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Portland State University

2003

Columbia River

Articles 1 - 2 of 2

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Interfacial Mixing In A Highly Stratified Estuary: 2. A "Method Of Constrained Differences" Approach For The Determination Of The Momentum And Mass Balances And The Energy Of Mixing, David J. Kay, David A. Jay Mar 2003

Interfacial Mixing In A Highly Stratified Estuary: 2. A "Method Of Constrained Differences" Approach For The Determination Of The Momentum And Mass Balances And The Energy Of Mixing, David J. Kay, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

This article is Part 2 of a set of papers addressing mixing in a highly stratified estuary. In Part 2, turbulence and mean flow measurements are together used to understand the role of mixing in the overall dynamics of the system. Estimates of the partition of energy dissipation between bed-generated and internal mixing suggest that internal mixing accounts for about two thirds of the total turbulent kinetic energy (TKE) produced in the salt-wedge reach of the Columbia River estuary during the neap-tide, moderate river-flow observation period. This suggests that internal mixing plays a larger role in the energetics of such …


Particle Trapping In Stratified Estuaries - Definition Of A Parameter Space, David A. Jay, Philip M. Orton, Thomas A. Chisholm, Douglas J. Wilson, Annika M. Fain, John Mcginity Jan 2003

Particle Trapping In Stratified Estuaries - Definition Of A Parameter Space, David A. Jay, Philip M. Orton, Thomas A. Chisholm, Douglas J. Wilson, Annika M. Fain, John Mcginity

Civil and Environmental Engineering Faculty Publications and Presentations

Estuarine turbidity maxima (ETM) retain suspended particulate matter (SPM) through advection, settling, aggregation and non-linearities in bed processes. This contribution defines for the first time a parameter space descriptive of ETM water-column particle trapping processes through a scaling analysis of the local and integral SPM balances. In the absence of long-term deposition, there are five primary parameters for the large particles or aggregates that are typically trapped. Rouse number P, the ratio of settling velocity WS of the SPM relative to the shear velocity U*, describes the material trapped in the ETM in terms of the local vertical balance between …