Collaborative Research: P2C2--isotope-enabled TRAnsient Climate Evolution of the last 21,000 years (iTRACE21)----Understanding Deglacial Climate/Isotope Changes Using iCESM

合作研究：P2C2——过去21,000年同位素驱动的瞬态气候演化（iTRACE21）——利用iCESM了解冰消期气候/同位素变化

• 批准号: 1810682
• 负责人: Zhengyu Liu
• 金额: $ 13.5万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1810682&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; isotope; enabled

This research investigates the mechanisms of climate changes during the last deglaciation (21,000 to 11,000 years ago) using a state-of-the-art isotope-enabled Earth System Model (ESM). The major scientific questions to be addressed in this project are: (1) What are the relationships between the isotopic composition of water and climate changes over the globe? (2) How does the climate system respond to changing climate forcings of the last deglaciation, and what is the contribution from each forcing: insolation, atmospheric greenhouse gases, continental ice sheets, and meltwater? The simulations will allow the study of the continuous evolution and abrupt changes of climate from interannual to orbital time scales. The type of transient simulation marks a transformative breakthrough in model-data comparison, allowing for direct data and model time series comparisons, and will have a significant impact on future paleoclimate studies using both models and observations. The proposed simulations will have a ground breaking impact on research in the paleoclimate community, providing model data for a number of other community projects. It will lay a foundation for a systematic test of future generations of ESMs with coupled cryosphere and biogeochemical models. Specifically, the new version of NCAR's community ESM (CESM), enabled with water isotope tracers, will be run in fully-coupled mode for the period 21,000 to 11,000 years ago. The main simulation will be forced by prescribed changes in insolation, atmospheric greenhouse gas concentrations, continental ice sheets, sea level, and meltwater, while sensitivity simulations will investigate the effect of the different forcings separately. This simulation will be run at a higher resolution (2 degrees in the atmosphere and 1 degree in the ocean) than the previous generation transient model run with CCSM3 (3 degrees). Furthermore, stable water isotope tracers have been included in the atmosphere, land-surface, ocean, and sea-ice models and will be tested first for the Last Glacial Maximum (LGM, 21,000 years ago) and present climate time slices before being run in transient mode for the last deglaciation. One central task of the proposed transient simulations is to explore a new paradigm of model-data comparison in close collaboration with the data community, focusing on direct time series comparisons of isotopes. The simulation of isotope time series will improve paleoclimate model-data comparison significantly, because it will reduce the uncertainties arising from both the inference of isotopes and the absolute chronology of the proxy records. The project will provide the basis for graduate research for students from the University of Wisconsin and Oregon State University.

这项研究研究了使用最先进的同位素地球系统模型（ESM）调查了最后一次脱气期间气候变化的机制（21,000至11，000年前）。该项目要解决的主要科学问题是：（1）水的同​​位素组成与全球气候变化之间有什么关系？ （2）气候系统如何应对上一次脱气的气候强迫的反应，每种强迫的贡献是什么：日光浴，大气温室气体，大陆冰盖和融化？这些模拟将允许研究从多年来到轨道时间尺度的持续进化和突然变化。瞬态模拟的类型标志着模型数据比较的变革性突破，允许进行直接数据和模型时间序列比较，并将使用模型和观察结果对未来的古气候研究产生重大影响。拟议的模拟将对古气候社区的研究产生破裂的影响，为许多其他社区项目提供模型数据。它将为子孙后代的ESMS进行耦合的冰冻圈和生物地球化学模型的系统测试奠定基础。具体来说，由水同位素示踪剂启用的NCAR社区ESM（CESM）的新版本将在21,000至11，000年前以完全耦合的模式运行。主要模拟将受到规定的日期变化，大气温室气体浓度，大陆冰盖，海平面和融化水的规定变化，而灵敏度模拟将分别研究不同强迫的效果。该模拟将比上一代瞬态模型以CCSM3（3度）运行的上一代瞬态模型以更高的分辨率（大气中的2度和1度）进行。此外，稳定的水同位素示踪剂已包含在大气，地表，海洋和海冰模型中，并将首先测试最后一次冰川最大值（LGM，21，000年前）和当前的气候切片，然后在瞬态模式下以瞬态的方式运行。建议的瞬态模拟的一项核心任务是与数据界密切合作探索模型数据比较的新范式，重点介绍同位素的直接时间序列比较。同位素时间序列的模拟将显着改善古气候模型数据比较，因为它将减少同位素的推断和代理记录的绝对年代学引起的不确定性。该项目将为威斯康星大学和俄勒冈州立大学的学生提供研究生研究的基础。