Two-Layer Flows in Rotating Channels
The exchange flow between a marginal sea or estuary and the open ocean is often approximated using two-layer stratification. Two-layer models are most convincing when the interfacial region separating the upper and lower fluids is relatively thin. The exchange flow in the Strait of Gibraltar exhibits this behavior, at least at certain locations and times (Figure I.9). The vertical density and velocity profiles taken near the Camerinal Sill show a relatively sharp transition between slab-like upper and lower water masses. Elsewhere, the Gibraltar interface can be thicker and can contribute significantly to the overall mass budget for the strait. The Bab al Mandab (BAM) exchange flow experiences variations throughout the water column that are quite continuous (Figures 1.10.7 and 5.0.1). Under such conditions, a two-layer model might still give guidance provided that motions over the water column are associated with the lowest internal mode of the stratified shear flow.
KeywordsFroude Number Potential Vorticity Hydraulic Jump Deep Basin Solution Curve
Unable to display preview. Download preview PDF.
- Bryden, H. L. and T. H. Kinder 1991. Steady two-layer exchange through the strait of Gibraltar. Deep-Sea Res. 38 (Suppl. 1), S445–S463.Google Scholar
- Bryden, H. L. and H. M. Stommel 1984. Limiting processes that determine basic features of the circulation in the Mediterranean Sea. Oceanologica Acta. 7, 289–296.Google Scholar
- Dalziel, S. B. 1988. Two-layer Hydraulics: Maximal Exchange Flows, PhD thesis. University of Cambridge, England.Google Scholar
- Houghton, D. D. and E. Isaacson 1970. Mountain winds. Stud. Numer. Anal. 2, 21–52.Google Scholar
- Jiang, Q. and R. B. Smith 2001a. Ideal shocks in two-layer flow. Part I: Under a rigid lid. Tellus 53A, 129–145.Google Scholar
- Phillips, O. M. 1966. On turbulent convection currents and the circulation of the Red Sea. Deep-Sea Res. 13, 1147–1160.Google Scholar
- Stommel, H. M. and H. G. Farmer 1952. Abrupt change in width in two-layer open chanel flow. J. Marine Res. 11, 205–214.Google Scholar
- Stommel, H. M. and H. G. Farmer 1953. Control of salinity in an estuary by a transition. J. Marine Res. 12, 13–20.Google Scholar
- Whitehead, J. A., M.-L. Timmermans, W. Gregory Lawson, S. N. Bulgakov, A. M. Zatarian, J. F. A. Medina and J. Salzig 2003. Laboratory studies of thermally and/or/salinity driven flows with partial mixing 1. Stommel transitions and multiple flow states. J. Geophys. Res. 108(C2), 3036, doi:10.1029/2001JC000902.CrossRefGoogle Scholar
- Yih, C. S. 1980. Stratified Flows. Academic Press, San Diego, 418pp.Google Scholar