Collaborative Research: Quantifying regional variability in abyssal mixing from Ship-based Chi-pod measurements

合作研究：通过船基 Chi-pod 测量量化深海混合的区域变化

• 批准号: 2023397
• 负责人: Jonathan Nash
• 金额: $ 9.46万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2023397&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantifying; regional; variability

Despite its large climatic importance, the dynamics controlling the strength of the meridional overturning circulation remain poorly understood due to limited observations. In particular, the heterogeneity of deep mixing and the cause of spatial variability is still poorly understood due to a lack of direct observations. This project will conduct a global analysis of full ocean-depth microstructure measurements to explore the magnitude, patterns, and physical processes underlying turbulent mixing rates across different physical and dynamical regimes. The work will capitalize on over 1000 new microstructure full-depth profiles collected on nine GO-SHIP repeat hydrography cruises, including zonal and meridional sections across the Indian, Pacific and Atlantic oceans. The work will build on existing robust processing techniques for this novel type of microstructure data, making all results available to the oceanographic research community.This project will use the new GO-SHIP chi-pod data set, which offers the largest comprehensive dataset of deep turbulence measurements to date, to advance understanding of deep ocean mixing. The project will evaluate the application of fine scale parameterizations in the deep ocean compared to microstructure; explore the magnitude, patterns, and physical processes underlying observed turbulent mixing rates across different physical and dynamical regimes; and calculate mean basin and global rates of diffusivity from measurements of mixing from the chi-pods and finescale parameterizations. The analysis will lead to a better understanding of the limits and applicability of widely used finescale parameterizations which are based on assumptions of turbulence driven by internal wave-wave interactions. The results will improve understanding of the processes underlying observed patterns of mixing. Finally, the project will investigate the role of processes that set deep turbulent mixing rates for which the finescale technique does not apply, including internal-wave mean flow interaction and double diffusion.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.

尽管其对气候具有重要意义，但由于观测有限，控制经向翻转环流强度的动力学仍然知之甚少。特别是，由于缺乏直接观察，深度混合的异质性和空间变异的原因仍然知之甚少。该项目将对全海洋深度微观结构测量进行全球分析，以探索不同物理和动力学状态下湍流混合速率的幅度、模式和物理过程。这项工作将利用在 9 次 GO-SHIP 重复水文学巡航中收集的 1000 多个新的微观结构全深度剖面，包括印度洋、太平洋和大西洋的纬向和经向剖面。这项工作将建立在针对这种新型微观结构数据的现有稳健处理技术的基础上，将所有结果提供给海洋学研究界。该项目将使用新的 GO-SHIP chi-pod 数据集，该数据集提供了最大的深海综合数据集迄今为止的湍流测量，以增进对深海混合的理解。该项目将评估深海精细尺度参数化与微观结构的应用；探索不同物理和动力学状态下观察到的湍流混合速率的大小、模式和物理过程；并根据 Chi-pod 的混合测量和精细参数化计算平均盆地和全局扩散率。该分析将有助于更好地理解广泛使用的细尺度参数化的局限性和适用性，这些参数化基于内波-波相互作用驱动的湍流假设。结果将增进对观察到的混合模式背后的过程的理解。最后，该项目将研究设定深度湍流混合速率的过程的作用，其中精细尺度技术不适用，包括内波平均流相互作用和双扩散。该奖项反映了 NSF 的法定使命，并被认为值得通过以下方式获得支持：使用基金会的智力价值和更广泛的影响审查标准进行评估。

项目成果

Abyssal Heat Budget in the Southwest Pacific Basin

西南太平洋盆地的深海热量收支

• DOI: 10.1175/jpo-d-21-0045.1
• 发表时间: 2021
• 期刊: Journal of Physical Oceanography
• 影响因子: 3.5
• 作者: Lele, Ratnaksha;Purkey, Sarah G.;Nash, Jonathan D.;MacKinnon, Jennifer A.;Thurnherr, Andreas M.;Whalen, Caitlin B.;Mecking, Sabine;Voet, Gunnar;Talley, Lynne D.
• 通讯作者: Talley, Lynne D.