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

尽管南大洋只覆盖了全球海洋表面的20%，但却占了海洋人为二氧化碳吸收总量的约40%，而且南大洋拥有特别丰富的长寿命漩涡。这些可以从太空中观察到的漩涡或大型海洋漩涡可以以尚未完全了解的方式改变二氧化碳的海气通量。自主平台测量海洋碳含量的新观测结果表明，海洋碳通量存在显著的异质性，这可能与这些动态涡动特征有关。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，这限制了我们理解涡旋在海洋碳循环中所起作用的能力。这项研究将利用模拟和观测两种策略，探索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理解。虽然这项工作将主要集中在南大洋，但其结果将适用于全球。研究人员还将通过增加现有的海洋学计算方法课程，扩大南佛罗里达大学海洋学女生夏令营中学女生对物理和化学海洋学的兴趣。该项目旨在量化中尺度涡旋过程对南大洋海洋碳含量和海气二氧化碳通量的影响。对于建模组件，研究人员将在1/6度分辨率的生物地球化学南大洋状态估计（B-SOSE）中探索涡流、海洋碳含量和海气二氧化碳通量之间的关系。他们的研究人员将按区域制作气旋和反气旋涡旋内的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空气-海洋二氧化碳通量的影响，并诊断驱动这种影响的物理机制。对于观测部分，研究人员将把通过卫星测高观测到的涡流与海洋碳观测相匹配，并将观测到的涡流与海洋碳含量之间的关系特征化，重点放在南大洋冬季观测上，那里的光照限制了生物过程，从而可以隔离物理过程的贡献。这项工作还将为在气候模式中实现更高分辨率和更好的涡流参数化、更多的中尺度生物地球化学观测以及将卫星海面高度数据整合到二氧化碳的海气通量图中提供动力。每年夏天，PI都会在南佛罗里达大学海洋学女孩营开设一门实验课，该营地被美国国家科学基金会认定为“妇女和女孩示范STEM项目”，重点是通过招募不同群体的年轻女性来扩大参与范围。作为这个项目的一部分，现有的基于Jupyter notebook的交互式Python编程实验室课程将增加一个以b -海洋学为主题的建模组件，这将扩大人们对物理、化学海洋学和数据科学的兴趣，并使营员接触到海洋学中的计算方法。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 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.