Using Foraminiferal Nd Isotope Records to Test the Paradigm for Deglacial Atlantic Deepwater Variability

人们普遍认为，在最后一次冰川消退的寒冷事件(海因里希事件1和年轻的仙女座)期间，北大西洋北部向海洋内陆的深水出口显著减少。在最近关于这一主题的辩论的推动下，拟议的工作将根据过去约25,000年来钕同位素组成的良好记录，产生一种新的大西洋去冰川环流重建。这些记录将来自对西大西洋三个深度断面(北、热带、南)浮游有孔虫的分析。结合海底氧和碳同位素测量，钕同位素记录将被用来1)限制潜在的末端成员变化，2)确定大西洋上层、中部和深层的水团可变性，以及3)评估当前的去冰川深水可变性范例。这项工作将促进对与气候突变相关的海洋环流动力学的理解。该项目将支持伍兹霍尔海洋研究所一名资深科学家和一名职业生涯早期研究员之间的跨学科合作。本科生和高中生将接受实验室技术培训。此外，来自不同背景的10名高中生将通过国际学生联合会与当地一名高中教师合作进行为期一周的实习。

Deepwater export from the northern North Atlantic to the ocean interior is widely believed to have decreased significantly during cold events of the last deglaciation (Heinrich Event 1 and the Younger Dryas). Motivated by recent debate on the topic, the proposed work will produce a novel reconstruction of Atlantic deglacial circulation based on well-dated records of neodymium isotope composition spanning the last ~25,000 years. These records will be developed from analyses of planktonic foraminifera from three depth transects in the western Atlantic (north, tropical, south). In combination with benthic oxygen and carbon isotope measurements, the neodymium isotope records will be used to 1) constrain potential end-member changes, 2) determine water mass variability in the upper, mid-depth, and deep Atlantic, and 3) evaluate the current paradigm of deglacial deepwater variability. This work will advance the understanding of ocean circulation dynamics related to abrupt climate change. The project will support cross-disciplinary collaboration between a senior scientist and an early-career investigator at Woods Hole Oceanographic Institution. Undergraduate and high school students will be trained in laboratory techniques. In addition, ten high school students from diverse backgrounds will be engaged through a one-week internship facilitated by the PI in collaboration with a local high school teacher.