Breaking Location of Internal Solitary Waves Over a Sloping Seabed

Abstract

Internal solitary waves (ISWs) consist of hump-shaped large undulations of the pycnocline with a permanent form, resulting from a balance between nonlinearity, which tends to steepen it, and dispersion, which tends to flatten it (Grimshaw et al., 2010; Helfrich & Melville, 2006; Sutherland et al., 2013). ISWs are mostly generated by the interaction between tidal flows and bottom topographic features, such as underwater sills and the continental shelf-slope region (Helfrich & Melville, 2006; Osborne & Burch, 1980). Packets of shoreward-propagating ISWs, separated by tidal periods, are a ubiquitous feature of the coastal oceans (Dwi

Mid-to-late Holocene upper slope contourite deposits off Capo Vaticano (Mediterranean Sea): High-resolution record of contourite cyclicity, bottom current variability and sandy facies

“…The modified-LIW is a salty vein (38.5, T of ~14.3 • C), flowing geostrophically northward, in between the TSW and the tidal branch of LIW. The origin of this modified-LIW was hypothesized by Marullo and Santoleri (1986) as the result of mixing processes, occurring at the sill region during the "rema montante", as well as resulting from the breaking of internal solitary waves (La Forgia et al, 2018;Cavaliere et al, 2020). These particular non-linear internal waves (i.e., solitons) are one of the most peculiar features of the area: they generate at the Strait of Messina due to the hydraulic jump occurring during the strong tidal forcing and propagate northward at the interface between the LIW and the TSW, reaching the frontal slope of Capo Vaticano (Fig.…”

Mixing Efficiency for Breaking Internal Solitary Waves

“…However, seafloor‐induced turbulence is expected to occur within the bottom boundary layer. This suggests that internal waves are likely responsible for transport energy up from the bottom, due to their interaction with bathymetric features such as seamounts, sills, ridges and continental slopes (Cavaliere et al., 2021; Polzin et al., 1997).…”

“…In general, to quantify mixing, all experimental and numerical studies we briefly summarized above analyze the evolution of density and velocity fields. Here, through the Ozmidov and Thorpe lengthscales, we develop a novel expression for the mixing efficiency, valid for plunging, and plunging‐collapsing breakers, that is, the breakers type mostly expected in the continental shelf region (Cavaliere et al., 2021; La Forgia, Adduce, & Falcini, 2018). By means of experimental results, we relate the mixing efficiency derived by our heuristic model with the one obtained by a canonical, theoretical definition.…”

“…Near‐bed instabilities and shear stress, associated with strong currents beneath ISWs, trigger sediment resuspension (Boegman & Stasna, 2019; Bogucki et al., 1997). As a consequence, solitons may play an important role in shaping the seafloor, by transporting sediment in both the downslope and upslope directions (Cacchione et al., 2002; Cavaliere et al., 2021; Martorelli et al., 2020; Puig et al., 2004), and generating peculiar sediment patterns (Droghei et al., 2016; La Forgia, Adduce, Falcini, & Paola, 2019).…”

Numerical Simulation for the Evolution of Internal Solitary Waves Propagating over Slope Topography

“…The evolution characteristics of internal solitary waves on slope topography have been studied extensively using experiments and numerical simulations aimed at changing the wave profile and flow field characteristics [15][16][17][18][19][20][21][22]. The breaking types of ISWs are studied using experiments and numerical simulations aimed at changing the wave profile and flow field characteristics [23][24][25]. However, ISWs can propagate over mild slopes without breaking, such as fission, polarity reversal, and the formation of trailing waves.…”