Redox dynamics resulting from chemical and physical fluxes in surficial permeable sediments

在相关的空间和时间尺度上对分析物进行现场测量的能力以及对孔隙水输送特性的需要限制了对渗透性沉积物中化学通量的测量。来自夏威夷大学的两位科学家将结合原位电化学、建模、传统地球化学和涡流相关氧通量测量系统来解决近岸渗透性沉积物的生物地球化学通量。这项研究将在基洛纳鲁电缆近岸珊瑚礁天文台进行，该天文台将提供(1)数据采集和数据传播系统；(2)现场仪器的无障碍电源和高带宽通信；(3)广泛的海洋物理测量；瓦胡岛？美国南岸有广泛和可预测的各种表面波条件和陆地输入，影响其渗透性沉积物的氧化还原敏感生物地球化学。本研究结果将用于：(1)提高我们对这些活性碳循环沉积物与上覆水柱之间相互作用的理解；(2)详细研究了关键氧化还原反应化学物质的时空变异；(3)量化底栖生物光合作用、沙纹位置、海流和波浪以及偶发性有机负荷事件对氧化还原振荡的相对贡献；4)将精细尺度化学测量与孔隙水速度模拟相结合，计算生物地球化学通量。就更广泛的影响而言，该项目将大大增进我们对可渗透沉积物/海水界面上溶质通量的认识，并提高我们对这类沉积物中的生物地球化学过程的理解。此外，这项研究将为海洋科学界提供新的原位传感器技术。外展活动包括通过毕晓普博物馆对公众进行教育，并为网站和威基基酒店展示的教育视频提供他们的研究信息。一名博士后、一名研究生和一名本科生将作为该项目的一部分得到支持和培训。

The ability to make in situ measurements of analytes on relevant spatial and temporal scales and the need for robust porewater transport characterizations have limited measurements of chemical fluxes within permeable sediments. Two scientists from the University of Hawaii will combine in situ electrochemistry, modeling, traditional geochemistry, and an eddy correlation oxygen flux measuring system to address the biogeochemical fluxes from nearshore permeable sediments. The research will be carried out at the Kilo Nalu Cabled Nearshore Reef Observatory which will provide (1) data acquisition and data dissemination systems; (2) accessible power and high bandwidth communications for in situ instruments; (3) a wide range of physical oceanographic measurements; and (4) Oahu?s south shore has a wide and predictable variety of surface wave conditions and land-based inputs that impact the redox-sensitive biogeochemistry of its permeable sediments. Results from this study will be used to (1) improve our understanding of the interaction between these active, carbon recycling sediments and the overlying water column; (2) examine in detail the temporal and spatial variability of key redox-reactive chemical species; (3) quantify the relative contributions of benthic photosynthesis, sand ripple position, currents and waves, and episodic organic loading events to redox oscillations; and 4) integrate fine-scale chemical measurements with porewater velocity modeling to calculate biogeochemical fluxes.As regards broader impacts, this project will significantly further our knowledge of the solute fluxes across the permeable sediment/seawater interface, as well as improve our understanding of biogeochemical processes within these types of sediments. In addition, this research would make novel in situ sensor technology available to the ocean sciences community. Outreach activities include education of the public via the Bishop Museum and providing information on their research for websites and educational videos displayed in Waikiki hotels. One postdoc, one graduate student and one undergraduate student would be supported and trained as part of this project.