Abstract / Description of output
We derive simplified balanced equations by introducing perturbation expansions in the variational principle of a low-order fluid model and in that of the rapidly rotating shallow-water equations. In the case of the shallow-water equations, this provides a constrained variational principle for the barotropic quasi-geostrophic equations which is based on the Lagrangian description of the fluid. Our results thus show that the quasigeostrophic equations can be derived systematically in the context of Lagrangian variational principles.
Original language | English |
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Pages (from-to) | 67-79 |
Number of pages | 13 |
Journal | Geophysical and astrophysical fluid dynamics |
Volume | 88 |
Issue number | 1-2 |
Publication status | Published - 1998 |
Keywords / Materials (for Non-textual outputs)
- Lagrangian variational principle
- Rossby-number expansion
- quasi-geostrophic equations
- MANIFOLD