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特性（所谓的代理）来揭示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采用多种代理方法，使用广泛的代理，这使我的团队能够区分当地和全球气候信号，并在气候系统的不同组成部分之间建立阶段（即因果）关系。 我小组的研究有两个主要的长期目标：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，以及建立对氮的透彻了解 过去海洋氮库存变化的同位素证据。赤道太平洋是 地球的气候系统，并被认为是过去全球气候的煽动者、放大器和调解者 年际到千年时间尺度上的变化。例如，厄尔尼诺南方涛动（ENSO） 主导着当今热带太平洋的年际变化，远程连接影响气候 世界范围内，因此有人提出，过去的全球气候变化可能是通过 热带太平洋平均状态的“类 ENSO”变化。我的跨学科研究 对过去海洋氮循环和库存变化的氮同位素证据的系统分析将揭示一个首要问题：生物地球化学变化（例如硝酸盐循环）是否是数千年时间尺度上大气二氧化碳海洋封存变化的主要原因。 这种对海洋和大气的空间和时间变化的全方位以及地球气候系统各个组成部分之间相互关系的多代理重建是验证当前气候模型和建立必须衡量潜在人为影响的“背景”状态所必需的。