Archipelago strait exchange processes - an overview
2004 (English)In: Deep-sea research. Part II, Topical studies in oceanography, ISSN 0967-0645, Vol. 51, no 4-5, 371-392 p.Article in journal (Refereed) Published
Archipelagos consist of a set of islands forming a collection of basins interconnected by straits, and are typically characterized by widely varying spatial and temporal scales regarding geometry and forcing conditions. Focusing on the strait exchange parameterization, we describe an archipelago water exchange model in which the archipelago is subdivided into a network of discrete basins and interconnecting straits and where the time integration assumes a series of quasi-steady states. We propose an algorithm that should be sufficiently flexible to provide reasonable strait exchange estimates under the variety of forcing conditions encountered in the Stockholm archipelago. We start from the functional formulation of two-layer hydraulic theory, which allows numerical schemes to be designed that, given the forcing conditions at the ends of a given strait, distinguish between maximal and sub-maximal flow cases and solve the flow accordingly. We relax the assumption of two homogeneous layers when necessary, using an approximate method based on a self-similarity assumption and with the sea-level difference over the strait as an explicit part of the problem. This method allows exchange flows with two groups of layers to be solved for the same set of geometries that the pure two-layer theory can handle, including sill-contraction combinations and non-rectangular cross-sections. We further show how aspiration of dense water from below the sill crest can be quantified with hydraulic theory, and be included in the method for stratified strait exchange. Rotational control in wide straits and in parallel straits connecting the same two basins is treated with a simple but robust scheme. We evaluate the calculations with data from the Oxdjupet strait in the Stockholm archipelago. Simulations with a three-dimensional, non-hydrostatic numerical model are performed to compensate for sparsity in data.
Place, publisher, year, edition, pages
2004. Vol. 51, no 4-5, 371-392 p.
maximal 2-layer exchange, bab al mandab, hydraulic control, stratified fluid, water exchange, cross-sections, flow-through, contraction, channel, ocean
Oceanography, Hydrology, Water Resources
IdentifiersURN: urn:nbn:se:kth:diva-43938DOI: 10.1016/j.dsr2.2003.09.003ISI: 000222987200005ScopusID: 2-s2.0-3042693236OAI: oai:DiVA.org:kth-43938DiVA: diva2:451252
QC 201110252011-10-252011-10-192011-11-01Bibliographically approved