On some homogenization problems from shallow water theory

This note is devoted to the effect of topography on geophysical flows. We consider two models derived from shallow water theory: the quasigeostrophic equation and the lake equation. Small scale variations of topography appear in these models through a periodic function, of small wavelength εε. The asymptotic limit as εε goes to zero reveals homogenization problems in which the cell and averaged equations are both nonlinear. In the spirit of article [P.-L. Lions, N. Masmoudi, Homogenization of the Euler system in a 2D porous medium, J. Math. Pures Appl. (9) 84 (1) (2005) 1–20], we derive rigorously the limit systems, through the notion of two-scale convergence.