Collaborative Research: Central tropical Pacific climate variability over the last millennium

合作研究：过去千年中部热带太平洋气候变化

• 批准号: 2103035
• 负责人: Alyssa Atwood
• 金额: $ 7.32万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2103035&HistoricalAwards=false
• 关键词: Collaborative; Research; Central; tropical; Pacific

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The project will assemble radiocarbon-dated segments of ancient coral recovered from islands in the central equatorial Pacific to study climate conditions during the last 1000 years. It will focus on two important time periods, the Medieval Climate Anomaly (850-1300 ago) and the Little Ice Age (1400-1850) to look at what factors cause El Nino conditions. Researchers will reconstruct monthly-resolution records of seawater temperature and salinity conditions by targeting growth bands in coral skeletons. This project supports research training educational opportunities for several undergraduate and graduate students. It also supports a research collaboration among two early career scientists and others who have a strong track record of participation in K-16 education and public outreach with an emphasis on broadening diversity and inclusion of underrepresented communities. These efforts will continue with guest lectures at a nearby minority-serving institution and by offering summer research opportunities for local high school students.Improving the accuracy of future climate projections requires a more complete understanding of internal vs. externally forced changes in tropical Pacific climate on a broad range of timescales. Coral-based paleoclimate records have dramatically improved our understanding of interannual climate variability in the tropical Pacific, however, similar insights into centennial-scale variability have thus far remained unattainable due to (i) diagenesis, which can significantly bias coral reconstructions, and (ii) colony-to- colony offsets in coral proxies, which introduce large uncertainties in estimates of mean climate change from single corals. Informed by two decades of work at Kiritimati Island (2degN, 157degW), this project will generate ~50 new well-dated and multi-proxy records of climate variability across the last millennium. Using a novel approach that layers paired coral oxygen isotope and Sr/Ca measurements, with a new paleothermometer, Sr-U, this reconstruction will provide the first set of robust, quantitative, and independent estimates of central tropical Pacific surface temperature (SST) and hydroclimate trends across the Medieval Climate Anomaly (MCA; 900-1200CE) and Little Ice Age (LIA; 1500-1800CE). The fidelity of these fossil coral records will be further ensured using rigorous screening for diagenesis and a microscale analyses to extract reliable climate information from altered corals. Comparisons of these new reconstructions with transient climate simulations will provide much-needed context for present-day trends and allow us to investigate the tropical Pacific’s long-term response to external forcings and climate feedbacks. Broader impacts to this project include a dramatic improvement to our understanding of natural climate variability in the tropical Pacific, allowing for the better quantification of regional anthropogenic climate trends, and the improvement of future climate projections by providing more accurate benchmarks for climate models. As climate change continues to dominate social consciousness, the PI will actively engage in public outreach efforts to communicate the results of the paleoclimate research as well as more general information about local/regional impacts of future climate change. It supports research training and mentoring of several graduate students and summer research experiences for high school students from a nearby school district which has a 90% underrepresented minority student population.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.

该奖项是根据2021年《美国救援计划法》（公法117-2）全部或部分资助的。该项目将组装从中央太平洋中部岛屿岛上回收的古代珊瑚的放射性阶段，以研究过去1000年的气候条件。它将集中于两个重要的时期，即中世纪的气候异常（850-1300以前）和小冰河时代（1400-1850），以查看哪些因素导致埃尔尼诺的条件。研究人员将通过针对珊瑚骨骼的生长带来重建海水温度和盐度条件的每月分辨率记录。该项目为几位本科生和研究生提供了研究培训教育机会。它还支持两位早期职业科学家和其他人在参与K-16教育和公众宣传方面有很强记录的研究合作，重点是扩大多样性和包括代表性不足的社区。这些努力将继续在几乎少数派服务机构的嘉宾演讲中，并通过为当地高中生提供夏季的研究机会。展现未来气候项目的准确性，需要在广泛的时间表上对热带太平洋气候的内部和外部强迫变化有更全面的了解。 Coral-based paleoclimate records have dramatically improved our understanding of interannual climate variability in the tropical Pacific, however, similar insights into centennial-scale variability have thus far remained unattainable due to (i) diagenesis, which can significantly bias coral reconstructions, and (ii) colony-to-colony offsets in coral proxies, which introduce large uncertainties in estimates of mean climate change from single珊瑚。在Kiritimati Island（2DEGN，157DEGW）的二十年工作中，该项目将在上一个千年中产生约50个新的良好的日期良好且多毒的气候变化记录。使用一种新的方法，该方法将配对的珊瑚氧同位素和SR/CA测量与新的浅热量计SR-U一起使用，该重建将提供第一组对中央热带太平洋表面温度（SST）中心中心的稳健，定量和独立估计，以及整个中世纪气候冰的冰原冰原（MCA）（MCA）; 900-100-100-100-12cy; 900-100-100-12cy; 900-12ce; 900-100-100-100-100-100-1200）。这些化石珊瑚记录的忠诚度将进一步确保，使用严格的成岩作用和微观分析，以从改变的珊瑚中提取可靠的气候信息。这些新重建与瞬态气候模拟的比较将为当今的趋势提供急需的环境，并允许我们调查热带太平洋对外部强迫的长期反应并攀登反馈。对该项目的更广泛影响包括我们对热带太平洋自然气候变异性的理解的显着改善，从而可以更好地量化区域人为气候趋势的量化，​​以及通过为气候模型提供更准确的基准，从而改善未来的气候项目。随着气候变化继续占据社会意识，PI将积极参与公共宣传工作，以传达古气候研究的结果以及有关未来气候变化的本地/地区影响的更多一般信息。它支持几位研究生的研究培训和心理化，以及来自近学区的高中生的夏季研究经验，该学区的少数族裔学生人数不足90％。这项奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的审查标准通过评估来通过评估来支持的。