Collaborative Research: Millennial Scale Fluctuations of Dry Valleys Lakes: Implications for Regional Climate Variability and the Interhemispheric (a)Synchrony of Climate Change

合作研究：干谷湖泊的千年尺度波动：对区域气候变率和半球间气候变化同步性的影响

• 批准号: 0124049
• 负责人: Glenn Berger
• 金额: --
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0124049&HistoricalAwards=false
• 关键词: Collaborative; Research; Millennial; Scale; Fluctuations

0124049BergerThis award supports a project to add to the understanding of what drives glacial cycles. Most researchers agree that Milankovitch seasonal forcing paces the ice ages but how these insolation changes are leveraged into abrupt global climate change remains unknown. A current popular view is that the climate of Antarctica and the Southern Ocean leads that of the rest of the world by a couple thousand years at Termination I and by even greater margins during previous terminations. This project will integrate the geomorphological record of glacial history with a series of cores taken from the lake bottoms in the Dry Valleys of the McMurdo Sound region of Antarctica. Using a modified Livingstone corer, transects of long cores will be obtained from Lakes Fryxell, Bonney, Joyce, and Vanda. A multiparameter approach will be employed which is designed to extract the greatest possible amount of former water-level, glaciological, and paleoenvironmental data from Dry Valleys lakes. Estimates of hydrologic changes will come from different proxies, including grain size, stratigraphy, evaporite mineralogy, stable isotope and trace element chemistry, and diatom assemblage analysis. The chronology, necessary to integrate the cores with the geomorphological record, as well as for comparisons with Antarctic ice-core and glacial records, will come from Uranium-Thorium, Uranium-Helium, and Carbon-14 dating of carbonates, as well as luminescence sediment dating. Evaluation of the link between lake-level and climate will come from hydrological and energy-balance modelling. Combination of the more continuous lake-core sequences with the spatially extensive geomorphological record will result in an integrated Antarctic lake-level and paleoclimate dataset that extends back at least 30,000 years. This record will be compared to Dry Valleys glacier records and to the Antarctic ice cores to address questions of regional climate variability, and then to other Southern Hemisphere and Northern Hemisphere records to assess interhemispheric synchrony or asynchrony of climate change.

0124049Berger该奖项支持一个项目，以加深对冰川周期驱动因素的理解。 大多数研究人员都认为米兰科维奇季节性强迫会加速冰河时代的进程，但这些日照变化如何导致全球气候突然变化仍然未知。目前流行的观点是，南极洲和南大洋的气候在第一终止时比世界其他地区领先几千年，在之前的终止中领先的幅度更大。 该项目将把冰川历史的地貌记录与取自南极洲麦克默多海峡地区干谷湖底的一系列岩芯整合起来。使用改进的利文斯通取芯器，将从弗里克塞尔湖、邦尼湖、乔伊斯湖和万达湖获得长岩心横断面。 将采用多参数方法，旨在从干谷湖泊中提取尽可能多的前水位、冰川和古环境数据。水文变化的估计将来自不同的代理，包括粒度、地层学、蒸发岩矿物学、稳定同位素和微量元素化学以及硅藻组合分析。 将岩心与地貌记录相结合以及与南极冰芯和冰川记录进行比较所必需的年代学将来自碳酸盐的铀-钍、铀-氦和碳-14测年以及发光沉积物测年。 对湖泊水位与气候之间联系的评估将来自水文和能量平衡模型。 将更连续的湖芯序列与空间广泛的地貌记录相结合，将产生一个可追溯到至少 30,000 年前的综合南极湖泊水位和古气候数据集。该记录将与干谷冰川记录和南极冰芯进行比较，以解决区域气候变化的问题，然后与其他南半球和北半球记录进行比较，以评估气候变化的半球间同步或异步。