权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Collaborative Research: Lagrangian transport and patchiness of buoyant material in estuarine systems

合作研究：河口系统中浮力物质的拉格朗日输送和斑块性

基本信息

批准号：
2148370
负责人：
Tobias Kukulka
金额：
$ 57.46万
依托单位：
University of Delaware
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-03-01 至 2025-02-28
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2148370&HistoricalAwards=false
关键词：
Collaborative Research Lagrangian transport patchiness

项目摘要

Understanding processes that transport material in estuarine systems is central to fundamental studies of estuarine physics as well as to management practices in these socioeconomically important and highly anthropogenically impacted systems. Buoyant material, such as floating debris, marine organisms, oil and microplastics may be aggregated and trapped within estuaries or dispersed and discharged to the coastal ocean by these transport processes. Strong convergent surface flows across the estuary organize buoyant material into laterally narrow near-surface patches that may extend up to a few kilometers along the estuary. Local currents that move these patches may substantially differ from tidally and laterally averaged currents, which are often used to estimate estuarine transport characteristics. A major objective of this project is to contrast the transport of material in a frame work that follows the flow, known as the Lagrangian framework, with one based on a fixed point reference frame, or the Eulerian framework. Often the Lagrangian trajectories of material differ from those inferred from the Eulerian mean flows. The classic example stems from surface waves where the average velocity at a point (Eulerian) will be zero but a particle oscillating with the wave included flow will have an average velocity in the direction of wave propagation, due to the Stokes drift or Stokes velocity. This project will investigate the importance of Stokes transport in estuaries. The project research hypotheses are: (1) Stokes transport associated with amplitude and phase structure of tidal flows contribute significantly to the transport of buoyant material in both the along-channel and cross- channel directions. (2) Buoyant material organizes in surface patches due to the lateral estuarine circulations. (3) Patches of buoyant material are fundamentally transported by spatiotemporally localized currents that vary substantially across the estuary. (4) The observed spatiotemporal distributions of marine debris in Delaware Bay are a characteristic signature of Lagrangian estuarine transport. The project will use both modeling and observations to address transport of buoyant material in estuaries. This research will help solve practical real world problems related to marine pollution, gas exchange and fisheries. The PIs have close working relationships with resource managers and policy makers with whom they will communicate relevant new understanding. The project will train graduate and undergraduate students, and both PIs and students will participate in public outreach events. This project will examine transport of buoyant material in estuaries, specifically the Delaware Estuary, including its aggregation within estuaries, and the effects of resulting patchiness of buoyant material on its transport through the estuary. The hypotheses will be addressed through an integrated research program that employs original concept models as well as observations and simulations. Research objectives include: (1) Assess and advance idealized linear and weakly-nonlinear models of the three-dimensional estuarine circulations to determine key factors that control secondary circulations, such as bathymetry, tides, Coriolis force, and baroclinicity. (2) Develop and evaluate a Lagrangian framework for the estuarine circulation based on the integration of the idealized models with existing field observations and an asymptotic Stokes drift analysis to contrast fundamental differences between the Eulerian and Lagrangian approaches. (3) Conduct and integrate hydrodynamic simulations and field observations of the Delaware Estuary to understand tidal neap-spring and high-low river discharge variability. (4) Apply the Lagrangian framework to simulation and observation results, as well as recent marine debris observations, to reveal principal Lagrangian transport characteristics and improved estuarine transport estimates. By exploring and developing a Lagrangian framework this project would fundamentally advance our understanding of the physics of estuarine transport processes. This work will transform the current paradigm of estuarine material transport to include new lateral transport processes, thereby advancing the current conceptual understanding of buoyant tracer dynamics in an estuary, and will contribute to solving practical real world problems.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.

了解过程中，运输材料的河口系统是中央河口物理学的基础研究，以及在这些社会经济重要的和高度adhergenically影响系统的管理实践。漂浮物、海洋生物、石油和微塑料等浮力物质可能会聚集并滞留在河口，或通过这些运输过程分散并排放到沿海海洋。强大的收敛表面流在河口组织成横向狭窄的近地表补丁，可能会延伸到几公里沿着河口浮力材料。移动这些补丁的本地电流可能会有很大的不同，潮汐和横向平均电流，这是经常用来估计河口运输特性。该项目的一个主要目标是将遵循流动的框架（称为拉格朗日框架）中的材料运输与基于固定点参考框架或欧拉框架的材料运输进行对比。物质的拉格朗日轨线常常不同于从欧拉平均流推断出的轨线。经典的例子源于表面波，其中在一个点（欧拉）处的平均速度将为零，但是由于斯托克斯漂移或斯托克斯速度，与包含波的流一起振荡的粒子将在波传播方向上具有平均速度。这个项目将调查河口斯托克斯输运的重要性。本课题的研究假设是：（1）与潮流振幅和相位结构相关的Stokes输运对沿槽和跨槽方向的浮力物质输运都有重要贡献。(2)浮力物质组织在表面斑块由于横向河口环流。(3)漂浮物质的补丁从根本上运输的时空本地化的电流，变化很大，整个河口。(4)观测到的特拉华州湾海洋废弃物的时空分布是拉格朗日河口输送的特征信号。该项目将使用建模和观测来解决河口漂浮物质的运输问题。这项研究将有助于解决与海洋污染、气体交换和渔业有关的实际真实的世界问题。项目执行人与资源管理人员和决策者有密切的工作关系，他们将与他们交流有关的新认识。该项目将培训研究生和本科生，PI和学生都将参加公共宣传活动。该项目将研究河口，特别是特拉华州河口的浮力材料的运输，包括河口内的聚集，以及由此产生的浮力材料的斑块对其通过河口运输的影响。这些假设将通过采用原始概念模型以及观察和模拟的综合研究计划来解决。研究目标包括：（1）评估和改进三维河口环流的理想化线性和弱非线性模式，以确定控制次级环流的关键因素，如水深、潮汐、科里奥利力和斜压性。(2)开发和评估拉格朗日框架的河口环流的基础上整合的理想化模型与现有的现场观测和渐近斯托克斯漂移分析，以对比欧拉和拉格朗日方法之间的根本差异。(3)进行并整合特拉华州河口的水动力模拟和现场观测，以了解潮汐小潮-春季和高低河流流量的变化。(4)将拉格朗日框架应用于模拟和观测结果，以及最近的海洋废弃物观测，以揭示主要的拉格朗日输运特征和改进的河口输运估计。通过探索和开发拉格朗日框架，该项目将从根本上推进我们对河口运输过程物理学的理解。这项工作将改变目前的范例河口物质运输，包括新的横向运输过程，从而推进目前的概念性理解浮力示踪动力学在河口，并将有助于解决实际的真实的世界problems.This奖反映了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。