Stratified Fronts in Well-Mixed Estuaries
Abstract
The occurrence of tidal intrusion fronts in a well-mixed estuary is demonstrated through both model simulation and field observation. Strong vertical mixing in well-mixed estuaries typically does not allow for development of stratification, which is a defining feature of tidal intrusion fronts. New methodology to compute a mutual realization surface of critical width and depth from model output is described that evaluates how the geometry of a basin releases tidal inflow from the hydraulic control of an inlet and the resulting front character. Force balance relationships of these features are evaluated in three dimensions for the first time. From this, Froude angle techniques are adapted to assess and predict how the geometry controls the behavior of the front after it is formed. Intrusion fronts observed in the field do not precisely conform to the conceptual model, but a modest field validation of Froude angle usage informs an axis rotation that results in agreement with established hydraulic theory. Frontogenetic mechanisms are proposed from the observations to describe the importance of morphological complexity and water mass segregation to the occurrence of bathymetrically induced confluent subduction in a well-mixed estuary.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2013
- Accession Number
- ADA589446
Entities
People
- Micah A. Weltmer
Organizations
- Naval Postgraduate School