Intra-Annual Radiocarbon (14C) Offsets, Chronology and Paleoclimate

年内放射性碳 (14C) 偏移、年代学和古气候

• 批准号: 2303502
• 负责人: Sturt Manning
• 金额: $ 50万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2303502&HistoricalAwards=false
• 关键词: Intra; Annual; Radiocarbon; 14C; Offsets

This project specifically aims to test whether small growing-season-related Carbon-14 offsets exist for two Mediterranean-type areas comprised of the East Mediterranean-Middle East (EMME) and the Southwest United States (SW USA), as well as one humid sub-tropical area Southeast United States (SE USA), and, if identified, quantify their scale and paleoclimate relevance.Carbon-14 is relevant to many temporally-dependent investigations in paleoclimate and related fields, as well as a key tracer for a number of carbon-cycle models central to paleoclimate research. Recent studies have revealed a distinct seasonal cycle in atmospheric Carbon-14. With high-precision measurement it seems plausible that plants growing at substantially different times of the year may reflect different portions of this seasonal Carbon-14 cycle. This research has the potential to advance knowledge in the fields of paleoclimate, paleoecology, and archaeology. Precise age-depth modelling is critical to establishing the timing of past events, and the research will attempt to improve radiocarbon age calibration by investigating the potential impacts of seasonal phenological differences in annual radiocarbon uptake by plants and how those biases may impact calibration based on widely used but spatially-biased northern hemisphere calibration curve.Until recently, analytical precision precluded exploring such differences since they were below measurement detection but advances in analytical measurements now make this inquiry possible. Although small, these analytical differences could have significant effects on carbon-related dating, especially at times of reversals and plateaus in the Carbon-14 calibration curve. The potential Broader Impacts include involving undergraduates in dendrochronology research at both Cornell University and the University of Georgia while also supporting an early career scientist at Georgia. The project would also support a PhD student who will develop outreach materials for the public. Research results will be distributed during International Archaeology Day and outreach to middle school students through the Expanding Your Horizons (EYH) program in Ithaca, New York.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.

该项目专门旨在测试两个地中海型地区是否存在与东地中海中部东部（EMME）和西南美国（SW USA）组成的两个地中海类型地区（SW USA），以及一个潮湿的亚光次亚光群区域（SE USICATICTIANS），以及量表，并将其相关性，并确定了一个比例。在古气候和相关领域进行的时间依赖性研究，以及对古气候研究中心的许多碳循环模型的关键示踪剂。最近的研究表明，大气碳14的季节性周期不同。通过高精度的测量，在一年中实质上不同的时间生长的植物可能反映了本季节性碳14周期的不同部分，这似乎是合理的。这项研究有可能提高在古气候，古生态学和考古学领域的知识。 Precise age-depth modelling is critical to establishing the timing of past events, and the research will attempt to improve radiocarbon age calibration by investigating the potential impacts of seasonal phenological differences in annual radiocarbon uptake by plants and how those biases may impact calibration based on widely used but spatially-biased northern hemisphere calibration curve.Until recently, analytical precision precluded exploring such differences since they were below测量检测但分析测量的进展现在使此查询成为可能。尽管很小，但这些分析差异可能会对碳相关的约会产生重大影响，尤其是在碳-14校准曲线中的逆转和高原时。潜在的更广泛的影响包括在康奈尔大学和佐治亚大学参与大学生学研究的本科生，同时还支持佐治亚州的早期职业科学家。该项目还将支持一位将为公众开发外展材料的博士生。研究结果将在国际考古日期内分发，并通过在纽约Ithaca扩大您的视野（EYH）计划向中学生宣讲。该奖项反映了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影响的审查标准通过评估来进行评估的。