Comparison of climate and carbon cycle dynamics during late Quaternary interglacials using a spectrum of climate system models, ice-core and terrestrial archives (COIN)

第四纪间冰期在气候、植被覆盖和大气CO2方面表现出不同幅度和不同模式的变化。该项目将利用一系列地球系统模式对间冰期环境进行数值模拟的结果与新生成的植被和气候数据以及陆地和海洋档案的综合数据结合起来。古气候数据用于确定模式模拟能够再现间冰期气候的哪些方面，以及已测试的强迫机制（温室气体、冰盖、植被反馈、日照的进动和倾角分量）中哪些驱动了过去暖期的气候变化。通过分析一个粗分辨率EMIC CLIMBER2-LPJ的千年模拟，并与高分辨率模式CCSM 3的时间片模拟进行比较，研究了土地覆盖与气候之间反馈的重要性。该项目的最后阶段的主要重点是对中布朗什事件早期间冰期的数据模型比较。为此，我们将根据贝加尔湖的长花粉记录、水越湖的花粉和硅藻记录以及现有的早、晚间冰期（100-650 ka）陆地和海洋气候记录，进行气候模拟的后处理和建立新的重建。数据模型比较是根据七个关键假设进行的，使我们能够对第四纪间冰期进行集中的定量评估，其总体目标是提高我们对气候系统的理解，以便更好地约束用于未来气候预测的地球系统模型。

Quaternary interglacials show varying amplitudes and different patterns of changes in climate, vege-tation cover, and atmospheric CO2. This project combines the results of numerical simulations of interglacial environments using a spectrum of Earth-system models with newly generated vegetation and climate data and data syntheses from terrestrial and marine archives. The paleoclimate data are used to determine which aspects of the interglacial climate the model simulations are able to repro-duce and which of the tested forcing mechanisms (greenhouse gases, ice-sheets, vegetation feed-backs, precession and obliquity components of insolation) have driven climate change of past warm intervals. The importance of feedbacks between land cover and climate is being addressed by ana-lysing multi-millennial simulations of a coarse-resolution EMIC, CLIMBER2-LPJ, and compared with time-slice simulations of the high-resolution model CCSM 3. The main focus of this final phase of the project is on data-model comparison for early interglacials across the Mid-Brunhes Event. To this end we will engage in post-processing of climate simulations and establishment of new reconstructions based on long pollen records from Lake Baikal, pollen and diatom records from Lake Suigetsu and a synthesis of existing terrestrial and marine climate records of early and late interglacials (100-650 ka). The data-model comparison is structured along seven key hypotheses allowing us to carry out a focused quantitative assessment of Quaternary interglacials with the overarching aim to improve our understanding of the climate system so as to better constrain the Earth-system models used for future climate projections.