Intermediate Water Records of Radiocarbon and Temperature from Deep-sea Corals since the LGM

自末次盛世以来深海珊瑚的放射性碳和温度的中间水记录

• 批准号: 1503129
• 负责人: Jess Adkins
• 金额: $ 25万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1503129&HistoricalAwards=false
• 关键词: Intermediate; Water; Records; Radiocarbon; Temperature

Intermediate waters in the modern ocean play an important role in global heat, salt, and nutrient transports, and have been at the heart of many explanations of the Last Glacial Maximum (LGM) and the deglaciation. Antarctic Bottom Water (AABW) is crucial in setting the pCO2 of the past but because it upwells and sinks at virtually the same temperature, it is not capable of driving significant poleward heat transport. Intermediate waters, on the other hand, contain a large component of subtropical waters that must cool before sinking to sub-thermocline depths. Here temperature contrasts can be large between source waters and sinking waters giving rise to globally significant heat transports.This research will monitor the radiocarbon content and temperature of intermediate waters from the LGM through the deglaciation in the North Atlantic, using existing deep sea coral samples collected from the New England Seamounts. The research team will measure the U-series ages, radiocarbon content, and clumped isotope composition of the fossil corals to constrain the characteristics of intermediate waters over the past ~25,000 years. This time series will help constrain the role of intermediate waters in glacial and deglacial climate change. Models have predicted, and a few studies have found, intermediate depth warming during Heinrich Stadial 1 (HS1), and the resulting data will be uniquely suited to investigate the rate and heat content of the intermediate circulation since the last glacial period. Funding supports the training of a PhD student, as well as outreach via public lectures and short videos on the links between the oceans and climate.

现代海洋中的中间沃茨在全球热、盐和营养物质的输送中起着重要作用，并且一直是末次冰期盛期（LGM）和冰消作用的许多解释的核心。南极底层水（AABW）对于设定过去的二氧化碳分压至关重要，但由于它在几乎相同的温度下上升和下降，因此它无法驱动显着的向极地热传输。另一方面，中层沃茨含有大量亚热带沃茨，这些海水在下沉到次温跃层深度之前必须冷却。在这里，温度差异可以是大的源沃茨和下沉沃茨引起全球显着的热transferation.This研究将监测放射性碳含量和温度的中间沃茨从末次冰期通过冰川消退在北大西洋，使用现有的深海珊瑚样本收集的新英格兰海山。研究小组将测量化石珊瑚的U系年龄、放射性碳含量和聚集同位素组成，以限制过去约25,000年来中间沃茨的特征。这一时间序列将有助于限制中间沃茨在冰期和冰消期气候变化中的作用。模型预测，一些研究已经发现，中间深度变暖海因里希Stadial 1（HS 1），由此产生的数据将是唯一适合调查的速度和热含量的中间循环自末次冰期。资金用于培训一名博士生，以及通过关于海洋与气候之间联系的公开讲座和短视频开展外联活动。