Publication Date
8-2024
Date of Final Oral Examination (Defense)
6-12-2024
Type of Culminating Activity
Dissertation
Degree Title
Doctor of Philosophy in Computing
Department Filter
Computer Science
Department
Computer Science
Supervisory Committee Chair
Micha Kopera, Ph.D.
Supervisory Committee Member
Donna Calhoun, Ph.D.
Supervisory Committee Member
Ellyn Enderlin, Ph.D.
Abstract
Ocean models often employ the hydrostatic assumption for large-scale applications when the horizontal scale is larger than the depth. Nonetheless, the non-hydrostatic effects are of great importance in submesoscale studies, such as modeling the physical processes of ice-ocean interactions. Most non-hydrostatic ocean models used in ice-ocean interaction studies are low-order finite-difference and finite-volume methods, often with significant dispersive errors. Therefore, there is a need for a high-order ocean model for ice-ocean interaction applications.
The first part of this thesis focuses on deriving the boundary conditions at the ice-ocean interface and incorporating them into the high-order discontinuous Galerkin (DG) method-based ocean model, the Non-hydrostatic Unified Model of the Ocean (NUMO). This coupling empowers the NUMO model to be used by climate scientists to conduct accurate simulations of ice-ocean interactions. We provide evidence of NUMO's precision in capturing small-scale processes at the ice-ocean interface and validate our findings with published results. This work provides an understanding of how the interaction between ice and ocean can lead to changes in basal melting, which has significant implications for the calving of the ice sheet and ocean circulation within the fjords in Greenland.
In the second part of the thesis, we develop a high-order unstructured DG-based hydrostatic model using multilayer shallow water equations for large-scale applications. We derived and developed high-order numerical schemes based on the nodal DG method. We demonstrate the correctness and accuracy of the model on well-balance and perturbation of baroclinic wave propagation problems. We validate our model through a comparison with the HYbrid Coordinate Ocean Model (HYCOM) for wind-driven double-gyre circulations in different configurations. Our hydrostatic model produces accurate results and resolves more dynamic features at the same resolution as in HYCOM as we increase the polynomial order approximation. We show that this model can be used to study large-scale ocean systems, enabling multi-dynamics simulations and improving the accuracy of ocean forecasts.
DOI
https://doi.org/10.18122/td.2235.boisestate
Recommended Citation
Gahounzo, Yao, "Multi-Scale Ocean Modeling Using the Discontinuous Galerkin Method" (2024). Boise State University Theses and Dissertations. 2235.
https://doi.org/10.18122/td.2235.boisestate
Comments
https://orcid.org/0000-0001-8178-4887