Deciphering the Subantarctic South Pacific Ocean’s Role in Pleistocene Climate Evolution with IODP Expedition 383 Sediments

利用 IODP 383 号探险队沉积物解读亚南极南太平洋在更新世气候演化中的作用

• 批准号: 2305426
• 负责人: Gisela Winckler
• 金额: $ 64.28万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-15 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2305426&HistoricalAwards=false
• 关键词: Deciphering; Subantarctic; South; Pacific; Ocean

The Southern Ocean is a key element of the global climate system. It is home to the Antarctic Circumpolar Current, the fastest ocean current on Earth. As a strong carbon sink, it represents an important shield against some of the effects of human-caused greenhouse gas emissions. However, the processes driving the Southern Ocean’s variability are still poorly known. This project will investigate the role of the South Pacific in the climate system over the past 2 million years. It will do so using sediment cores recovered during a recent drilling expedition on the Joides Resolution. The project will generate records of surface ocean conditions that can inform our understanding of the capacity of the ocean to take up carbon dioxide and store it in the deep ocean. The geosciences are the STEM field with the least participation from underrepresented minorities. The project will use a cohort student program to actively promote diversity and broadened participation. Under the guidance of a psychology professor, the project will create an environment that enhances engagement, learning and innovation through diversity. A goal of this cohort approach is to shift geoscience education from a style based on gatekeeping to one that that is inviting and supportive of people from diverse backgrounds.The climate science community’s understanding of Earth’s long-term climate evolution predominantly comes from Northern Hemisphere climate records. Given the central role of the Southern Ocean in the global climate system and its proximity to the Antarctic Ice Sheet, the Southern Hemisphere data gap severely inhibits our ability to understand global changes in ocean-atmosphere-ice sheet dynamics and carbon cycling during major climatic transitions. Records from the South Pacific are especially valuable to improve our understanding of these processes, because the Pacific contains by far the largest surface area and volume fraction of the Southern Ocean and therefore holds the largest capacity for carbon storage in the deep ocean. This project proposes to generate high-resolution climate proxy time series over the past 2 million years with emphasis across the Mid-Pleistocene Transition (MPT) using new sediment cores recovered during Expedition 383. These long records will explore changes in climate/carbon dynamics at the ocean surface by reconstructing dust input, nutrient utilization, and export production and these records will be synthesized and interpreted with collaborators’ records of sea surface temperature, water mass structure and circulation. Drawing from expertise across three US institutions, the project will produce an unprecedented suite of complementary biological and geochemical tracers at three drill sites (U1539, U1540, and U1541) in the Subantarctic Pacific.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

南大洋是全球气候系统的一个关键要素，它是地球上最快的洋流南极绕极流的所在地，它是一个强大的碳汇，是抵御人类造成的温室效应的重要屏障。然而，人们对南大洋变化的过程仍知之甚少，该项目将利用最近钻探中发现的沉积物岩心来研究南太平洋在过去 200 万年中的作用。乔德斯河探险该项目将生成表层海洋状况的记录，帮助我们了解海洋吸收二氧化碳并将其储存在深海的能力。地球科学是少数族裔项目参与最少的领域。将利用队列学生计划积极促进多样性和扩大参与，该项目将创造一个通过多样性增强参与、学习和创新的环境。一种基于把关的风格鉴于南大洋在全球气候系统中的核心作用及其与海洋的邻近性，气候科学界对地球长期气候演变的理解主要来自北半球的气候记录。南极冰盖、南半球的数据差距严重限制了我们了解主要气候转变期间海洋-大气-冰盖动态和碳循环的全球变化的能力。来自南太平洋的记录对于提高我们对气候变化的了解特别有价值。这些过程，因为太平洋拥有迄今为止南大洋最大的表面积和体积分数，因此拥有深海最大的碳储存能力，该项目建议生成过去2年的高分辨率气候代理时间序列。百万年，重点是使用第 383 次远征期间发现的新沉积岩芯，重点关注中更新世过渡期 (MPT)。这些长期记录将通过重建尘埃输入、养分利用和出口生产来探索海洋表面气候/碳动态的变化，以及这些记录该项目将利用合作者的海面温度、水团结构和循环记录进行综合和解释，利用三个美国机构的专业知识，在三个钻探地点（U1539、U1540、U1540）生产一套前所未有的互补生物和地球化学示踪剂。和 U1541）在亚南极太平洋。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。