Understanding Climate-Biogeochemical Feedbacks During the Last Glacial Cycle: A Systematic Modeling and Paleo-Data Synthesis Approach

这位研究人员和他的同事将使用系统建模方法来理清千年和冰期-间冰期气候变异性的控制强迫功能和放大机制。这项研究的总体科学目标是更好地理解从末次冰期向全新世过渡过程中物理和生物地球化学过程的动态作用。具体地说，研究人员将使用中等复杂性的全球三维大气-海洋-海冰动力学模型以及植被模型和海洋碳循环模型来开发涵盖末次冰川终止和整个全新世时期的瞬变模拟。模型的模拟结果将在幅度、时间和季节性方面与公开可用的海洋和陆地替代档案进行直接比较，这些档案涉及来自沉积物岩芯、冰芯、洞穴和湖面指示的数据。研究战略旨在探索以下科学问题：全球碳循环如何响应轨道驱动的气候变化？轨道引起的南半球西风带变化在推动大气二氧化碳变化方面有多重要？碳循环响应在加速冰期-间冰期转变中起什么作用？碳循环在调节最后一次冰期期间千年尺度的气候变异性方面起什么作用？这项研究将有助于提高更广泛的科学界对地球辐射敏感性的理解，这可能会对未来气候的理解产生影响。这项研究战略将特别有助于区分不同的气候强迫因素，并有助于进一步努力解释来自最后一次冰川时期的古替代数据。该研究项目还将使一名博士后学者和一名研究生能够接受古气候建模和数据分析方面的培训。

The researcher, and colleagues, will use a systematic modeling approach to disentangle the controlling forcing functions, as well as amplifying mechanisms, of millennial and glacial-interglacial climate variability. The general scientific goal of the research is an improved understanding of the dynamic role of physical and biogeochemical processes during the transition from the last glacial into the Holocene.Specifically, the researcher will use a global three-dimensional dynamical atmosphere-ocean-sea ice model of intermediate complexity coupled to a vegetation model and a marine carbon cycle model to develop transient simulations covering the last glacial termination and the entire Holocene period. The model simulation output will be directly compared, in terms of amplitude, timing and seasonality, with publicly available marine, as well as terrestrial, proxy archives involving data from sediment cores, ice cores, speleothems, and lake-level indices.The research strategy is designed to pursue the following scientific questions:How does the global carbon cycle respond to orbitally-driven climate variations? How important are orbitally-induced changes of the southern hemispheric westerlies in driving atmospheric carbon dioxide variations? What role does the carbon cycle response play in accelerating glacial-interglacial transitions?What role does the carbon cycle play in modulating millennial-scale climate variability during the last glacial period? The research will help to improve the wider science community''s understanding of the radiative sensitivity of Earth with possible implications for the understanding of future climate. The research strategy will specifically help differentiate, regionally, between various climate forcing factors and aid further efforts to interpret paleo-proxy data from the last glacial period. The research project will also enable the training of a postdoctoral scholar and a graduate student in paleoclimate modeling and data analyses.