Bloom and bust: seasonal cycles of phytoplankton and carbon flux

繁荣与萧条：浮游植物和碳通量的季节性周期

• 批准号: 2910180
• 金额: --
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2910180
• 关键词: Bloom; bust; seasonal; cycles; phytoplankton

CO2 taken up from the atmosphere by biological processes in the ocean is transferred into the deep ocean mostly in the form of sinking particles. Without this "biological carbon pump", atmospheric CO2 would be 50% higher than it already is. Despite its importance, our understanding is limited by scarce ship-board observations, especially how particulate organic carbon (POC) fluxes vary over days to seasons. However, a growing network of underwater robots are opening the door for high-resolution observations of these sinking particles. Gliders are unmanned autonomous vehicles that make measurements over weeks to months, including optical backscatter data which can be used to estimate POC fluxes. At PAP, one of the UK's long-term observing sites, we have collected data from multiple glider missions, including in collaboration with colleagues at NASA. These data will allow important unresolved questions to be addressed: How do fluxes vary seasonally in relation to phytoplankton blooms? How episodic are the fluxes? What are the implications for characterizing global-scale organic carbon fluxes? (Bol et al., 2018; Henson et al., 2015) Filling this gap will allow better predictions of how this important planetary carbon flux is linked to productivity and how it responds to variability in the environment. The project will initially use data obtained from gliders during past missions at PAP, such as OSMOSIS [1] and EXPORTS to determine the temporal patterns in POC fluxes, their attenuation with depth, and how this relates to phytoplankton blooms. Glider-derived optical backscatter data will be transformed into estimates of POC concentration and flux, using protocols established by co-supervisor Briggs [2]. Different metrics to characterise the fraction of POC flux reaching the mesopelagic zone will be calculated. Your initial analysis will focus on establishing the temporal patterns of phytoplankton blooms, flux and attenuation, before moving on to assessing how interannual variability in physical conditions may alter the relationship between primary production and fluxes. Depending on your interests, subsequent work may include exploiting additional autonomous technologies to study particular processes, e.g. particle fragmentation [2], other locations in more detail, satellite data to broaden the study to larger spatial and temporal scales, or using global biogeochemical models to explore the mechanisms and patterns of variability in POC fluxes. If interested, you may participate in the planning and deployment of more autonomous platforms for 2 upcoming funded projects (Bio-carbon and ReBELS), both aimed at better quantifying the carbon sequestration pathways in subpolar regions.

海洋生物过程从大气中吸收的二氧化碳主要以下沉颗粒的形式转移到深海。如果没有这种“生物碳泵”，大气中的二氧化碳将比现在高出50%。尽管它的重要性，我们的理解是有限的稀缺船上观察，特别是如何颗粒有机碳（POC）通量变化的日子到季节。然而，不断增长的水下机器人网络正在为这些下沉粒子的高分辨率观测打开大门。滑翔机是一种无人驾驶的自动飞行器，可以在数周到数月内进行测量，包括光学后向散射数据，这些数据可用于估计POC通量。在英国的长期观测站之一PAP，我们收集了多个滑翔机任务的数据，包括与NASA的同事合作。这些数据将使重要的未解决的问题得到解决：如何通量随季节变化的浮游植物水华？这些变化有多偶发？描述全球尺度有机碳通量的含义是什么？(Bol例如，2018; Henson等人，填补这一空白将有助于更好地预测这一重要的行星碳通量如何与生产力联系起来，以及它如何对环境的变化做出反应。该项目最初将使用过去在PAP执行任务期间从滑翔机获得的数据，例如OSMOSIS [1]和EXPORTS，以确定POC通量的时间模式，其随深度的衰减，以及这与浮游植物水华的关系。滑翔机衍生的光学后向散射数据将转换为POC浓度和通量的估计值，使用共同主管Briggs建立的协议[2]。将计算不同的指标来衡量到达中层的POC通量的比例。您的初步分析将集中在建立浮游植物水华，通量和衰减的时间模式，然后再评估物理条件的年际变化如何改变初级生产力和通量之间的关系。根据您的兴趣，后续工作可能包括利用其他自主技术来研究特定过程，例如颗粒破碎[2]，更详细的其他位置，卫星数据将研究扩展到更大的空间和时间尺度，或使用全球地球化学模型来探索POC通量的变化机制和模式。如果有兴趣，您可以参与规划和部署更多的自主平台，用于2个即将到来的资助项目（生物碳和ReBELS），这两个项目都旨在更好地量化次极地地区的碳封存途径。