Towards Establishing Density Structure of the Antarctic Circumpolar Current during the Last Glacial Maximum

知识价值：pi提出了一项试点研究，以探讨利用底栖有孔虫的氧同位素建立末次极大期（LGM）南极环极流（ACC）结构的可行性。虽然这样的测量在ACC以北有很多，但在ACC以南只有一个公布的LGM底栖生物氧同位素测量。pi将分析ACC以南的一系列沉积物岩心，以确定他们是否能够识别具有适当地层和足够底栖有孔虫的岩心，以建立LGM底栖生物氧同位素剖面。他们还将研究基于现有数据和动态约束在ACC上重建LGM密度对比的可能性。这项工作的结果可以为海洋-大气系统的重要组成部分ACC的动力学和生物地球化学行为提供强有力的约束。更广泛的影响：这项工作可以帮助填补目前对大气风、海洋涡流和密度结构之间相互作用的动力学理解的空白，这是气候动力学界的一个活跃研究领域。pi将为来自代表性不足群体的本科生提供研究经验。

Intellectual Merit: The PIs propose a pilot study to investigate the feasibility of establishing the structure of the Antarctic Circumpolar Current (ACC) during the Last Glacial Maximum (LGM) using oxygen isotopes in benthic foraminifera. While such measurements are plentiful north of the ACC, there is only one published LGM benthic oxygen isotope measurement south of the ACC. The PIs will analyze a series of sediment cores south of the ACC to determine if they can identify cores with the appropriate stratigraphy and sufficient benthic foraminifera to establish a profile of LGM benthic oxygen isotopes. They will also investigate the possibility of reconstructing the LGM density contrast across the ACC based on existing data and dynamical constraints. The outcomes of this work could provide strong constraints on both the dynamical and biogeochemical behavior of the ACC, an important component of the ocean-atmosphere system.Broader impacts: This work could help fill a gap in current dynamical understanding of the interactions between atmospheric winds, ocean eddies and the density structure, which is an area of active research in the climate dynamics community. The PIs will provide research experience for an undergraduate student from an under-represented group.