A conundrum in conversion

Abstract

Maintaining the stratification of the ocean requires deep mixing. Part of the energy that provides this mixing is transferred over topography from the surface tides into the internal tides. Numerous theoretical, numerical and experimental studies have aimed at quantifying the energy transfer of this conversion mechanism. Maas (J. Fluid Mech., this issue, vol. 684, 2011, pp. 5-24) constructs model topographies with localized response and no energy transfer into the propagating internal tide, a surprising result that raises questions about models of tidal conversion. © 2011 Cambridge University Press.