Collaborative Research: Investigating Southern Ocean Sea Surface Temperatures and Freshening during the Late Pliocene and Pleistocene along the Antarctic Margin

合作研究：调查上新世晚期和更新世沿南极边缘的南大洋海面温度和新鲜度

• 批准号: 2313121
• 负责人: Melissa Berke
• 金额: $ 34.56万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2027-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2313121&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigating; Southern; Ocean

Non-technical: As Antarctica’s ice sheets melt, freshwater enters the ocean, which can increase sea ice cover adjacent to the ice sheet. Sea ice formation changes the density of sea water thus regulating the circulation of water throughout the global ocean. Sea ice expansion may also slow down the processes driving ice sheet melt. This research will examine the relationship between surface ocean cooling and ocean freshening from geological records recovered adjacent, as well as farther seaward from the ice margin. These records will provide key information regarding the role in sea ice expansion during the process of deglaciation. The geological records span time intervals when climate conditions were similar to predicted future warming scenarios. Therefore, these new records will provide perspective on what the consequences of an ice sheet melting and surface ocean freshening might be in the near-term (100 years) and long-term (100-years) future.Technical Description: Ocean warming and Antarctic ice mass loss over the last few decades has resulted in surface freshening in the Ross Sea sector of the Southern Ocean. Surface ocean freshening is linked to sea ice expansion, which has an important role in regulating global ocean circulation and is hypothesized to be a negative climate feedback slowing ice retreat. The forcings and feedbacks involved in Southern Ocean warming, ice shelf melt, surface ocean freshening, sea ice growth, and deep water formation remain poorly understood due to the short-term nature of instrumental records. The objective of this research program is to: (1) generate multi-proxy Plio-Pleistocene sea surface temperature and meltwater records in ice-proximal and ice-marginal settings during deglacial and interglacial intervals from archived sediment cores of ANDRILL AND-1B as well as International Ocean Discovery Program (IODP) U1524, and (2) examine the external forcing mechanisms and orbital pacing of sea surface temperature and meltwater variability during the Plio-Pleistocene. Results from this project aim to better understand ocean-ice sheet driven dynamics under varying climate scenarios of the most recent geological past.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.

非技术性：随着南极洲冰盖的融化，淡水进入海洋，这可能会增加冰盖附近的海冰覆盖。海冰的形成改变了海水的密度，从而调节了整个全球海洋的水循环。海冰的膨胀也可能减缓推动冰盖融化的过程。这项研究将从邻近和远离冰缘的地质记录中考察表层海洋冷却和海洋清新之间的关系。这些记录将提供有关冰川消融过程中海冰扩张所起作用的关键信息。地质记录跨越了气候条件与预测的未来变暖情景相似的时间间隔。因此，这些新的记录将提供关于冰盖融化和表层海洋清新在近期(100年)和长期(100年)未来可能产生的后果的视角。技术描述：过去几十年来，海洋变暖和南极冰块减少导致了南大洋罗斯海部分的表层清新。表层海洋清新与海冰扩张有关，海冰扩张在调节全球海洋环流方面具有重要作用，并被假设为减缓冰川消退的负气候反馈。由于仪器记录的短期性质，南大洋变暖、冰架融化、表层海洋淡化、海冰增长和深水形成所涉及的强迫和反馈仍然知之甚少。这项研究的目标是：(1)从ANDRILL和-1B以及国际海洋发现计划(IODP)U1524的沉积物岩芯中生成去冰期和间冰期期间近冰期和冰缘环境中的多代理上更新世海表面温度和融水记录，以及(2)研究更新世期间海表面温度和融水变化的外部强迫机制和轨道调步。该项目的成果旨在更好地了解在最近地质历史的不同气候情景下的海洋冰盖驱动的动力学。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。