Abstract
[Truncated] The study of hydrodynamics in lakes involves a broad spectrum of time and space scales that define how mass, momentum and energy are transported throughout lake ecosystems. As a result, hydrodynamics are inherently linked to the two major energy fluxes paths in lake ecosystems: the flux of mechanical energy through the water motion and the flux of chemical energy through the aquatic food web. The ability to simulate the interplay between processes occurring at this wide range of scales is a major challenge, given that some processes are slowly varying and occur at the basin scale and other processes are rapidly varying and occur at scales of a few meters. In particular, internal waves exist between two frequency limits of the spectrum: the low limit defined by the basin-scale waves and the high limit defined by the buoyancy-frequency.
At the high frequencies (and high wave numbers) of the spectrum the vertical acceleration becomes increasingly significant and the hydrostatic approximation commonly employed to simulate the low-frequency flow field is no longer valid. In order to simulate the lake hydrodynamics throughout this broad range of scales, two complications arise. First, there is a need for high model resolution to resolve the smaller scales of the motion; and second, a fully non-linear and sparse elliptic equation has to be solved to calculate the non-hydrostatic pressure. The main goal of this work was to devise a non-hydrostatic three dimensional model to efficiently compute the motions of lakes at field scales encompassing the whole range of the internal-wave energy spectrum.
At the high frequencies (and high wave numbers) of the spectrum the vertical acceleration becomes increasingly significant and the hydrostatic approximation commonly employed to simulate the low-frequency flow field is no longer valid. In order to simulate the lake hydrodynamics throughout this broad range of scales, two complications arise. First, there is a need for high model resolution to resolve the smaller scales of the motion; and second, a fully non-linear and sparse elliptic equation has to be solved to calculate the non-hydrostatic pressure. The main goal of this work was to devise a non-hydrostatic three dimensional model to efficiently compute the motions of lakes at field scales encompassing the whole range of the internal-wave energy spectrum.
Original language | English |
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Qualification | Doctor of Philosophy |
Awarding Institution |
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DOIs | |
Publication status | Unpublished - 2006 |
Take-down notice
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