送路径的接近程度的控制。研究人员采用了一种三管齐下的方法：(1)通过生成新的古气候数据-特别是基于化合物特定同位素的新的水文气候推断和基于大量新的放射性碳年龄的更准确的年代学控制-来量化气候对三个突然变暖时期(14,500年；11,700年和8,000年前)的响应；(2)使用更新的北极范围的古气候数据库重建与这些突然变暖事件相关的时空模式；以及(3)将古气候数据库与现有的和新的全球气候模拟进行比较，包括那些使用最先进的同位素启用的模型来评估突然变暖期间北极组成部分和全球气候系统之间的机械联系的那些。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The rate at which the Arctic has warmed during the past 50 years is likely faster than anytime during the past 7 millennia, and temperatures will likely continue to rise during the coming centuries. This research uses geological evidence and model simulations to study the Arctic system’s response to past warming events that had similar rate and duration to that of modern warming. This project provides detailed insights into the temperature and ocean-atmosphere circulation changes associated with abrupt warming events in the Arctic, thus providing a better understanding of the potential response to future warming. Through outreach efforts, this project connects K–12 students in underserved communities to higher-education opportunities and supports multiple early career researchers, including graduate and undergraduate students. Finally, the database and model output generated from this project will be made publicly available in community-standard formats and archives, thus accelerating advances in Arctic science beyond the life of this project.This study focuses on the feedbacks and processes that determine the interactions of multiple components of the Arctic system as they have undergone rapid warming during the recent deglacial period: sea ice, coupled ocean and atmosphere, and terrestrial Arctic climate. This project tests the hypothesis that during past abrupt warming events, Arctic temperature and moisture changes exhibit a common spatial pattern, strongly controlled by proximity to sea-ice changes and paths of moisture transport. The researchers employ a three-pronged approach: (1) Quantify the climate response to three periods of abrupt warming (14,500; 11,700; and 8,000 years ago) by generating new paleoclimate data — specifically new hydroclimate inferences based on compound-specific isotopes and more accurate chronological control based on a large number of new radiocarbon ages — using existing lake sediment cores from sites that fill major data gaps; (2) Reconstruct the spatiotemporal pattern associated with these abrupt warming events using an updated Arctic-wide paleoclimate database; and (3) Compare the paleoclimate database with existing and new global climate simulations, including those using state-of-the-art isotope-enabled models to assess mechanistic links between components of the Arctic and global climate system during abrupt warming.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.