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: 2305428
• 负责人: Ana Ravelo
• 金额: $ 18.11万
• 依托单位: University of California-Santa Cruz
• 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=2305428&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关键要素。它是南极圆极电流的所在地，这是地球上最快的海洋电流。作为强大的碳汇，它代表了针对人类引起的温室气体排放的某些影响的重要盾牌。但是，推动南大洋变异性的过程仍然很广为人知。该项目将在过去200万年中调查南太平洋在气候系统中的作用。它将使用在COIDES分辨率的最近进行的钻探探险中回收的沉积物核心。该项目将产生表面海洋状况的记录，以告知我们对海洋占用二氧化碳并将其存储在深海中的能力的理解。地球科学是STEM领域的参与程度不足的少数民族的参与程度最少。该项目将使用队列学生计划积极促进多样性并扩大参与。在心理学教授的指导下，该项目将创造一个环境，从而通过多样性来增强参与，学习和创新。这种队列方法的一个目标是将地球科学教育从基于守门的风格转变为对来自多样性背景的人们的邀请和支持的风格。气候科学界对地球长期气候进化的理解主要来自北半球气候记录。鉴于南大洋在全球气候系统中的核心作用及其与南极冰盖的邻近性，南半球的数据差距严重抑制了我们在重大碎屑过渡过程中了解海洋 - 大冰冰纸动力学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这些过程的理解特别有价值，因为太平洋包含了迄今为止南洋最大的表面积和体积分数，因此具有最大的深海碳存储能力。该项目提议在过去的200万年中生成高分辨率的气候代理时间序列序列，并使用在探险383期间恢复的新沉积物核心在整个中期过渡（MPT）中进行重点。这些长期记录将探索气候/碳动态的变化，通过重新组建尘埃输入，并将这些记录与这些记录相结合，并将这些记录与这些记录相结合，并将这些记录与这些记录相结合，并将这些记录与这些记录相结合，并将这些记录与这些记录进行汇总，并将这些记录与这些记录相结合，并将这些记录与这些记录相结合，并将这些记录与这些记录进行了’温度，水质量结构和循环。该项目从美国三个机构的专业知识中的借鉴将在三个钻机（U1539，U1540和U1541）的三个完整的生物学和地球化学示踪剂中生产出前所未有的套件。