Residual circulation due to internal waves shoaling on a slope
Limnol. Oceanogr., 55(3), 2010, 1009-1023 | DOI: 10.4319/lo.2010.55.3.1009
ABSTRACT: We describe the residual circulation induced in a two-layer system when internal waves, with a wave length equal to or longer than the slope length, propagate over a sloping bottom and either reflect or break. For the case of no wave breaking, scaling is used to derive Boussinesq-type equations, the solution of which leads to an expression for the residual circulation adjacent to the sloping bottom. This residual circulation is maintained by a weak slope on the density interface. For breaking waves, laboratory experiments and numerical modeling were used to ascertain the details of the residual circulation arising from the formation of gravitational intrusions. Results from these three investigative tools were used to determine, as a function of bottom slope and incident wave amplitude, the internal wave reflection coefficient and the strength of the residual circulation pattern with and without wave breaking.