Collaborative Research: Physical and biological controls on ocean carbon and oxygen uptake in the western North Pacific

合作研究：北太平洋西部海洋碳和氧吸收的物理和生物控制

• 批准号: 2049294
• 负责人: Manfredi Manizza
• 金额: $ 49.42万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2049294&HistoricalAwards=false
• 关键词: Collaborative; Research; Physical; biological; controls

Understanding the mechanisms that determine when and how the ocean takes up carbon from the atmosphere is important to our fundamental knowledge of ocean biogeochemistry and to our ability to model future climate. Air-sea fluxes of oxygen are also relevant to climatic variability, and surface oxygen can act as a tracer of biological carbon production and export as well as of important physical processes. The Kuroshio Extension region of the northwest Pacific Ocean is an area of strong carbon dioxide uptake and a site of wintertime watermass formation, with Subtropical Mode Water formed to the south of the Kuroshio Extension and lighter and denser Central Mode Water formed to the north. These mode waters then sink below the surface, moving carbon dioxide to the ocean interior. There are very few wintertime vertical profiles of any carbon system parameter in these mode water formation regions and no fully resolved winter or annual cycles of measurements. In this project, the investigators will deploy robotic profiling floats to make these needed measurements. They will combine the float data with numerical modeling to advance understanding of mode water formation and air-sea fluxes of carbon dioxide and oxygen in this important region. This proposal will fund an early career scientist and expand expertise in and capability for biogeochemical profiling float operations at the University of Hawai’i, providing a foundation for future work in autonomous biogeochemical platforms. This proposal will fund a graduate student in their Ph.D. work and multiple summer undergraduate researchers. Students will gain exposure to the complementary fields of marine chemistry, ocean physics, and climate models. The team will investigate carbon and oxygen budgets in the northwest Pacific from the following: new float observations of oxygen, nitrate, and estimated dissolved inorganic carbon; longer-term float temperature and salinity observations for water mass analysis; and model output. They will deploy biogeochemical Argo floats capable of measuring pH in the heart of the Subtropical and Central Mode Water formation regions in the Kuroshio Extension to provide vertical profiles of oxygen, nitrate, and, especially, estimates of dissolved inorganic carbon. They will use these observations to both calculate the drivers of air-sea carbon dioxide and oxygen fluxes and to validate model output for further analysis. Western boundary currents, such as the Kuroshio Extension, are areas of significant carbon dioxide uptake, but the relative importance of biology and physics to that uptake and its variability on large temporal and spatial scales is not well understood. The project has three main goals: (1) to determine what fraction of the CO2 and O2 uptake in the North Pacific is the result of mode water formation and subduction, (2) to determine how the physical and biological processes that drive air-sea fluxes vary spatially in the Kuroshio Extension region, and (3) to analyze the drivers of interannual and decadal variability of mode water formation and related gas fluxes in the Kuroshio Extension region and determine how that variability is linked to the larger climate system. The new observations will be evaluated in the larger context of multiple decades of observations from ships and almost two decades of physical observations from profiling floats. The team will use model output to diagnose physical drivers of air-sea fluxes and to link the observed mechanisms to longer-term variability and climate processes. The data collected will represent the first seasonally resolved profiles of oxygen, nitrate, and derived DIC in a western boundary current and will be of use to a broad community of researchers.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.

了解海洋何时以及如何从大气中吸收碳的机制对于我们了解海洋生物地球化学的基础知识以及我们模拟未来气候的海气通量的能力非常重要，这也与气候变化和地表氧气有关。可以作为生物碳生产和输出以及重要物理过程的示踪剂，西北太平洋的黑潮延伸区是二氧化碳吸收强烈的区域，也是冬季水团形成的场所，具有副热带模式水。形成的黑潮延伸区的南部和北部形成的较轻且较稠密的中心模式水随后沉入地表以下，将二氧化碳转移到海洋内部。这些区域中的任何碳系统参数都很少有冬季垂直剖面。在这个项目中，研究人员将部署机器人剖面浮标来进行这些所需的测量，他们将浮标数据与数值模型结合起来，以推进对模式水形成和空气的详细了解。 - 海洋中二氧化碳和氧气的通量该提案将资助一名早期职业科学家，并扩大夏威夷大学生物地球化学剖面浮式操作的专业知识和能力，为自主生物地球化学平台的未来工作奠定基础。他们的博士工作和多名夏季本科研究人员将接触海洋化学、海洋物理学和气候模型的互补领域，该团队将通过以下内容研究西北太平洋的碳和氧预算：新的浮标观测。氧气、硝酸盐和估计溶解的无机碳；用于水质量分析和模型输出的长期浮子温度和盐度观测；他们将部署能够测量黑潮延伸区的副热带和中部模式水形成区域的 pH 值的生物地球化学浮子。他们将利用这些观测结果来计算空气-海洋二氧化碳和氧气通量的驱动因素，并验证模型输出以进行进一步分析。黑潮延伸区等洋流是大量二氧化碳吸收的区域，但生物学和物理学对这种吸收的相对重要性及其在大时间和空间尺度上的变化尚不清楚。该项目有三个主要目标：（1。 ) 确定北太平洋吸收的二氧化碳和氧气的比例是水形成和俯冲模式的结果，(2) 确定驱动海气通量的物理和生物过程如何在黑潮延伸区空间变化，和(3) 分析黑潮延伸区水形成模式和相关气体通量的年际和年代际变化的驱动因素，并确定这种变化如何与更大的气候系统联系起来。新的观测结果将在更大的多重背景下进行评估。该团队将利用数十年的船舶观测和近二十年的剖面浮标物理观测来诊断海气通量的物理驱动因素，并将所收集的数据与长期变化和气候过程联系起来。代表第一个季节性解决的该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。