Paleobiogeochemistry of marine sediments

海洋沉积物的古生物地球化学

• 批准号: 288200-2011
• 负责人: Kienast, Markus
• 金额: $ 2.4万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571365
• 关键词: Paleobiogeochemistry; marine; sediments

The sediments on the sea floor are natural archives of past climate and ocean variability. I propose to unravel the information preserved in these records by determining the contents of various organic remains and mineral and chemical properties, so- called proxies. The key to my novel contributions to paleo-oceanographic research is a multi-proxy approach, using a wide range of proxies, which enables my group to differentiate between local and global climate signals, and to establish phasing (i.e. causal) relationships between different components of the climate system. Research in my group has two primary long-term goals: to understand more fully the importance of the tropical Pacific Ocean in past global climate change, and to establish a thorough understanding of nitrogen isotope evidence for past changes in the oceanic nitrogen inventory. The equatorial Pacific is fundamental to Earth's climate system, and has been purported to be instigator, amplifier and mediator of past global climate change on inter-annual to multi-millennial time-scales. For example, the El Niño Southern Oscillation (ENSO) dominates the inter-annual variability of the tropical Pacific today, with tele-connections affecting climate worldwide, and it has thus been proposed that past global climate change could have been modulated by "ENSO-like" variations in the mean state of the tropical Pacific. My cross-disciplinary research into the systematics of nitrogen isotope evidence for past changes in the oceanic N cycling and inventory will shed light on the over-arching question whether or not biogeochemical changes, such as nitrate cycling are the primary cause for changes in the oceanic sequestration of atmospheric CO2 on multi-millennial time-scales. This kind of multi-proxy reconstruction of the full range of the spatial and temporal variability of the ocean and atmosphere and the interrelation between various components of Earth's climate system is required for validating current climate models and for establishing a 'background' state against which potential anthropogenic influences will have to be measured.

海底的沉积物是过去气候和海洋变化的自然档案。我建议通过确定各种有机残留物的含量以及矿物和化学性质，即所谓的替代物，来解开这些记录中保存的信息。我对古海洋学研究的新贡献的关键是多代理方法，使用广泛的代理，使我的团队能够区分本地和全球气候信号，并在气候系统的不同组成部分之间建立阶段（即因果关系）关系。 我小组的研究有两个主要长期目标：更全面地了解热带太平洋在过去全球气候变化中的重要性，以及对氮有透彻的了解 海洋氮存量过去变化的同位素证据。赤道太平洋是 地球的气候系统，并一直声称是煽动者，放大器和调解人过去的全球气候 从跨年度到多千年时间尺度的变化。厄尔尼诺南方涛动（ENSO） 主导着热带太平洋的年际变化，与远程连接影响气候 因此，有人提出，过去的全球气候变化可能是由 热带太平洋平均状态的“ENSO样”变化。我的跨学科研究 海洋氮循环和库存过去变化的氮同位素证据的系统学将揭示过度的问题是否地球化学变化，如硝酸盐循环的主要原因，在海洋封存的大气CO2在多千年的时间尺度上的变化。 这种多代理重建的海洋和大气的空间和时间变化的全方位和地球的气候系统的各个组成部分之间的相互关系是需要验证当前的气候模式，并建立一个'背景'的状态，对潜在的人为影响将不得不被测量。