Marine sediments and seafloor nutrient cycling in a changing Arctic

不断变化的北极的海洋沉积物和海底养分循环

• 批准号: 1942899
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1942899
• 关键词: Marine; sediments; seafloor; nutrient; cycling

Sediments are key components of all marine ecosystems. In marine sediments, a dynamic interplay of biogeochemical processes is fuelled by the deposition of particulate material, as well as the diffusion of dissolved species from the overlying water column. This interplay transforms a substantial part of the deposited material and, thus, recycles nutrients, dissolved inorganic carbon, and alkalinity back into the water column. These benthic recycling fluxes can exert an important influence on pelagic primary production and ocean acidification.Past research has indicated that the coupling between benthic and pelagic processes is particularly intense on Arctic shelves. The Arctic Ocean is subject to strong seasonal to long-term fluctuations in, among other factors, temperature and sea-ice extent and, so, deposition fluxes, bottom water conditions and bioturbation. Despite its importance for marine ecosystems, the benthic response to such strong seasonal and long-term fluctuations in the Arctic remains underexplored.The aim of this project is to identify the most important controls on the timing and magnitude of benthic biogeochemical processes and fluxes under fluctuating environmental conditions in the Arctic Ocean on both seasonal and climate relevant timescales. The student will use Reaction-Transport Models (RTMs) to explore this challenge by conducting comprehensive sensitivity studies and by carrying out fully transient simulations and model inter-comparisons. The student will also be able to generate their own geochemical records using samples collected in the field from Arctic and other high-latitude field expeditions, in order to carry out a data-model comparison study.

沉积物是所有海洋生态系统的关键组成部分。在海洋沉积物中，生物地球化学过程的动态相互作用是由颗粒物质的沉积以及来自上覆水柱的溶解物质的扩散所推动的。这种相互作用转化了沉积物质的很大一部分，从而使营养物质、溶解的无机碳和碱度循环回到水柱中。这些底栖生物循环通量对远洋初级生产和海洋酸化具有重要影响。过去的研究表明，在北极大陆架上，底栖生物和远洋生物过程之间的耦合尤为强烈。除其他因素外，北冰洋受温度和海冰范围以及沉积通量、底水条件和生物扰动等因素的强烈季节性和长期波动的影响。尽管底栖生物对海洋生态系统很重要，但它们对北极这种强烈的季节性和长期波动的反应仍未得到充分探索。这个项目的目的是在季节和与气候有关的时间尺度上，确定北冰洋波动环境条件下底栖生物地球化学过程和通量的时间和幅度的最重要控制措施。学生将使用反应-输运模型（RTMs）来探索这一挑战，通过进行全面的敏感性研究，并通过进行全瞬态模拟和模型间比较。学生还将能够使用从北极和其他高纬度野外考察中收集的样品生成自己的地球化学记录，以便进行数据模型比较研究。