Analysis of the Energetics of mode-1 internal waves interacting with topographic ridges of varying slope and height

This research presents a detailed analysis of 40 two-dimensional high-resolution computational fluid simulations as part of a parametric study examining the interaction and energetics of mode-1 internal waves with oceanic ridges. The main parameters are internal wave forcing velocity amplitude, U₀, ridge height, h and ridge slope, γ. Flows initialized with a high Froude number (Fr=U0/c_ph, where c_ph is internal wave celerity) show results with increased turbulence, dissipation and non-linear structures such as internal boluses. Energy flux budget analysis shows that ridges with critical slopes concentrate internal wave beams upon interaction with the topographic ridge, resulting in increased turbulence. When ridges are characterized by super-critical slopes and a large ridge height more wave energy is reflected, while more energy is transmitted by ridges with a small topographic height and/or subcritical slopes. Without explicit resolution of all turbulent scales non-linear structures that are important for understanding these types of flows can be realistically modeled. Analysis of these interactions at intermediate scales (~100 m), below the field scale (≥1000 m) and above the laboratory scale (≤10 m) is not currently present in the literature allowing for this work.The utility of fundamental process models used in informing physically realistic models and field measurements are presented to improve understanding and prediction of mixing in stratified geophysical flows.