Eddy Effects on the Biological Carbon Pump

海洋在全球碳循环中发挥着关键作用，目前每年吸收约四分之一的二氧化碳排放。这些碳通过物理和生物过程从表层沃茨转移到深海。第一种是通过物理运动，或俯冲，水从表面到深海。这被称为溶解度泵。第二种机制，称为生物泵，从浮游植物开始，通过海洋表面的光合作用吸收碳。这些物质的一小部分随后沉入更深的海洋。在第三种机制中，游泳生物可以主动地将物质从表面运输到更深的沃茨。目前的挑战是了解所有这三个过程如何在较小的海洋斑块中相互作用，并将这些知识纳入海洋和气候模型。该项目将使用高分辨率海洋模型研究这些过程，并与现实世界的观测结果进行比较。该项目将支持早期职业女性科学家、一名研究生和本科实习生。该项目还将有助于夏季质疑基础有效的科学教学（QUEST）实践计划的小学和中学教师，并在普林斯顿大学教授的课程，由首席研究员使用她的研究开发的模型教学生如何批判性地思考海洋和气候模型。观测结果表明，海洋碳泵是由涡流，锋和细丝调制，但这些无处不在的海洋功能对全球碳输出的综合影响是有限的。拟议的工作将利用高分辨率生物物理模型和现有的观测结果，以促进对小规模生物和物理泵的机械理解。该项目将添加到以前的工作，研究小规模的俯冲（从PI和其他团体），并研究如何涡驱动的生态系统斑块和营养相互作用影响的俯冲和下沉泵（目标1）。该项目还将为迁移泵带来新的机械见解（目标2）。具体而言，如何涡流效应调制浮游动物丰度，放牧和昼夜迁移幅度之间的相互作用。该项目不包括季节性规模的迁徙、较大的中层动物和一些生物因素（如体型）的影响。然而，它将为未来在更现实的情况下探索这种泵的工作提供急需的基线，例如解释高分辨率的现场测量和分析全球模型结果。该项目还将首次提供一份关于海洋碳泵在整个季节周期内对区域框架内小规模动态的反应的综合报告（目标3）。该项目将使用理想化的双环流模型，但对比区域将提供一个广阔的视角，与全球海洋碳泵的理解及其如何应对气候变化有关。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The oceans play a critical role in the global carbon cycle, currently absorbing approximately one-quarter of the carbon dioxide emissions each year. This carbon is moved from the surface waters to the deep ocean by physical and biological processes. The first is by physical movement, or subduction, of water from the surface to the deep ocean. This is referred to as the solubility pump. The second mechanism, called the biological pump, starts with phytoplankton that take up carbon through photosynthesis in the surface ocean. A small fraction of this material then sinks to the deeper ocean. In a third mechanism, swimming organisms can actively transport material from surface to deeper waters. A current challenge is to understand how all three of these processes interact in smaller patches of the oceans, and to incorporate this knowledge into ocean and climate models. This project will examine these processes using a high-resolution ocean model and comparisons to real-world observations. The project will support early career female scientists, a graduate student, and undergraduate interns. The project will also contribute to the summer Questioning Underlies Effective Science Teaching (QUEST) hands-on program for elementary and middle school teachers, and to a course taught at Princeton University by the lead investigator that uses models developed in her research to teach students how to think critically about ocean and climate models. Observations show that the ocean carbon pump is modulated by eddies, fronts and filaments, but the integrated effect of these ubiquitous ocean features on the global carbon export is poorly constrained. The proposed effort will harness a high-resolution bio-physical model and existing observations to advance the mechanistic understanding of the biological and physical pumps occurring at small-scale. This project will add to previous works that studied small-scale subduction (from the PI and other groups) and examine how eddy-driven ecosystem patchiness and trophic interactions influence the subduction and sinking pumps (Objective 1). The project will also bring new mechanistic insights in the migration pump (Objective 2). Specifically, how eddy effects modulate the interplay between mesozooplankton abundance, grazing and diurnal migration amplitude. This project excludes the effects of migrations on seasonal scales, larger mesopelagic animals, and some biological factors (e.g. body-size). Yet it will provide a much-needed baseline for future work to explore this pump in more realistic cases, such as the interpretation of high resolution in-situ measurements and the analysis of global model results. This project will also provide, for the first time, a synthesis of the ocean carbon pumps response to small-scale dynamics in a regional framework over a full seasonal cycle (Objective 3). This project will use an idealized double gyre model but the contrasted regions will give a broad perspective, relevant to the understanding of the global ocean carbon pump and how it might respond to climate change.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.