Collaborative Research: The Role of Coastal Fronts in Mixing and Ventilating Coastal Waters

海岸锋是上层海洋的区域，具有将不同水团分开的尖锐边界。锋面与增强湍流和垂直速度的条件有关。强烈的分层，流动收敛，并加强锋附近的垂直通量之间的相互作用有重要的和直接的影响，在世界海洋的气体和能量交换。将使用最先进的方法进行详细观测，包括使用装有仪器的自主水下航行器和漂流平台，以解决导致沿海锋附近混合和垂直交换增强的细尺度动态。收集的数据和随后的分析将改善对汇率的估计，这些汇率决定了系统对酸化和缺氧、初级生产和物质运输的敏感性。这项研究将提高我们预测和管理沿海海洋酸化和缺氧的能力，并使对上层海洋交换过程的新的调查成为可能。该项目还将促进一名青年科学家的职业发展。外联工作包括参加一年一度的华盛顿大学探索日活动，该活动吸引了来自地区K-12学校的10，000多名学生参观校园并了解当前的研究。在多个层次的学生参与将通过追求本科研究机会，通过NSF REU计划，以及促进研究生和本科生在土木和环境工程系在华盛顿和加州大学圣巴巴拉的参与促进。表面波破碎，气泡夹带，并在附近的沿海前线下降流收敛之间的相互作用是研究的重点，主要目标是调查在这些位置的湍流交换的具体性质和瞬态。拟议的工作建立在使用SWIFT漂移器以及REMUS 600自主水下航行器测量上层海洋湍流耗散率的最新结果的基础上。湍流能量和雷诺应力的详细测量将提供一个变革性的观点交换过程中的情节和瞬态锋的功能。这将通过控制量分析和地形形状阻力的估计与驱动锋生的动力学联系起来。通过收集全面的现场测量建议，在通风和混合沿海和河口沃茨的表面锋的作用（S）将定量characterized.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Coastal fronts are regions of the upper ocean with sharp boundaries that separate distinct water masses. Fronts are associated with conditions of enhanced turbulence and vertical velocities. Interactions between strong stratification, flow convergence, and enhanced vertical fluxes near fronts have important and immediate implications for gas and energy exchange within the world’s oceans. Detailed observations using state-of-the-art methods that include an instrumented autonomous underwater vehicle (AUV) and drifting platforms would be used to resolve fine scale dynamics that lead to the enhancement of mixing and vertical exchange in the vicinity of a coastal front. The data collected and subsequent analysis would improve estimates of exchange rates that determine a system’s susceptibility to acidification and hypoxia, primary production, and transport of material. This study will improve our ability to predict and manage coastal ocean acidification and hypoxia, as well as enable new lines of inquiry into upper ocean exchange processes. The project will also contribute to the development of the career of a young scientist. Outreach efforts include participation in the annual University of Washington Discovery Days event, which draws over 10,000 students from regional K-12 schools to visit the campus and learn about current research. Student participation at multiple levels would be fostered by pursuing undergraduate research opportunities through the NSF REU program as well as promote involvement of graduate and undergraduate students within the Department of Civil and Environmental Engineering at the University of Washington and UC Santa Barbara. The interaction between surface wave breaking, bubble-entrainment, and downwelling convergence in the vicinity of coastal fronts are the focus of the study, with the primary goal being to investigate the specific nature and transiency of turbulent exchange at these locations. The proposed work builds on recent results using SWIFT drifters as well as a REMUS 600 autonomous underwater vehicle to measure upper ocean turbulent dissipation rates. Detailed measurements of turbulent energetics and Reynolds stresses will provide a transformative view of exchange processes at episodic and transient frontal features. This would be linked to dynamics driving frontogenesis through control volume analyses and estimates of topographic form drag. Through the collection of comprehensive in-situ measurements proposed here, the role(s) of surface fronts in ventilating and mixing coastal and estuarine waters would be quantitatively characterized.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.