Circulations and Density Distributions in a Deep, Strongly Stratified, Two-Layer Estuary.
Abstract
The paper discusses a theoretical model of statistically steady flow in a strongly stratified estuary. A halocline is assumed to be present and the lower layer is taken to be deep and non-turbulent. The outflowing upper fluid mixes with the salty lower fluid and the flux of the brackish water increases with distance from the head of the estuary. The mixing is assumed to be similar to that in laboratory models of mixing across density interfaces. The mathematical problem reduces to two ordinary differential equations for the flux in the upper layer and the thickness of the layer. Attention is confined to the solution for subcritical flow in which the interface falls with distance from the head reaching a maximum depth at a certain section of the estuary. Beyond this the interface rises. At the mouth, where, by definition, the width of the estuary increases rapidly, it is shown that there must be a transition from subcritical to supercritical flow. This condition, applied to the solution for uniform width, determines a remaining unknown, related to the depth of the halocline at the head of the estuary and the complete solution is obtained as a function of fresh-water influx per unit width, the rms turbulent velocity, the estuary length and the buoyancy of sea water.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1975
- Accession Number
- ADA006737
Entities
People
- Robert R. Long
Organizations
- Johns Hopkins University