|Modeling ocean circulation on unstructured meshes: comparison of two horizontal discretizations|
|Danilov, S.; Wang, Q.; Losch, M.; Sidorenko, D.; Schröter, J. (2008). Modeling ocean circulation on unstructured meshes: comparison of two horizontal discretizations. Ocean Dynamics 58(5-6): 365-374. dx.doi.org/10.1007/s10236-008-0138-5|
|In: Ocean Dynamics. Springer-Verlag: Berlin. ISSN 1616-7341, more|
Baroclinic motion; Finite element method; Ocean models; Oceanic circulation; Marine
|Authors|| || Top |
- Danilov, S.
- Wang, Q.
- Losch, M.
- Sidorenko, D.
- Schröter, J.
Finite-element models on unstructured meshes are frequently formulated in terms of continuous linear elements, which suffer from pressure modes and require stabilization. Alternatively, horizontal velocities may be represented with linear nonconforming elements. While the latter formulation uses three times more degrees of freedom for the velocity, it does not support pressure modes. The effects of stabilization are estimated by comparing the performance of continuous linear and nonconforming versions of the finite-element ocean circulation model (FEOM) in two simple configurations: a Munk gyre and baroclinic turbulence in a zonally reentrant channel. It is shown that, outside the free slip boundary layers, the presence of stabilization does not lead to noticeable effects if its strength is kept within certain limits. In order to evaluate the performance of FEOM, the baroclinic turbulence test is repeated with the MIT general circulation model (MITgcm), which serves as a benchmark, and reasonable agreement between different model codes is found. The two versions of FEOM have a similar computational cost, but both are significantly slower (per node) than the regular-mesh MITgcm. The paper also provides a brief description of the implementation of the nonconforming version of FEOM.