BRICS: Biology's Role In ocean Carbon Storage - a gap analysis

金砖国家：生物学在海洋碳储存中的作用——差距分析

• 批准号: NE/X00628X/1
• 负责人: Abigail McQuatters-Gollop
• 金额: $ 1.28万
• 依托单位: Plymouth University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX00628X%2F1
• 关键词: BRICS; Biology; Role; ocean; Carbon

The ocean is a large carbon reservoir which contains fifty times the amount of carbon in the atmosphere. Biological processes contribute to carbon storage in the ocean on climate-relevant timescales (hundreds to thousands of years). Marine phytoplankton, which are drifting microscopic plants, use sunlight and carbon dioxide in the upper ocean to form their biomass, also called organic matter. When phytoplankton die they sink into the ocean interior, moving organic carbon deeper in the water column; the deeper it goes the longer it will remain out of contact with the atmosphere. This process, often called the biological carbon pump, helps to regulate our climate and without biology in the ocean it has been shown that atmospheric carbon dioxide levels could be nearly double what they are today. In this project we will examine three ways in which biological processes influence global ocean carbon storage, and where knowledge gaps are hindering progress on predicting ocean carbon storage in the future. First, is understanding how the buffering capacity of seawater changes, driven by phytoplankton that produce chalk shells, which ultimately affects CO2 uptake. Second, is understanding the efficiency and variability of the primary production of organic matter by phytoplankton. Third, is understanding how much of this organic matter reaches the interior ocean, which tells us how much carbon has been respired during the transit from the upper ocean. Earth system models have differing simplistic representations of the biological carbon pump due to the computational costs of running global models far into the future. The suite of models that contribute to the Intergovernmental Panel on Climate Change (IPCC) reports do not agree on the magnitude or direction of change for ocean carbon storage under future climate scenarios. This means we have low confidence for our future projections, which is further impeded by a growing discrepancy between models and observations. This project will identify the gaps in our understanding and highlight model limitations for each of the three areas outlined above. We will achieve this by reviewing the current literature to identify key processes. We will assess the differences in how current climate models represent changes in the buffering capacity, primary production of organic matter and the amount of interior respiration, and how these differences may affect future ocean carbon storage projections. This will aid in identifying the observations that are needed to improve our grasp of the processes controlling the biological carbon pump, which will in turn allow for improved model representations and predictions. We aim to identify the priority processes that are significant contributors to biological carbon storage, have the potential to be widely measured to allow robust model representations, can be feasibly included into models, and are relevant over long timescales and globally. We will carry out an expert assessment by asking the international scientific community to rank which processes are the most significant for ocean carbon storage and climate feedbacks. Our analysis and the survey results will inform recommendations for future field programmes based on the tractability of observing key processes, and the likelihood of being able to include them in models.

海洋是一个巨大的碳库，其碳含量是大气中的50倍。生物过程在与气候相关的时间尺度上（数百至数千年）有助于海洋中的碳储存。海洋浮游植物是漂浮的微小植物，它们利用上层海洋中的阳光和二氧化碳来形成它们的生物量，也称为有机物质。当浮游植物死亡时，它们沉入海洋内部，将有机碳转移到水柱的更深处;越深，它与大气接触的时间就越长。这个过程，通常被称为生物碳泵，有助于调节我们的气候，如果没有海洋中的生物，大气中的二氧化碳水平可能会比现在高出近一倍。在这个项目中，我们将研究生物过程影响全球海洋碳储量的三种方式，以及知识差距阻碍未来预测海洋碳储量的进展。首先，是了解海水的缓冲能力如何变化，由产生白垩壳的浮游植物驱动，最终影响二氧化碳的吸收。第二，是了解浮游植物有机物质初级生产的效率和可变性。第三，是了解有多少有机物质到达海洋内部，这告诉我们有多少碳在从海洋上层运输的过程中被呼吸。地球系统模型对生物碳泵有不同的简化表示，这是因为运行全球模型的计算成本很高。为政府间气候变化专门委员会（IPCC）报告提供资料的一套模型并没有就未来气候情景下海洋碳储存变化的幅度或方向达成一致。这意味着我们对未来预测的信心很低，而模型和观测结果之间越来越大的差异进一步阻碍了这一点。这个项目将确定我们理解的差距，并强调上述三个领域中每个领域的模型限制。我们将通过回顾现有文献来确定关键过程来实现这一目标。我们将评估当前气候模型如何代表缓冲能力，有机物的初级生产和内部呼吸量的变化的差异，以及这些差异如何影响未来的海洋碳储量预测。这将有助于确定所需的观察结果，以提高我们对控制生物碳泵的过程的掌握，这反过来又将允许改进模型表示和预测。我们的目标是确定优先进程是生物碳储存的重要贡献者，有可能被广泛测量，以允许强大的模型表示，可以可行地包括到模型中，并在长期和全球范围内相关。我们将进行专家评估，请国际科学界对哪些过程对海洋碳储存和气候反馈最重要进行排名。我们的分析和调查结果将为今后根据观察关键过程的易处理性和将其纳入模型的可能性提出的实地方案提供信息。