Collaborative Research: Seasonal climate change over the last two millennia from archaeological sources in the subtropical eastern North Atlantic region

在过去的两千年里，亚热带海岸的海表温度（SST）的季节范围是如何变化的？亚热带沿海地区工业化前气候的季节性记录很少，但对于了解对人类和生态系统的影响至关重要。本研究的目标是重建夏季和冬季SST在四个温暖与寒冷的气候间隔，从过去两千年。这将通过使用保存在加那利群岛土著居民积累的考古沉积物中的贝壳中的古气候代理（SST的间接测量）来实现。其成果将促进人类与气候相互作用的知识，例如气候变化对史前人类生存模式和生态敏感栖息地行为的长期影响。该项目将培训从高中到博士水平的学生，目标是来自低收入家庭的本科生，第一代大学生和代表性不足的民族群体的成员，使用既定的计划，包括麦克奈尔学者，妇女在科学和工程，和向上拓展计划。通过在科学教学计划的学士学位教育，未来的高中地球科学教师将进行研究，将产生实验室课程的K-12科学课程。该项目促进了美国和西班牙科学家之间的国际和多学科合作。结果将以英语和西班牙语向专家和公众传播，这将吸引美国和其他地方的不同受众。 使用氧同位素（δ 18 O）的时间序列的放射性碳定年考古髌骨candei（软体动物：腹足纲）贝壳从加那利群岛，几个关键的突然的几百年的变暖和变冷的转变（罗马温暖期，汪达尔最低或黑暗时代冷期，中世纪气候异常，小冰期）将被检查和比较到20世纪后期的世纪。主要目标是：（1）校准和验证P. candei活标本的氧同位素年代学（贝壳生长模式），并将仪器记录作为季节性SST的可靠存储库;（2）在过去2000年与我们快速变暖的世界相关的重要突发气候间隔期间，从放射性碳年代测定的考古贝壳重建SST剖面。这项调查的结果将用于探索北大西洋涛动（NAO）的时间变化，这是北大西洋大气变化的一个关键特征，主要在冬季运行。这个地理位置提供了一个独特的机会来研究NAO阶段及其在工业化前气候变暖和变冷期间亚热带锋的变化。这个奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持的。

How has the seasonal range in sea surface temperature (SST) changed over the last two millennia along subtropical coasts that are inherently sensitive to human and climate impacts? Seasonally-resolved records of preindustrial climate in subtropical coastal settings are few but critical to understanding impacts on humans and ecosystems. The goal of this research is to reconstruct summer and winter SST during four warm vs. cold climate intervals from the last two millennia. This will be achieved using paleoclimate proxies (indirect measures of SST) preserved in shells from archaeological deposits accumulated by aboriginal people in the Canary Islands. Outcomes will advance knowledge of human-climate interactions, such as the long-term effects of climate variability on prehistoric human subsistence patterns and behavior in ecologically sensitive habitats. This project will train students from high school to PhD level, targeting undergraduate students from low-income households, first-generation college students, and members of under-represented ethnic groups, using established programs including McNair Scholars, Women in Science and Engineering, and Upward Bound Programs. Through the UNC Baccalaureate Education in Science & Teaching program, future high-school earth science teachers will perform research that will generate laboratory curricula for K-12 science courses. This project fosters international and multidisciplinary collaboration among scientists from the US and Spain. Results will be disseminated to both specialists and the general public in both English and Spanish, which will engage a diverse audience in the US and elsewhere. Using oxygen isotope (delta18O) time-series of radiocarbon-dated archaeological Patella candei (Mollusca: Gastropoda) shells from the Canary Islands, several critical abrupt multi-centennial warming and cooling transitions (Roman Warm Period, Vandal Minimum or Dark Ages Cool Period, Medieval Climate Anomaly, and Little Ice Age) will be examined and compared to the late 20th century. The main goals are to: (1) calibrate and validate oxygen isotope sclerochronology (shell growth patterns) of living specimens of P. candei with instrument records as credible repositories of seasonal SST; and (2) reconstruct SST profiles from radiocarbon-dated archaeological shells during important abrupt climate intervals over the last two millennia relevant to our rapidly warming world. Results from this investigation will be then used to explore temporal variations of the North Atlantic Oscillation (NAO), which is a key feature of atmospheric variability in the North Atlantic and mainly operates during the winter. The geographic location offers a unique opportunity to examine the NAO phase and its shifts in the subtropical fronts during preindustrial warming and cooling climate episodes.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.