CAREER: Multi-scale Interactions of Waves, Currents and Morphology with Application to Rip Currents

[0845957]该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。由于全球海平面上升、气候变化和人类活动加速，海岸侵蚀日益成为人们关注的问题。激波带的水动力对近岸沉积物的输运有重要影响，从而影响岸线侵蚀，对影响沿海海洋和洪泛平原水质的输运和混合有重要影响。了解近岸系统的复杂动态，对于开发可靠的预测工具，用于规划、管理和缓解，以建立一个可持续和有弹性的沿海环境，具有根本的相关性。本研究旨在通过研究三个关键近岸过程：波浪、水流和沉积物输运之间的多尺度相互作用来提高这一认识。离岸流是一种重要的近岸过程，也是一种危险的海滩灾害，占美国冲浪区救援的80%。对其产生机制的理论认识并不令人满意，特别是在缺乏沿岸变异性的海滩上。近年来的研究主要集中在形态动力学不稳定性上，强调水流与输沙之间的反馈作用，而没有充分考虑波浪与水流之间的动力学相互作用。本研究将探讨所有的多尺度相互作用。该研究将使用广泛的线性不稳定性分析，非线性多尺度动力学的数值模拟，并通过与观测结果的比较来验证模型。这里开发的方法将适用于其他环境系统的建模，包括河口和洪泛平原。研究和教育将通过开发沿海动力学和环境流体力学的研究生研究计划和课程来促进。这将重振北卡州立大学流体力学本科教育，强调其在自然环境中的作用。沿海工程研究的关键概念将通过合作倡议与教师直接互动，引入K-12科学课程。通过PI合作者的外展项目，包括国家气象局、陆军工程兵团野外研究设施、海洋基金和北卡罗来纳大学海岸研究所，预计将产生更广泛的影响。该项目由工程、地球科学和网络基础设施局共同资助。

0845957 YuThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Coastal erosion has increasingly become a concern due to rising global sea levels, changing climate and accelerating human activities. The hydrodynamics in the surf zone has significant influences on nearshore sediment transport, hence shoreline erosion, and on the transport and mixing that affect the water quality in coastal oceans and floodplains. Understanding the complex dynamics of the nearshore system is of fundamental relevance to the development of reliable predictive tools for planning, management and mitigation to build a sustainable and resilient coastal environment. This study aims to improve this understanding by investigating the multi-scale interactions among three key nearshore processes: waves, currents and sediment transport. Rip currents, an important nearshore process, are also a dangerous beach hazard, accounting for 80% of surf zone rescues in the US. Theoretical understanding of their generation mechanisms has not been satisfactory, in particular on beaches lacking alongshore variability. Recent studies have mostly focused on morphodynamic instabilities, stressing the feedback between currents and sediment transport but not fully considering the dynamical interaction between waves and currents. This research will investigate all multi-scale interactions. The research will use extensive linear instability analysis, numerical modeling of the nonlinear multi-scale dynamics, and model validation through comparisons with observations. The methodology developed here will be applicable in modeling other environmental systems including estuaries and floodplains. Research and education will be fostered by developing a graduate research program and curriculum in coastal dynamics and environmental fluid mechanics. This will rejuvenate undergraduate education in fluid mechanics at NC State to stress its role in natural environments. Key concepts of coastal engineering research will be brought into the K-12 science curriculum by direct interaction with teachers through a collaborative initiative. Further broad impacts are expected through the outreach programs of the PI's collaborators, including the National Weather Service, Army Corps of Engineers Field Research Facility, Sea Grant and UNC-Coastal Studies Institute.This project is being co-funded by the Engineering, Geosciences, and Cyber Infrastructure Directorates.