Oxygen and Carbon-based Production and Respiration Rates Across the Pacific Ocean from Profiling Floats

来自剖面浮标的跨太平洋氧气和碳基生产和呼吸速率

• 批准号: 2220332
• 负责人: Fernanda Henderikx-Freitas
• 金额: $ 91.22万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2220332&HistoricalAwards=false
• 关键词: Oxygen; Carbon; based; Production; Respiration

Ocean chemistry and biology play an important role in the global carbon cycle. This project will characterize key components of biological carbon cycling in the Pacific Ocean. The team will use profiling floats (autonomous vehicles equipped with several sensors) to measure oxygen and particulate carbon concentrations and estimate the amount of carbon and oxygen produced, consumed, and lost by algae, bacteria, and other organisms in the top 200 meters of the ocean on a day-to-day basis across all seasons. They will also make direct measurements of these daily quantities and other properties from a research ship. The ship-based measurements will be used both to calibrate the float measurements and to determine how the ratio of oxygen produced to carbon dioxide absorbed during photosynthesis, as well as the ratio of oxygen utilized per organic carbon molecule consumed during respiration, vary over space. These quantities are poorly understood and are rarely measured but are critical to determine marine ecosystem health. In addition to allowing measurements over a full seasonal cycle, the float data will support validation of satellite-based methods for estimating carbon production over broad areas of the ocean. Collectively these efforts address the critical need for better understanding how ocean productivity changes over time and space and how much carbon is sequestered to the deep ocean due to biological processes. The project will include active participation of graduate and undergraduate students at sea. The researchers will also participate as mentors in the Indigenous Partnership for Ocean Monitoring led by the Consortium for Increasing Research and Collaborative Learning Experiences, CIRCLE, program at the University of Hawai’i. This program engages local high school students to conduct research to learn about the connection between their health and the health of the ocean. Students will be trained to analyze float and satellite data. In order to determine the metabolic state of global oceans over time and space, we must be able to accurately characterize both primary production (PP) and community respiration (CR) rates. Spatial and temporal variations in PP are poorly known because the effort required for the traditional carbon and oxygen-based bottle incubation methods limits their application. Satellite-based PP estimates on which we rely for regional and global patterns are poorly validated and can be inaccurate. Building upon preliminary work demonstrating that diel cycles of dissolved oxygen and optically-derived particulate carbon obtained via autonomous profiling floats can yield reliable estimates of gross production (GP) and community respiration (CR) rates in the North Pacific Ocean, the team plans to resolve the seasonal cycle of GP and CR across the Pacific basin using long-term float deployments programmed to obtain diel-resolving measurements of oxygen and particulate carbon throughout the euphotic zone. Previous ship-based work in the subtropical and subpolar North Pacific regions found ecosystems marked by consistent production to respiration ratios, which was unexpected given the approximately 10-fold increases in biomass, particulate carbon, and chlorophyll, and 50-fold increase in nitrate across the region. It is unclear how these ratios may vary over time, whether patterns extend to the Equatorial and South Pacific oceans, and what role dissolved organic matter production and respiration, particle export, and phytoplankton composition may have in driving and/or biasing measured rates. Together, float-based rates and ship-based experiments will shed light into those unknowns, allowing an unprecedented view into basin-scale ecosystem functioning. The team expects to obtain approximately 70 oxygen-and carbon-based daily rates per float per year over the seasonal cycle, potentially revolutionizing our understanding of how production and respiration rates vary over time and space. This effort will showcase a powerful means to evaluate satellite-based PP estimates across vast areas of the ocean, which has been critically needed.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.

海洋化学和生物学在全球碳循环中起着重要作用。该项目将表征太平洋生物碳循环的关键组成部分。该团队将使用分析浮子（与几种传感器相当的自动驾驶汽车）来测量氧气和颗粒碳浓度，并估算在整个季节的每日200米中，藻类，细菌和其他生物体产生，消耗和消耗的碳和氧气量。他们还将直接从研究船上对这些每日数量和其他特性进行直接测量。基于船舶的测量结果将既用于校准浮点测量值，又确定在光合作用过程中吸收的氧氧与二氧化碳的比率，以及在呼吸过程中消耗的每个有机碳分子所用的氧之比，在空间上有所不同。这些数量的理解很差，很少被测量，但对于确定海洋生态系统健康至关重要。除了允许在整个季节性周期内进行测量外，浮点数据还将支持基于卫星的方法验证以估计海洋广阔区域的碳生产的方法。这些努力共同解决了更好地理解海洋生产力如何随时间和空间变化以及由于生物过程隔离到深海的关键需求。该项目将包括在海上积极参与研究生和本科生。研究人员还将作为导师参加由财团领导的土著海洋监测伙伴关系，以增加研究和协作学习经验，圈子，夏威夷大学计划。该计划使当地高中生进行研究，以了解其健康与海洋健康之间的联系。学生将接受培训以分析浮点和卫星数据。为了确定全球海洋的代谢状态，我们必须能够准确地表征初级生产（PP）和社区呼吸（CR）率。 PP的空间和临时变化是众所周知的，因为传统的碳和基于氧气的瓶孵化方法所需的努力限制了其应用。我们依赖于区域和全球模式的基于卫星的PP估算值得不正确，并且可能不准确。在初步工作的基础上表明，通过自主分析浮子获得的溶解氧和光学衍生的特定碳的DIEL周期可以产生北太平洋总生产（GP）和社区呼吸率（GP）和社区呼吸率（CR）的可靠估计，该团队计划使用GP的季节性和cr跨太平洋基础的季节性衡量 - 以解决PACIFIFIC BAYS的季节性，并进行了Pacific basin sopliment diel diel diel distry diel disterime diel distry diel。在整个舒适区域中的特定碳。先前在亚热带和亚波面北太平洋地区的基于船舶的工作发现生态系统以一致的产生与呼吸率为特征，这是出乎意料的，鉴于生物量增加了约10倍，特定碳和叶绿素的增长约10倍，并且该地区的硝酸盐增加了50倍。目前尚不清楚这些比率如何随着时间的流逝而变化，模式是否扩展到赤道和南太平洋，以及在驾驶和/或偏见测得的速率中可能具有溶解有机物的产生和呼吸，颗粒出口以及植物浮游生物组成的何种作用。总之，基于浮点的费率和基于船舶的实验将使那些未知数的灯光散发出来，从而使盆地规模生态系统运作的前所未有。该小组预计，在整个季节性周期中，每年每年的氧气和基于碳的每日速率将获得大约70个氧气和碳的每日速率，这可能会彻底改变我们对生产和呼吸率如何随时间和空间变化的理解。这项工作将展示一种有力的手段，以评估跨海洋地区的基于卫星的PP估计值，这是至关重要的。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，被视为通过评估来获得支持。