Development and application of geochemical tracers for paleo and modern oceanography

古和现代海洋地球化学示踪剂的开发与应用

• 批准号: 312376-2007
• 负责人: François, Roger
• 金额: $ 2.26万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=365659
• 关键词: Development; application; geochemical; tracers; paleo

The rise in anthropogenic CO2 may alter future climate and we must improve our predictive capabilities to decide on optimal societal responses. The ocean plays a critical role in regulating Earth's climate by controlling atmospheric CO2 and by redistributing incoming solar heat. The distribution of two natural radioisotopes (230Th and 231Pa) in seawater provides important information on particle dynamics, carbon fluxes and deep-water circulation in the modern ocean, which can be used to better quantify oceanic processes important for climate change. In addition, the incorporation of these isotopes in the sedimentary record provides a means of assessing the temporal evolution of these oceanic processes in relation to past climate changes and provides the needed temporal context to distinguish between climatic trends induced by anthropogenic activities and recurring natural cycles.I will measure detailed water column profiles of 230Th and 231Pa dissolved in seawater and associated with marine particles in the northeastern and equatorial Pacific which will complement on-going work in the northwestern Atlantic. These profiles will bring quantitative information on ventilation (Atlantic) and upwelling (Pacific) rates of deep water, and on the factors controlling the sinking rates of marine particles and the sequestration of carbon into the deep sea.This information will be placed in a larger temporal context using the sedimentary record of 230Th and 231Pa to further document changes in carbon flux and deep-water circulation associated with climatic shifts during the late Quaternary and the Holocene. Atlantic sediments provide insights into past changes in deep water formation and their role in triggering abrupt climate changes (work funded by CFCAS). I will complement this study by integrating the 230Th, 231Pa, and foraminifera Mg/Ca in a multi-PIs, multiproxy study of past changes in the circulation and productivity of the Pacific Ocean.

人为二氧化碳的增加可能会改变未来的气候，我们必须提高我们的预测能力，以决定最佳的社会反应。海洋通过控制大气二氧化碳和重新分布传入的太阳热来调节地球气候至关重要。海水中两个天然放射性同位素（230th和231pa）的分布提供了有关现代海洋中粒子动态，碳通量和深水循环的重要信息，可用于更好地量化对气候变化重要的海洋过程。此外，这些同位素在沉积记录中的融合提供了一种方法，可以评估这些海洋过程与过去气候变化有关的时间演变，并提供了所需的时间环境，以区分人为活动和反复出现的自然循环引起的气候趋势。太平洋将补充西北大西洋的正在进行的工作。这些概况将带来有关通风（大西洋）和深水上升速度的定量信息，以及控制海洋颗粒的下沉速率的因素以及将碳固并到深海中的沉没速率，这些信息将在230和231pa的沉积物中与较大的循环变化相关的较大的时间上下文，并在较大的时间上放置碳液体的变化，并在碳液体中的变化中变化，并将其置于碳液化状态下，并将其固定在碳液中的变化中。全新世。大西洋沉积物为深水形成的过去变化及其在触发突然的气候变化（由CFCAS资助）中的作用提供了见解。我将通过整合了对太平洋过去循环和生产力的过去变化的多智能研究中的第230、231pa和有孔虫mg/ca来补充这项研究。