High-order accurate finite-volume formulations for the pressure gradient force in layered ocean models
Name
Marshall_High-order accurate.pdf
Description
Submitted version
Size
3.26 MB
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Unknown
Checksum (MD5)
8ac1a6b648a0543e1f51468c5356e22e
Author(s)
Engwirda, Darren
Kelley, Maxwell
Marshall, John
Date Issued
August 2017
Journal
Ocean Modelling
Publisher
Elsevier BV
Version
Original manuscript
Abstract
© 2017 Elsevier Ltd Discretisation of the horizontal pressure gradient force in layered ocean models is a challenging task, with non-trivial interactions between the thermodynamics of the fluid and the geometry of the layers often leading to numerical difficulties. We present two new finite-volume schemes for the pressure gradient operator designed to address these issues. In each case, the horizontal acceleration is computed as an integration of the contact pressure force that acts along the perimeter of an associated momentum control-volume. A pair of new schemes are developed by exploring different control-volume geometries. Non-linearities in the underlying equation-of-state definitions and thermodynamic profiles are treated using a high-order accurate numerical integration framework, designed to preserve hydrostatic balance in a non-linear manner. Numerical experiments show that the new methods achieve high levels of consistency, maintaining hydrostatic and thermobaric equilibrium in the presence of strongly-sloping layer geometries, non-linear equations-of-state and non-uniform vertical stratification profiles. These results suggest that the new pressure gradient formulations may be appropriate for general circulation models that employ hybrid vertical coordinates and/or terrain-following representations.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/j.ocemod.2017.05.003
