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》的全部或部分资助的。该项目将从中央赤道赤道太平洋中恢复过的古代珊瑚，以研究持续1000年的气候条件。 ，奖章的气候异常（850-1300以前）要研究研究人员的每月分辨率。 -16教育和公众强调在附近的少数派服务中扩大多样性和代表性不足的社区。内部与外部的迫使热带气候变化在珊瑚的基于珊瑚的古abe中，急剧改善了我们对热带的国际气候变化的理解，但是，由于对百年纪念的变化而言，类似的见解。 （i）珊瑚代理中可能会显着偏向珊瑚重建 - 殖民地的偏移，这在估计单个珊瑚的平均气候变化中引入了大型不确定性。在过去的千年中生成了〜50个新的良好和多核变异性记录。中世纪气候异常（MCA; 900-1200CE）和少量冰期（1500-1800CE）的太平洋表面温度（SST）和氢化气候趋势（1500-1800ce）。从改变的珊瑚中提取可靠的气候。通过为气候模型提供更多的基准，可以改善热带太平洋的自然责任。以及来自附近学区的高中生的夏季经验，该地区有9％的少数群体派出。该奖项反映了NSF'Stutory Mission，并使用基金会的知识分子优点和更广泛的影响审查标准，以值得评估。