Validation of the Strontium-Uranium Thermometer Against Instrumental Records of Ocean Temperature

根据海洋温度仪器记录验证锶-铀温度计

• 批准号: 1747746
• 负责人: Anne Cohen
• 金额: $ 3.32万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1747746&HistoricalAwards=false
• 关键词: Validation; Strontium; Uranium; Thermometer; Against

Anthropogenic CO2 emissions are changing Earth's climate. Yet climate also varies naturally on timescales of decades to millennia. Characterizing this variability is critical to both quantifying the anthropogenic influence and projecting future change. Sea surface temperature (SST) plays a major role in climate yet the instrumental record is too short to enable a robust evaluation of natural variability. Proxy data generated from coral skeletons have potential to fill these gaps but generation of lengthy records requires use of dead colonies that grew before the instrumental era, for which existing geochemical SST proxies are not well-suited. A new thermometer, Sr-U, has been developed for application to non-living corals but the calibration to SST requires testing. This project seeks to validate Sr-U by reconstructing a record for the central Red Sea and comparing against well-constrained observational SSTs for the region. A successful outcome will benefit the scientific community by opening the global archive of non-living corals for SST reconstructions. Improved SST reconstructions will provide a target for the same numerical models used to predict future oceanographic and climate change.Coral-to-coral geochemical variability is a major obstacle to SST reconstructions from non-living corals and Sr-U is based on a robust understanding of the processes that cause this variability. This project will generate Sr/Ca and U/Ca data for the last 50 years from an existing Porites coral core sampled in the central Red Sea and apply a calibration derived from Atlantic species to reconstruct the SST record. Heavy ship traffic in the region means the pre-satellite observational record is well-constrained. Additionally, Red Sea SSTs over the last 50 years are characterized by decadal variability superimposed on a long-term warming trend, and thus present an ideal test of the ability of Sr-U to capture both variability and trends in an unknown coral. The goal is a proof-of-concept, to demonstrate the universal application of Sr-U as a tool with which to reconstruct accurate SST records using modern and fossil corals alike.

人为二氧化碳排放正在改变地球气候。然而，气候也会在数十年到数千年的时间尺度上自然变化。表征这种变异性对于量化人为影响和预测未来变化至关重要。海面温度（SST）在气候中起着重要作用，但仪器记录太短，无法对自然变化进行可靠的评估。从珊瑚骨骼生成的代理数据有可能填补这些空白，但生成冗长的记录需要使用仪器时代之前生长的死亡珊瑚群，而现有的地球化学海表温度代理不太适合。一种新的温度计 Sr-U 已开发用于非生物珊瑚，但海表温度的校准需要测试。该项目旨在通过重建红海中部的记录并与该地区严格约束的观测海表温度进行比较来验证 Sr-U。成功的成果将开放全球非活珊瑚档案用于海表温度重建，从而使科学界受益。改进的海表温度重建将为用于预测未来海洋和气候变化的相同数值模型提供目标。珊瑚间的地球化学变异性是非生命珊瑚海表温度重建的主要障碍，而 Sr-U 是基于对导致这种变异性的过程的深入了解。该项目将从红海中部采样的现有滨珊瑚核心生成过去 50 年的 Sr/Ca 和 U/Ca 数据，并应用来自大西洋物种的校准来重建海表温度记录。该地区船舶交通繁忙，意味着卫星前观测记录受到很大限制。此外，过去 50 年红海海表温度的特点是十年间的变化叠加在长期变暖趋势上，因此为 Sr-U 捕获未知珊瑚的变化和趋势的能力提供了理想的测试。目标是进行概念验证，以证明 Sr-U 作为一种工具的普遍应用，利用现代珊瑚和化石珊瑚来重建准确的海表温度记录。