Evaluation of Eemian and Holocene Climate Variability: Synthesis of marine archives with climate modelling (HolEem)

该项目的主要目标是调查通过综合全球气候模式和全球海洋表面海洋温度记录得出的埃米亚和全新世期间温度变化的时空模式。我们将探索现有的、重新编辑的和新收集的海洋古温度数据的全球分布，并将其与用于评估未来气候变化的最新大气环流模型的瞬变实验结果进行比较。古数据收集和建模工作的目的将是调查全新世中后期(过去6000年)和伊米亚(现在之前的12.5万年)期间区域上非常不同的时间气候模式。特别强调最后2-3千年，努力补充对上一个千年的研究。通过对古数据记录和模式结果中的时空变异性进行高级统计分析，将在数据中识别自然气候变率模式及其幅度，并将其与模式实验中追踪到的气候变率进行比较。将最新的全新世气候模拟延伸到下个世纪，利用未来温室气体排放的情景，可以帮助评估受自然和人为“强迫”影响的未来气候变化。统计分析将从不同的替代时间序列(烯酮和镁/钙)中提取气候现象，并阐述过去两个间冰期的共同变率和遥相关。其目的是揭示内部变异性和自然强迫因素，如地球轨道参数，对气候变异性和气候趋势区域异质性的影响。将研究大尺度海洋环流的变化以及温盐环流变化与气候低频变化之间的反馈机制。

The major objective of the project is to investigate the spatio-temporal pattern of temperature changes during the Eemian and Holocene as derived from integrations with a comprehensive global climate model and marine surface ocean temperature records on a global scale. We will explore the worldwide distribution of existing, reedited, and newly collected marine paleotemperature data and compare it with results from transient experiments with a state-of-theart general circulation model used in the assessment of future climate change. The paleodata collection and the modelling efforts will aim to investigate the regionally very different temporal climate patterns during the middle to late Holocene (the last 6,000 years) and the Eemian (125,000 years before present). Special emphasis is placed on the last 2-3 thousand years, striving to complement a study of the last millennium. With advanced statistical analysis of spatial and temporal variability in the paleodata records and in the model results, natural climate variability modes and their amplitude will be identified in the data and compared with the climate variability tracked down in the model experiments. The extension of the Latest Holocene climate simulations into the next centuries, using scenarios for future greenhouse gas emission, can help to assess 4 future climatic change influenced by natural and anthropogenic “forcing”. The statistical analyses will extract climate phenomena from different proxy time series (Alkenones and Mg/Ca) and elaborate common variability and teleconnections for the last two interglacial periods. The aim is to unravel the influence of internal variability and natural forcing factors, like e.g. parameters of the Earth's orbit, on climate variability and regional heterogeneity in climate trends. The variations in the large-scale ocean circulation and feedback mechanisms between thermohaline circulation changes and low-frequency variations of climate will be investigated.