P2C2: Rapid Climate Variations--A Speleothem-based High-resolution Record of Rainfall in the Equatorial South Pacific over the Last 83,000 Years

P2C2：气候快速变化——基于洞穴的高分辨率赤道南太平洋过去83,000年降雨记录

• 批准号: 1103478
• 负责人: Robert Sherrell
• 金额: $ 52.82万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1103478&HistoricalAwards=false
• 关键词: P2C2; Rapid; Climate; Variations; Speleothem

This project seeks to generate a Uranium/Thorium (U/Th) dated record of rainfall in the southern tropical Pacific at sub-century (~50 year/sample) resolution for most of the glacial and Holocene periods using stalagmites from the island of Niue and from Tonga. The speleothem from Niue dates to 83,000 years before the present. Specifically, the researchers will: 1) analyze the Niue specimen, as well as a Holocene-age stalagmite from Tonga, for Oxygen-18, Carbon-13, Magnesium/Calcium ratios, Strontium/Calcium ratios, and Barium/Calcium ratios; 2) generate a precise absolute-dated U/Th age model for the specimens; and 3) undertake drip-water sampling to validate paleoclimate interpretations. The goal of the project is to examine the following hypotheses: a) at times of increased Thermohaline Circulation (THC), a northward shift of the Pacific Inter-tropical Convergence Zone (ITCZ) dominated over a westward shift in the Walker Cell resulting in decreased rainfall at Niue; and b) rainfall records at Niue will show rapid shifts in phase with Greenland ice-core records, but will also show additional changes characteristic of Antarctic temperature records.The broader impacts include the potential for a high-quality paleoclimate record from an important and under-studied region. In addition to the scientific importance and support of a graduate student, the researcher will conduct outreach through a NSF-sponsored program through which high-school students and teachers from New Jersey participate in workshops on marine and climate science.

该项目旨在利用纽埃岛的石笋，生成大部分冰川期和全新世时期南热带太平洋亚世纪（约 50 年/样本）分辨率的铀/钍 (U/Th) 降雨记录。和来自汤加。 纽埃的洞穴化石可以追溯到距今 83,000 年前。 具体来说，研究人员将：1）分析纽埃标本以及来自汤加的全新世石笋的氧18、碳13、镁/钙比、锶/钙比和钡/钙比； 2) 为标本生成精确的绝对日期U/Th年龄模型； 3) 进行滴水采样以验证古气候解释。该项目的目标是检验以下假设：a) 在温盐环流 (THC) 增加时，太平洋热带辐合带 (ITCZ) 的北移主导了沃克环流的西移，导致温盐环流 (THC) 减少纽埃降雨； b) 纽埃的降雨记录将显示出与格陵兰冰芯记录同相的快速变化，但也将显示出南极温度记录的其他变化特征。更广泛的影响包括从重要和欠缺的地区获得高质量古气候记录的潜力。 -研究地区。除了研究生的科学重要性和支持外，研究人员还将通过美国国家科学基金会资助的一项计划进行推广，新泽西州的高中生和教师可以通过该计划参加海洋和气候科学研讨会。