Coastal Ocean Carbon Cycling during Wintertime Conditions

与世界上许多沿海地区一样，太平洋西北边缘的特点是控制大气、陆地和海洋之间碳通量的条件存在强烈的季节性差异。在冬季，太平洋西北部沿海小河流迅速而强烈的洪水泛滥以及与之相关的淡水、营养物质和有机物的输入是司空见惯的。在全球和区域范围内，这些易发洪水的小河流冬季陆海转移对太平洋西北部等上升流地区的影响被低估。为了对海洋边缘的碳循环有一个完整和可预测的了解，需要全面研究密集的陆地-海洋转移时期的生物地球化学。该项目将结合船上、滑翔机、系泊和远程测量，评估冬季陆地输入活跃和生物循环期间沿上升流主导边缘的有机物质循环的动力学。通过海洋观测倡议(OOI)*和俄勒冈沿海现有科学基础设施在海洋观测技术方面的新发展将有助于实现这一目标。这项工作将为本科生和研究生提供研究机会，并将通过海洋科学教育卓越太平洋伙伴关系中心、当地沿海社区大学以及俄勒冈州立大学哈特菲尔德中心、Umpqua发现中心和俄勒冈海岸水族馆等解释中心进行推广，努力向学生和公众宣传这项研究。从全球来看，大多数关于东部边界地区碳循环的研究都集中在夏季的上升流阶段，导致对非上升流期的理解要差得多。与许多沿海上升流系统一样，太平洋西北边缘的冬季条件以南下有利的风和潮湿的风暴为特征，导致该地区许多中小型河流发生季节性洪水。这些沿海河流排放量的增加转化为大量陆源生物地球化学相关成分的输入，包括淡水、溶解的无机营养物质以及溶解的和颗粒的有机物，这些共同构成或超过哥伦比亚河。为了了解洪水引发的陆地输入对太平洋西北边缘海岸带生物地球化学的影响，研究人员将在秋冬季条件下对俄勒冈州中部沿海纽波特水道线沿线水柱中的生物地球化学过程进行详细调查。该项目包括一项密集的实地工作，利用船基和自主平台获得全面的冬季覆盖。在项目成果中，这一努力将导致对沿海边缘碳循环的生物地球化学驱动因素进行修订。*海洋观测站倡议(OOI)是由美国国家科学基金会资助的、由科学驱动的传感器系统组成的网络化基础设施，用于测量海洋和海底的物理、化学、地质和生物变量。欲了解有关OOI的更多信息，请访问网站：www.Ocean Watch atories.org。

As is true for many coastal regions worldwide, the Pacific Northwest margin is characterized by intense seasonal contrasts in conditions controlling carbon flux between the atmosphere, land, and ocean. During the wintertime, rapid and intense flooding of small coastal rivers and the associated inputs of freshwater, nutrients, and organic matter are commonplace in the Pacific Northwest. Impacts of these wintertime terrestrial-ocean transfers by small, flood-prone rivers on the upwelling regions, such as the Pacific Northwest, have been underestimated at both global and regional scales. In order to gain a complete and predictive understanding of carbon cycling in ocean margins, the biogeochemistry of periods of intense terrestrial-ocean transfers needs to be comprehensively studied. This project will evaluate the dynamics of organic matter cycling along an upwelling-dominated margin during the wintertime period of active terrestrial inputs and biological cycling using a combination of shipboard, glider, moored and remote measurements. New developments in ocean observational technologies through the Ocean Observatories Initiative (OOI)* and existing scientific infrastructure along the Oregon coast will be instrumental in achieving this goal. This work will provide research opportunities for undergraduate and graduate students, and outreach will be conducted through the Centers for Ocean Science Education Excellence Pacific Partnership, local coastal community colleges, and interpretative centers such as Oregon State University Hatfield Center, the Umpqua Discovery Center, and Oregon Coast Aquarium in an effort to educate students and the public about the research.Globally, most studies of carbon cycling in eastern boundary regimes have focused on the upwelling phase during the summer months, resulting in a much poorer understanding of non-upwelling periods. As is many coastal upwelling systems, wintertime conditions along the Pacific Northwest margin are characterized by southerly, downwelling-favorable winds and moisture-laden storms that result in seasonal flooding by the numerous small to medium-sized rivers in the region. Elevated discharges by these coastal rivers translate into large inputs of land-derived biogeochemical relevant constituents, including freshwater, dissolved inorganic nutrients, and dissolved and particulate organic matter, which collectively rival or exceed those of the Columbia River. To understand the impact of flood-derived terrestrial inputs on the biogeochemistry of the coastal zone along the Pacific Northwest margin, researchers will conduct a detailed investigation of biogeochemical processes in the water column along the Newport Hydrographic Line off the central Oregon coast during fall/winter conditions. The project includes an intensive field effort that takes advantage of ship-based and autonomous platforms to gain comprehensive wintertime coverage. Among the project outcomes, this effort will lead to a revised paradigm of the biogeochemical drivers of carbon cycling in coastal margins.*The Ocean Observatories Initiative (OOI) is an NSF-funded, networked infrastructure of science-driven sensor systems to measure the physical, chemical, geological and biological variables in the ocean and seafloor. For more information about OOI, please visit the website: www.oceanobservatories.org