Collaborative Research: Carbon Isotope and geotracer-enabled simulation of the Transient Climate Evolution of the Deglacial Ocean (C-iTRACE-O)

合作研究：碳同位素和地理示踪剂支持的冰下海洋瞬态气候演化模拟（C-iTRACE-O）

• 批准号: 1600080
• 负责人: Zhengyu Liu
• 金额: $ 25.8万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2018-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1600080&HistoricalAwards=false
• 关键词: Collaborative; Research; Carbon; Isotope; geotracer

Global climate has undergone large changes during the last deglaciation (21,000 to 11,000 years ago), with a warming of ~3.5°C globally, a sea level rise of ~80 m, and the disappearance of the large continental ice sheets. The large magnitude of the signals and the availability of extensive paleoclimate data make this period an excellent target for investigating the mechanisms underlying climate change and for the validation of state-of-the-art Earth System Models (ESMs). However, up until now model simulations could not be directly compared with the paleoclimate records, as the models did not simulate the geochemical tracers ("proxies") on which the reconstructions are based. To address this issue and provide insights into several long-standing scientific questions about the evolution of the ocean's overturning circulation during the deglaciation, this project will perform the first transient ocean simulation of the deglaciation with the newly developed isotope modules in the ocean model of the Community Earth System Model (CESM1), allowing for direct model-data comparison of multiple marine paleo proxies. This project will contribute to STEM workforce development by supporting the training of two graduate students in climate modeling and model-data comparisons and by providing project leadership experience for an early career female scientist, who will work in close collaboration with U.S. and international colleagues. Results from this project will be used in undergraduate and graduate classes at the University of Colorado at Boulder and the University of Wisconsin-Madison and will be incorporated into public outreach through a project website and through general-audience talks. The output of the simulation (called C-iTRACE-O) will be made freely available though the Earth System Grid gateway, allowing the entire paleoclimate community to use it for their research. The simulation will also be contributed to the Paleoclimate Model Intercomparison Project transient deglacial working group, allowing for an evaluation of the CESM C-iTRACE compared to the deglacial simulations from other ESMs.By directly simulating oceanic carbon-isotopes (d13C and D14C), Neodymium (eNd), and Protactinium/Thorium (231Pa/230Th) for the deglaciation and by carrying out sensitivity experiments to investigate the physical mechanisms causing the changing isotopic and geotracer distributions in the transient simulation, it will be possible to address some long-standing scientific questions through direct comparisons to observations and by evaluating tracer-circulation relationships in the model itself, such as:- What was the source and routing of the low-radiocarbon CO2 released during the Mystery Interval? - What is the implication of the d13C evolution in the Atlantic for the deep ocean circulation during the last deglaciation and how much of the d13C change was caused by nutrient- and air-sea gas exchange effects versus circulation changes? - Why is the deglacial evolution of Antarctic Intermediate Water controversial among proxies, notably in eNd and carbon isotopes? - How does 231Pa/ 230Th represent the deglacial evolution of North Atlantic deep circulation and Southern Ocean upwelling?

全球气候在最后一次脱气中经历了约80 m的大量，并且大陆冰盖的消失是大量的迹象。但是，由于模型没有模拟地球化学示踪剂的基础，因此无法直接将系统模型的验证（ESMS）与古气候记录进行比较解决此问题，并在社区模型社区（CESM1）Roxies的社区中脱落的几个长期的科学问题。在气候建模和数据的研究生。通过项目网站，将纳入公共范围，虽然通用审计会议（称为C-itrace-o）将获得地球系统Gateway EIR研究。为古气候模型对抗项目的跨性脱气工作r对脱胶的评估r对脱胶的toms.直接模拟海洋碳 - 同位素，新近山（End）和protactinium/thorium（231pa/230th）（231pa/230）出现敏感性实验典型机制，导致传输中的托管和地理架分布发生变化，它将通过直接比较观察到观察结果以及对模型中的关系的直接比较，例如： - 诸如：间隔？第230位代表北方深循环和南部上升流的冰纹演变？