Collaborative Research: Centennial-to-Millennial-Scale Climatic Fluctuations in Northeast Siberia during the Last Glacial Cycle

合作研究：末次冰期期间西伯利亚东北部百年至千年尺度的气候波动

• 批准号: 0117406
• 负责人: Patricia Anderson
• 金额: $ 44.54万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0117406&HistoricalAwards=false
• 关键词: Collaborative; Research; Centennial; Millennial; Scale

Studies of Earth's history show that climate is capable of changing rapidly (within a few years or decades) and dramatically (from glacial to interglacial conditions). The response of the Earth's ecosystems to such global-scale changes can be spatially complex. Paleoclimatic fluctuations are evident during the last glacial cycle (~12,000 and 110,000 years ago) when temperatures were generally cooler than present and were interrupted by 24 warm events during which temperature ranged from 15-20 degrees C. Understanding the mechanisms and timing of such environmental change is particularly important for the Arctic, a region particularly sensitive to climate variability. Historically, data from the Greenland ice sheet has been the foundation for paleoclimatic reconstruction for the region. Still lacking, however, is an understanding of how northern ecosystems have responded to changes in climate.This research will address this knowledge gap by providing the first continuous, high-resolution, multi-proxy record of paleovegetational and paleoclimatic change from the Arctic for the period ~22,000 to 50,000 years ago. A sediment core from Elikchan Lake in northeast Siberia will be recovered and analyzed for pollen and diatom remains as well as sediment geochemistry with sufficient temporal control to be compared to climate trends found in ice cores. These new data will be used to define the number, magnitude, and timing of climatic fluctuations to assess the similarities and differences in the climate histories between the eastern (North Atlantic) and western (northeast Siberia) Arctic. Specifically, the research will: 1) evaluate computer simulations of past temperature in northern Asia as related to climatic and oceanic changes in the North Atlantic region; 2) explore the role of Siberia in transmitting climatic fluctuations originating in the North Atlantic to the North Pacific; and 3) examine the range of ecosystem responses to various climatic conditions and the potential importance of biofeedback to the climate system (e.g., whether changes in the distribution of boreal forests, a major methane source, can affect levels of methane in the atmosphere).

对地球历史的研究表明，气候能够迅速（几年或几十年内）和剧烈（从冰川条件到间冰期条件）发生变化。 地球生态系统对这种全球范围的变化的反应在空间上可能是复杂的。 古气候波动在最后一个冰川周期（约 12,000 年前和 110,000 年前）期间非常明显，当时气温普遍低于现在，并被 24 次温暖事件打断，期间温度范围为 15-20 摄氏度。了解这种环境变化的机制和时间对于北极这一对气候变化特别敏感的地区尤为重要。 从历史上看，格陵兰冰盖的数据一直是该地区古气候重建的基础。 然而，我们仍然缺乏对北方生态系统如何应对气候变化的了解。这项研究将通过提供第一个连续、高分辨率、多代理记录，记录北极大约 22,000 至 50,000 年前的古植被和古气候变化，从而弥补这一知识差距。 西伯利亚东北部埃利克坎湖的沉积岩芯将被回收并分析花粉和硅藻遗骸以及沉积物地球化学，并进行足够的时间控制，以便与冰芯中发现的气候趋势进行比较。 这些新数据将用于定义气候波动的数量、幅度和时间，以评估北极东部（北大西洋）和西部（西伯利亚东北部）之间气候历史的异同。 具体来说，该研究将：1）评估与北大西洋地区气候和海洋变化相关的亚洲北部过去气温的计算机模拟； 2）探索西伯利亚在将源自北大西洋的气候波动传递到北太平洋方面的作用； 3) 研究生态系统对各种气候条件的反应范围以及生物反馈对气候系统的潜在重要性（例如，北方森林（主要甲烷来源）分布的变化是否会影响大气中甲烷的水平）。