Collaborative Research:  Using Salinity Variance to Link Estuarine Mixing and Exchange Flow

GSTDTAP

项目编号	1736539
	Collaborative Research: Using Salinity Variance to Link Estuarine Mixing and Exchange Flow
	Wayne Geyer
主持机构	Woods Hole Oceanographic Institution
项目开始年	2017
	2017-09-15
项目结束日期	2020-08-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	570585(USD)
国家	美国
语种	英语
英文摘要	This project aims at advancing our understanding of the physical processes operating in estuaries using the variance of salinity. Salinity is one of the most important quantities defining an estuary and its variance in the horizontal variance provides the driving force for the gravitational circulation. Vertical variance of salinity quantifies stratification, which strongly affects and is affected by the shear, turbulence and mixing. The salinity variance balance equation has been effectively exploited in the turbulence community to quantify mixing, but it has received surprisingly little attention in context with estuarine dynamics, despite its fundamental importance. This project will analyze the salinity variance balance in a variety of estuaries using realistic and idealized numerical models. The insights gained from the analysis will provide a more systematic understanding of estuarine dynamics, using a common framework to compare rates and mechanisms across the estuarine parameter space. The analysis approach will also have application to exchange flows and mixing in the coastal and global ocean. This project will also support a graduate student at each of the two institutions and contribute to their training. The PIs also plan to teach a 5-week summer class for graduate students entitled "Estuarine Dynamics: Observations and Realistic Models." The class will involve 12-15 graduate students interested in estuarine processes. The students will gain hands-on field experience, and they will also apply and analyze realistic models, thereby developing a sense of the challenge and synergy that comes from bringing together observations and models. This project will develop the mathematical framework of the salinity variance to quantify the integral relationships between exchange flow and mixing, and then apply those relationships to diverse estuarine settings. In addition to these integral relationships, the analysis will examine the local exchange between horizontal and vertical variance via straining, and determine the consequences for temporal and spatial variations of stratification and mixing. Here "mixing" is defined as the irreversible loss of salinity variance by turbulent and molecular processes. The analysis will address these fundamental questions: Is exchange flow controlled by mixing, or vice versa? How do mixing and exchange flow respond to variations in tidal amplitude in different estuarine regimes? How does estuarine geometry affect mixing and exchange flow? How does straining by estuarine and tidal shear vary in different regimes, and how does straining modulate the exchange between horizontal and vertical variance and thereby enhance or suppress mixing? The answers to these questions will lead to a predictive framework for the variability of estuarine mixing and exchange flow in relation to the estuarine geometry and the dominant forcing parameters; river discharge and tides.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/72014
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Wayne Geyer.Collaborative Research: Using Salinity Variance to Link Estuarine Mixing and Exchange Flow.2017.