Investigating Antarctic Ice Sheet-Ocean-Carbon Cycle Interactions During the Last Deglaciation

研究末次冰消期期间南极冰盖-海洋-碳循环的相互作用

• 批准号: 2103032
• 负责人: Andreas Schmittner
• 金额: $ 77.23万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2103032&HistoricalAwards=false
• 关键词: Investigating; Antarctic; Ice; Sheet; Ocean

This project investigates Antarctic ice-ocean interactions of the last 20,000 years. The Antarctic ice sheet is an important component of Earth’s climate system, as it interacts with the atmosphere, the surrounding Southern Ocean, and the underlaying solid Earth. The ice sheet is also the largest potential contributor to future sea-level rise and a major uncertainty in climate projections. Climate change may trigger instabilities that may lead to fast and irreversible collapse of parts of the ice sheet. However, little is known about how interactions between the Antarctic ice sheet and the rest of the climate system affect its behavior, climate, and sea level, partly because most climate models currently do not have fully-interactive ice-sheet components. The project team will construct a numerical climate model that includes an interactive Antarctic ice sheet, improving computational infrastructure for research. The model code will be made freely available to the public on a code-sharing site. In addition, the team will synthesize paleoclimate data and compare these with model simulations. This model-data comparison will test three scientific hypotheses regarding past changes in deep-ocean circulation, ice sheet, carbon, and sea level. The project will contribute to a better understanding of ice-ocean interactions and past climate variability.The project will test ideas that ice-ocean interactions have been important for setting deep ocean circulation and carbon storage during the Last Glacial Maximum and subsequent deglaciation. The new model will consist of three existing and well-tested components: (1) an isotope-enabled climate-carbon cycle model of intermediate complexity; (2) a model of the combined Antarctic ice sheet, solid Earth, and sea level; and (3) an iceberg model. The coupling will include ocean-temperature effects on basal melting of ice shelves; freshwater fluxes from the ice sheet to the ocean; and calving, transport and melting of icebergs. Once constructed and optimized, the model will be applied to simulate the Last Glacial Maximum and subsequent deglaciation. Differences between model versions with full, partial, or no coupling will be used to investigate the effects of ice-ocean interactions on the Meridional Overturning Circulation, deep ocean carbon storage, and ice-sheet fluctuations. Paleoclimate data synthesis will include temperature, carbon and nitrogen isotopes, radiocarbon ages, protactinium-thorium ratios, neodymium isotopes, carbonate ion, dissolved oxygen, relative sea level, and terrestrial cosmogenic ages into one multi-proxy database with a consistent updated chronology. The project will support an early-career scientist, one graduate student, undergraduate students, and new and ongoing national and international collaborations. Outreach activities in collaboration with a local science museum will benefit rural communities in Oregon by improving their climate literacy.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.

这个项目调查了过去2万年南极冰海之间的相互作用。南极冰盖是地球气候系统的重要组成部分，因为它与大气、周围的南大洋和下面的固体地球相互作用。冰盖也是未来海平面上升的最大潜在因素，也是气候预测的主要不确定性因素。气候变化可能引发不稳定，从而导致部分冰盖迅速而不可逆转地崩塌。然而，关于南极冰盖与其他气候系统之间的相互作用如何影响其行为、气候和海平面，人们知之甚少，部分原因是目前大多数气候模式没有完全相互作用的冰盖成分。项目组将构建一个数值气候模型，其中包括一个相互作用的南极冰盖，以改善研究的计算基础设施。模型代码将在一个代码共享网站上免费提供给公众。此外，该小组将综合古气候数据，并将其与模型模拟结果进行比较。这种模式与数据的比较将检验关于深海环流、冰盖、碳和海平面过去变化的三个科学假设。该项目将有助于更好地了解冰海相互作用和过去的气候变化。该项目将验证冰-海相互作用在末次盛冰期和随后的冰川消退期间对确定深海环流和碳储存很重要的观点。新模型将由三个现有且经过充分测试的部分组成：(1)中等复杂程度的同位素驱动的气候-碳循环模型；(2)南极冰盖、固体地球和海平面的组合模式；(3)冰山模型。这种耦合将包括海洋温度对冰架基底融化的影响；从冰盖到海洋的淡水通量；以及冰山的崩解、移动和融化。一旦建立和优化，该模型将用于模拟末次盛冰期和随后的消冰。将利用完全、部分或不耦合模式版本之间的差异来研究冰-海相互作用对经向翻转环流、深海碳储量和冰盖波动的影响。古气候数据的综合将包括温度、碳和氮同位素、放射性碳年龄、镤钍比、钕同位素、碳酸盐离子、溶解氧、相对海平面和地球宇宙形成年龄，并将其纳入一个具有一致更新年表的多代理数据库。该项目将支持一名早期职业科学家，一名研究生，本科生，以及新的和正在进行的国内和国际合作。与当地科学博物馆合作的外展活动将通过提高他们的气候知识使俄勒冈州的农村社区受益。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

World Atlas of late Quaternary Foraminiferal Oxygen and Carbon Isotope Ratios (WA_Foraminiferal_Isotopes_2022)

晚第四纪有孔虫氧和碳同位素比世界地图集 (WA_Foraminiferal_Isotopes_2022)

• DOI: 10.1594/pangaea.936747
• 发表时间: 2021
• 期刊: PANGAEA - Data Publisher for Earth & Environmental Science
• 作者: Mulitza, Stefan;Bickert, Torsten;Bostock, Helen C;Chiessi, Cristiano Mazur;Donner, Barbara;Govin, Aline;Harada, Naomi;Huang, Enqing;Johnstone, Heather J;Kuhnert, Henning
• 通讯作者: Kuhnert, Henning