On the application of hydraulic theory to the deep-water flow through the Irbe Strait

A flow-dependent critical-point method for investigating topographically co ntrolled flow in natural channels is applied to the bottom current through the Irbe Strait connecting the Baltic proper and the Gulf of Riga. This app roach is based on the functional formalism due to Gill [Gill, A.E., 1977. T he hydraulics of rotating-channel flow. J. Fluid Mech., 80, 641-671.], and here is used for the stratified flow structure observed during the IRBEX-95 field campaign. A critical section of the realizable flow regime was found to be located slightly downstream of the most pronounced horizontal constr iction of the channel. The predicted baroclinic volume flux 7200 m(3) s(-1) overestimates the observed mean bottom-water transport by around 30%, a di screpancy which most likely can be explained by the lack of sea level condi tions and friction in the model. (C) 2000 Elsevier Science B.V, All rights reserved.