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表层水域转移到深海。第一种是水从表面向深海的物理移动或俯冲。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，它们通过光合作用在表层海洋中吸收碳。然后，这种材料的一小部分就会沉入更深的海洋。在第三种机制中，游动生物可以主动地将物质从表面输送到更深的水域。目前的一个挑战是了解所有这三个过程如何在较小的海洋区域相互作用，并将这些知识纳入海洋和气候模型。这个项目将使用高分辨率的海洋模型并与真实世界的观测进行比较来研究这些过程。该项目将支持职业生涯早期的女科学家、研究生和本科生实习生。该项目还将为中小学教师的暑期有效科学教学(QUEST)实践项目以及普林斯顿大学的一门课程做出贡献，该课程由首席研究员教授，该课程使用她研究中开发的模型来教会学生如何批判性地思考海洋和气候模型。观测结果表明，海洋碳泵受到涡旋、锋面和细丝的调制，但这些无处不在的海洋特征对全球碳输出的综合影响很难受到约束。拟议的工作将利用高分辨率的生物物理模型和现有的观察结果，以促进对小规模生物和物理泵的机械理解。该项目将补充以前研究小规模俯冲的工作(来自PI和其他小组)，并研究涡流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)。该项目还将为移民泵带来新的机械学见解(目标2)。具体地说，涡旋效应如何调节中浮游动物丰度、放牧和每日迁徙幅度之间的相互作用。该项目不包括迁徙对季节尺度、较大的中上层动物和一些生物因素(如体型)的影响。然而，它将为今后在更现实的情况下探索这一泵的工作提供亟需的基线，例如高分辨率现场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对整个季节周期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回旋模型，但对比地区将提供一个广阔的视角，与理解全球海洋碳泵以及它可能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智力优势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.