Assessment of Mesoscale Eddy Parameterizations for Coarse Resolution Ocean Models
Abstract
This thesis examines the role of eddies in a 105-year-long basin scale eddy resolving simulation with the MIT GCM. It evaluates the Fickian, the Green-Stone and the Gent-McWilliams parameterizations in a diagnostic study and a series of coarse resolution experiments. The mesoscale eddies in the reference experiment provide a significant contribution to the thermal balance. Specifically designed diagnostic tests show that the horizontal and vertical components of the parameterized flux are not simultaneously downgradient to the eddy heat flux. The transfer vectors are more closely aligned with the isopycnal surfaces for deeper layers. The magnitude of the coefficients is consistent with traditionally used values. However, the eddy heat flux is identified as a complicated process that cannot be fully explained with any of the parameterizations considered. Coarse resolution experiments demonstrate that Fickian diffusion has the least skill in the climatological simulations. The GS and GM schemes perform better. Comparison of the eddy heat flux divergence with the parameterized divergences for typical parameter values demonstrates that the success of the schemes in the climatological simulation is not related to the representation of the eddy heat flux but to the representation of the mixing processes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1999
- Accession Number
- ADA376658
Entities
People
- Mikhail A. Solovev
Organizations
- Massachusetts Institute of Technology