Internal tides variability at steep topographies: Interactions and probabilistic global dynamical analysis

Internal tides and waves are important drivers of mixing and transport in the coastal ocean. In this work, we investigate the spatial variability, temporal variability, and intermittency of internal tides using non-hydrostatic simulations at idealized steep topographies. In particular, we study the sensitivity of internal tide generation and propagation to variability in the external forcing and background state. Examples of such variability include variations in the remote barotropic and internal tides forcing, background stratification, background flow, and surface wave forcing. To complete such studies, we employ a novel probabilistic global dynamical analysis using the stochastic Dynamically Orthogonal (DO) non-hydrostatic Boussinesq equations. These equations, where the stochasticity is introduced through the remote forcing, surface forcing, and background state, evolve in a fully coupled way the mean flow, density, and waves, as well as the statistical, spatial, and temporal characteristics of the stochastic fluctuations. The resulting global analysis also allows the study of nonlinear energy transfers and of the degree to which internal tides respond to specific variable forcing.