Internal solitary waves of elevation advancing on a shoaling shelf

[1] A sequence of three internal solitary waves of elevation were observed propagating shoreward along a near-bottom density interface over Oregon’s continental shelf. These waves are highly turbulent and coincide with enhanced optical backscatter, consistent with increased suspended sediments in the bottom boundary layer. Nonlinear solitary wave solutions are employed to estimate wave speeds and energy. The waves are rank ordered in amplitude, phase speed, and energy, and inversely ordered in width. Wave kinetic energy is roughly twice the potential energy. The observed turbulence is not sufficiently large to dissipate the waves’ energy before the waves reach the shore. Because of high wave velocities at the sea bed, bottom stress is inferred to be an important source of wave energy loss, unlike near-surface solitary waves. The wave solution suggests that the lead wave has a trapped core, implying enhanced cross-shelf transport of fluid and biology.