Toward a mechanistic model of the ocean biological carbon pump

海洋生物碳泵的机械模型

• 批准号: 1803308
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1803308
• 关键词: Toward; mechanistic; model; ocean; biological

Photosynthesis by phytoplankton at the surface of the ocean absorb CO2 from the atmosphere to produce organic matter. At the end of their life cycle these marine organisms aggregate into large, rapidly sinking particles. This sinking organic matter is in turn fed on by bacteria and zooplankton, respiring CO2 that can remain dissolved in the deep ocean for thousands of years. This set of processes, collectively known as the "biological carbon pump" (BCP), is a major pathway by which carbon is transported from the atmosphere to the deep sea. Understanding the complex processes that control the efficiency of the BCP and hence the relative partitioning of carbon between the ocean and atmosphere and, ultimately, climate, is one of the leading problems in oceanography and climate science, and the subject of the NERC-funded COMICS (Controls over Ocean Mesopelagic Interior Carbon Storage) project supporting this studentship. Unfortunately, important as it is, current models of the BCP embedded within global climate models do not have a mechanistic representation of the BCP. They are thus largely incapable of responding to environmental changes and cannot be used to investigate how the BCP will evolve in the future or how it may have operated in the past. The primary objective of this project is to obtain a mechanistic understanding of the BCP and it's response to environmental conditions. To achieve this goal, a global model that represents the processes through which marine particles stick together or break apart will be developed. Starting with the growth of phytoplankton at the surface the model will explicitly consider the main processes affecting the sinking of organic particles through the ocean. This model of particles and biogeochemistry will interact with ocean circulation as simulated by models such as UKESM.Specifically, the goal is to take a stochastic approach to modeling the dynamics of marine particles in which the interaction between individual particles, biology and ocean circulation are explicitly simulated. Such a Lagrangian approach has not previously been attempted in 3-d because of its computational expense. We plan to address this by exploiting novel computational hardware such as programmable Graphics Processing Units GPUs to achieve computational speedup of the model. The student will not only lead the development of the model-acquiring training and skills in marine biogeochemistry, oceanography and high performance computing and numerical modeling-but also perform experiments to mechanistically explore the BCP's response to climate change, especially changes in circulation, atmospheric CO2 and ocean chemistry. The student will actively collaborate with COMICS team members at the National Oceanography Centre, Southampton, and other observational and modeling groups in the US, Germany and France.

海洋表面的浮游植物进行光合作用，从大气中吸收二氧化碳，产生有机物质。在它们生命周期的末期，这些海洋生物聚集成巨大的、迅速下沉的颗粒。这些下沉的有机物反过来又被细菌和浮游动物喂养，呼吸二氧化碳，这些二氧化碳可以在深海中溶解数千年。这一系列过程统称为"生物碳泵"（BCP），是碳从大气层输送到深海的主要途径。了解控制BCP效率的复杂过程，以及海洋和大气之间碳的相对分配，最终是气候，是海洋学和气候科学的主要问题之一，也是NERC资助的COMICS（海洋中层内部碳储存控制）项目的主题。不幸的是，尽管BCP很重要，但目前嵌入全球气候模型的BCP模型并没有BCP的机械表示。因此，它们在很大程度上无法对环境变化做出反应，也无法用于调查BCP在未来将如何演变或它在过去可能如何运作。这个项目的主要目标是获得一个机械的了解BCP和它的环境条件的反应。为实现这一目标，将开发一个全球模型，展示海洋颗粒粘在一起或分解的过程。从浮游植物在海面的生长开始，该模型将明确考虑影响有机颗粒通过海洋下沉的主要过程。该粒子和海洋地球化学模型将与UKESM等模型模拟的海洋环流相互作用。具体而言，目标是采用随机方法模拟海洋粒子的动力学，其中明确模拟单个粒子，生物和海洋环流之间的相互作用。这种拉格朗日方法以前没有尝试在3-d，因为它的计算费用。我们计划通过开发新的计算硬件（如可编程图形处理单元GPU）来解决这个问题，以实现模型的计算加速。学生不仅将领导模型的开发-获得海洋地球化学，海洋学和高性能计算和数值模拟方面的培训和技能-而且还将进行实验，以机械地探索BCP对气候变化的响应，特别是循环，大气CO2和海洋化学的变化。学生将积极与南安普顿国家海洋学中心的COMICS团队成员以及美国、德国和法国的其他观测和建模小组合作。