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

从北大西洋北部到海洋内部的深水出口被广泛认为在最后一次冰川消退的寒冷事件（海因里希事件1和新仙女木期）期间显著减少。受最近关于这一主题的争论的推动，这项拟议的工作将基于过去~25,000年的钕同位素组成的准确年代记录，产生一种新的大西洋去冰环流重建。这些记录将从对西大西洋（北、热带、南）三个深度样带浮游有孔虫的分析中得到发展。结合底栖生物氧和碳同位素测量，钕同位素记录将用于1)约束潜在的端元变化，2)确定大西洋上部、中部和深处的水质量变异性，以及3)评估当前的去冰深水变异性范式。这项工作将促进对与气候突变有关的海洋环流动力学的认识。该项目将支持伍兹霍尔海洋研究所一位资深科学家和一位早期职业研究者之间的跨学科合作。本科生和高中生将接受实验室技术培训。此外，PI将与当地一名高中教师合作，安排10名来自不同背景的高中生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.