Internal wave scattering in continental slope canyons, part 1: Theory and development of a ray tracing algorithm

Long‐Range Radiation and Interference Pattern of Multisource M2 Internal Tides in the Philippine Sea

“…This is interesting because the interference was usually thought to be a linear superposition of different waves, and the energy flux does not diverge much. However, an intensification of the baroclinic energy due to constructive interference was proven by laboratory experiments (Ghaemsaidi, ) and might cause elevated local mixing (Nazarian & Legg, ; Vlasenko et al, ). The enhanced energy and flux of the beam may create conditions that are favorable for enhanced dissipation by strong vertical shear and nonlinear advection; further direct measurements are required to address this phenomenon.…”

On the Magnitude of Canyon‐Induced Mixing

“…Similarly, the final sensitivity study of Nazarian and Legg (2017a) shows that the spatial extent of instability, and therefore mixing, within canyons scales approximately linearly with length (see Figure 14 of Nazarian & Legg, 2017a). Again, this increase is bounded, as the wavelength of the incoming internal wave also modulates the spatial extent of dissipation (Figure 14c of Nazarian & Legg, 2017a). Therefore, the spatial extent of instability, and thus total energy loss, also scales approximately like the ratio of the canyon length to the wavelength of the incident internal wave.…”

“…Submarine canyons are regions of enhanced levels of internal tide‐driven mixing due to both their geometry and their relative abundance, with over 10% of the continental slope intersected by canyons (Alberty et al., 2017; Aslam et al., 2018; Bosley et al., 2004; Bruno et al., 2006; Carter & Gregg, 2002; Codiga et al., 1999; Gardner, 1989; Gordon & Marshall, 1976; Gregg et al., 2011; Hall & Carter, 2011; Hamann et al., 2021; Hotchkiss & Wunsch, 1982; Kunze et al., 2012; Lee et al., 2009; Nazarian & Legg, 2017a, 2017b; Petruncio et al., 1998; Wain et al., 2013; Waterhouse et al., 2017; Xu & Noble, 2009). Diapycnal mixing within canyons is important for a host of coastal processes (Cacchione et al., 2002; Leichter et al., 2003; McPhee‐Shaw, 2006; Ramos‐Musalem & Allen, 2019), and for the large‐scale circulation of the ocean, as mixing at depth sustains the global overturning circulation (Melet et al., 2016; Munk, 1966).…”

“…In addition to diagnosing dissipative processes, Nazarian and Legg (2017a, 2017b) explored the relationship between the internal wave‐driven dissipation and several geometric and wave parameters (canyon aspect ratio, ζ , canyon height, H , total ocean depth, D , canyon length, L , and the wavelength of the incident internal tide, λ H ). We express the canyon aspect ratio as where W is the canyon width.…”

“… Fraction of the incident internal tide energy loss in two classes of idealized canyons: near‐critical slope canyons (red) and flat bottom canyons (blue) as a function of the aspect ratio, ζ , from Nazarian and Legg (2017a, 2017b). The divergence of the energy flux (diamonds) and turbulent dissipation (circles) are averaged at each value of ζ (squares) and fit with a cubic spline to calculate f ( ζ ) for the global distribution of canyons (dashed line).…”