Collaborative Research: Diagnosing the Role of Ocean Eddies in Carbon Cycling from a High-resolution Data Assimilating Ocean Biogeochemical Model

尽管南大洋仅占全球海洋表面的20%，但它占海洋吸收的人为二氧化碳总量的40%，并且特别富含长寿的漩涡。这些漩涡，或者可以从太空观察到的大型海洋漩涡池，可以以尚未完全理解的方式改变二氧化碳的海气通量。测量海洋碳含量的自主平台的新观测表明，海洋碳通量存在显著的异质性，这可能与这些动态涡流特征有关。由于计算和时间的限制，海洋涡旋在大多数全球气候模拟中没有明确表示，限制了我们理解涡旋在海洋碳循环中所起作用的能力。这项研究将采用模拟和观测两种策略，探讨涡旋对南大洋海洋碳含量和海气二氧化碳通量的影响，研究结果将提高我们对海洋在碳循环和全球气候中的作用的认识。虽然这项工作将主要侧重于南大洋，但其结果将适用于全球。研究人员还将扩大南佛罗里达大学女孩海洋学夏令营的中学生对物理和化学海洋学的兴趣，通过海洋学的计算方法来增加现有的课程。该项目旨在量化中尺度涡动过程对南大洋海洋碳含量和海气二氧化碳（CO2）通量的影响。对于建模部分，研究人员将探索1/6度分辨率生物地球化学南大洋状态估计（B-SOSE）中涡旋，海洋碳含量和海气CO2通量之间的关系。他们的研究人员将按区域制作气旋和反气旋涡旋内碳含量和物理结构的高分辨率复合材料，量化这些涡旋对整体模拟海气CO2通量的影响，并诊断驱动这种影响的物理机制。 对于观测部分，调查人员将把通过卫星测高观测到的涡旋与海洋碳观测结果相匹配，并说明观测到的涡旋与海洋碳含量之间的关系，重点是南大洋冬季观测，因为那里的光照限制了生物过程，从而可以分离出物理过程的贡献。 这项工作还将为气候模式中更高的分辨率和更好的涡旋参数化、更多的中尺度海洋地球化学观测以及将卫星海面高度数据纳入CO2海气通量图的工作提供动力。每年夏天，PI在南佛罗里达大学海洋学女孩夏令营提供实验室课程，被NSF认可为“妇女和女孩的STEM示范项目”，重点是通过强调招募多样化的年轻女性群体来扩大参与。作为该项目的一部分，现有的基于Python笔记本的交互式Python编码实验室课程将增加一个以B-SOSE为主题的建模组件，这将扩大对物理和化学海洋学和数据科学的兴趣，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响进行评估来支持审查标准。

The Southern Ocean accounts for ~40% of the total ocean uptake of anthropogenic carbon dioxide despite covering only 20% of the global ocean surface, and is particularly rich in long-lived eddies. These eddies, or large ocean whirlpools which can be observed from space, can alter air-sea fluxes of carbon dioxide in ways that are not yet fully understood. New observations from autonomous platforms measuring ocean carbon content suggest that there is significant heterogeneity in ocean carbon fluxes which can be linked to these dynamic eddy features. Due to computational and time limitations, ocean eddies are not explicitly represented in most global climate simulations, limiting our ability to understand the role eddies play in the ocean carbon cycle. This study will explore the impact of eddies on ocean carbon content and air-sea carbon dioxide fluxes in the Southern Ocean using both simulated- and observation-based strategies and the findings will improve our understanding of the ocean’s role in the carbon cycle and in global climate. While this work will primarily be focused on the Southern Ocean, the results will be globally applicable. The researchers will also broaden interest in physical and chemical oceanography among middle school-age girls in the University of South Florida’s Oceanography Camp for Girls by augmenting existing lessons with computational methods in oceanography. This project aims to quantify the impacts of mesoscale eddy processes on ocean carbon content and air-sea carbon dioxide (CO2) fluxes in the Southern Ocean. For the modeling component, the investigators will explore relationships between eddies, ocean carbon content, and air-sea CO2 fluxes within the 1/6-degree resolution Biogeochemical Southern Ocean State Estimate (B-SOSE). They investigators will produce high-resolution composites of the carbon content and physical structure within both cyclonic and anticyclonic eddies by region, quantify the influence of these eddies on the overall simulated air-sea CO2 flux, and diagnose the physical mechanisms driving this influence. For the observational component, the investigators will match eddies observed via satellite altimetry to ocean carbon observations and characterize observed relationships between eddies and ocean carbon content with a focus on Southern Ocean winter observations where light limits biological processes, allowing isolation of the contribution of physical processes. This work will also provide motivation for higher resolution and better eddy parameterizations in climate models, more mesoscale biogeochemical observations, and integration of satellite sea surface height data into efforts to map air-sea fluxes of CO2. Each summer, the PI delivers a lab lesson at the University of South Florida Oceanography Camp for Girls, recognized by NSF as a “Model STEM Program for Women and Girls” focused on broadening participation by placing emphasis on recruiting a diverse group of young women. As part of this project, the existing interactive Jupyter Notebook-based Python coding Lab lesson will be augmented with a B-SOSE-themed modeling component, which will broaden interest in physical and chemical oceanography and data science, and expose campers to computational methods in oceanography.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.