Effects of periodic wind forcing on internal seiches over sloped topography

Código

XXVI-SBRH0134

Autores

Rafael de Carvalho Bueno, Tobias Bernward Bleninger, Andreas Lorke

Tema

STE095 - Engenharia Limnológica e Mecânica dos Fluidos Ambiental

Resumo

Internal waves are critical drivers of mixing and ecological dynamics in stratified lakes. While wind-forced internal seiches are well studied, the role of wind periodicity in modulating basin-scale hydrodynamics remains unclear. Through a series of non-hydrostatic numerical simulations in idealized two-dimensional basins, we show that the ratio between the wind forcing period (Tw) and the fundamental internal seiche period (T) plays a pivotal role in shaping boundary layer dynamics and energy dissipation processes. Our results reveal that for Tw/T> 1, the system exhibits enhanced bottom boundary layer (BBL) separation and offshore-directed turbulent jets, promoting elevated turbulent kinetic energy (TKE) dissipation rates, up to three times higher than under supercritical conditions. This regime supports non-resonant forced waves modulated and sustained re-energization of basin circulation and BBL separation. Conversely, when Tw/T< 1, BBL separation is inhibited, and the system transitions to a regime dominated by propagating waves that can shoal and break near sloping topography.