Dynamics of and Transport by Buoyant Coastal Ocean Currents Driven by Spatially Distributed and Highly-Time Dependent Coastal Mountain Rivers

小型山区河流（SMR）系统已被证明是全球沉积物和颗粒有机碳通量的重要组成部分。它们也是沿海海洋营养物质和微量金属的重要间歇性来源。大规模的风暴事件是这些系统的主要淡水来源。随后向沿海海洋的排放在整个河流系统中连贯地发生，作为一个大的偶发脉冲，在此期间，风和浪通常在海洋上很强。河流羽流和浮力海岸流的动力学从这些间歇性的，但大脉冲的放电很少受到科学的关注。该数值模拟研究将量化SMR系统的组合浮力和风驱动流的动力学。一个理想化的SMR系统和SMR系统的俄勒冈州沿海范围的模型将被用来描述不同的排放和风力制度下的淡水和河流衍生材料的传输路径。智力优势：来自SMR系统（如俄勒冈州海岸山脉）河流的连贯但高度间歇性排放的浮力海岸流的动力学很少得到科学研究。然而，这些河流的瞬时总流量在冬季可能超过20，000 m3/s，超过了北部较大的哥伦比亚河的流量。在这些期间，内大陆架上的浮力强迫一定很重要。本研究将量化SMR浮力强迫的意义，表征浮力驱动和风驱动的俄勒冈州内大陆架环流之间的相互作用，并量化来自SMR河口的材料的命运和沿俄勒冈州海岸SMR河口之间的连通性。更广泛的影响：主要研究者将与林肯县学区教师合作，开发高中课程材料，重点是流域运输过程，河流对沿海海洋的影响，以及用于研究河流，河口和沿海流动的科学方法，包括建模和测量方法。课程将通过在线传播广泛分享。此外，还将向西北国家海洋可再生能源中心提供海流变化的模型预测和对俄勒冈州内大陆架主要强迫机制的描述，以促进其在俄勒冈州海岸外的波浪能研究、开发、设备测试和影响研究。一名博士研究生将在这笔赠款下接受培训。她/他的研究重点将是了解SMR系统对俄勒冈州沿海浮力环流的作用。

Small mountainous river (SMR) systems have been shown to contribute a significant fraction of the global sediment and particulate organic carbon fluxes to the ocean. They are also important intermittent sources of nutrients and trace metals to the coastal ocean. Large-scale storm events are the dominant source of freshwater for these systems. Subsequent discharge to the coastal ocean occurs coherently across the river system as a large episodic pulse during which winds and waves are typically strong over the ocean. The dynamics of river plumes and buoyant coastal flows from these intermittent, but large pulses of discharge have received little scientific attention. This numerical modeling study will quantify the dynamics of the combined buoyancy and wind driven flows of an SMR system. Models of an idealized SMR system and the SMR system of the Oregon coastal range will be used to characterize the transport pathways of freshwater and river derived materials under different discharge and wind regimes. Intellectual Merit: The dynamics of buoyant coastal flows from the coherent but highly intermittent discharge of rivers of an SMR system, such as that of Oregon coastal range, have received very little scientific study. Yet the instantaneous combined discharge from these rivers can be greater than 20,000 m3/s during the winter, exceeding the discharge of the larger Columbia River to the north. Buoyancy forcing on the inner shelf must be important during these periods. This study will quantify the significance of SMR buoyancy forcing, characterize the interactions between the buoyancy driven and wind driven circulation of the Oregon inner shelf and quantify the fate of materials derived from SMR estuaries and the connectivity between SMR estuaries along the Oregon coast. Broader Impact: The principal investigator will collaborate with Lincoln County School District teachers to develop high school curriculum material focused on watershed transport processes, the impact of rivers on the coastal ocean, and scientific methods used to study river, estuary, and coastal flow including modeling and measurement methods. The curriculum will be shared broadly through online dissemination. In addition, model predictions of current variability and a description of the dominant forcing regimes of the Oregon inner shelf will be provided to the Northwest National Marine Renewable Energy Center in order to facilitate their wave energy research, development, device testing and impact studies off the Oregon coast. A PhD graduate student will be trained under this grant. The focus of her/his research will be on understanding the role of SMR systems on buoyant coastal circulation off of Oregon.