Normal modes of the Mascarene Basin

In this paper the origin of the bi-monthly variability in the Mascarene Basin is reconsidered. Free oscillatory modes of the Mascarene Basin are determined by performing normal mode analysis on the motionless solution in a barotropic shallow-water model with realistic bathymetry. Several modes are identified with monthly to bi-monthly time scales. The mode that agrees best with recent current meter observations can be interpreted as a barotropic Rossby basin mode, confined to the tilted geometry of the Mascarene Basin.