Eddy Effects on the Biological Carbon Pump

海洋在全球碳循环中发挥着关键作用，目前每年吸收大约四分之一的二氧化碳排放量。这些碳通过物理和生物过程从地表水转移到深海。第一种是物理运动，即水从地表向深海的俯冲。这被称为溶解度泵。第二种机制被称为生物泵，从浮游植物开始，浮游植物通过光合作用吸收海洋表面的碳。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，游动的生物可以主动地将物质从水面运输到更深的水域。目前的挑战是了解这三种过程如何在较小的海洋区域内相互作用，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并与现实世界的观测结果进行比较来研究这些过程。该项目将支持早期职业女性科学家、一名研究生和本科生实习生。该项目还将对面向中小学教师的暑期有效科学教学（QUEST）实践项目做出贡献，并对普林斯顿大学（Princeton University）的一门课程做出贡献，该课程由首席研究员使用她在研究中开发的模型来教授学生如何批判性地思考海洋和气候模型。观测表明，海洋碳泵受到涡旋、锋面和细丝的调节，但这些普遍存在的海洋特征对全球碳输出的综合影响很少受到约束。提议的努力将利用高分辨率生物物理模型和现有的观察来推进对小规模发生的生物和物理泵的机制理解。该项目将补充先前研究小规模俯冲（来自PI和其他小组）的工作，并研究涡旋驱动的生态系统斑块和营养相互作用如何影响俯冲和下沉泵（目标1）。该项目还将为迁移泵带来新的机理见解（目标2）。特别是，涡旋效应如何调节中浮游动物丰度、放牧和日迁移幅度之间的相互作用。这个项目排除了季节性迁徙、较大的中上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，例如高分辨率原位测量的解释和全球模型结果的分析。该项目还将首次综合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（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，与了解全球海洋碳泵及其如何应对气候变化有关。该奖项反映了美国国家科学基金会的法定使命，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.