Strongly nonlinear internal solitons: Models and applications

A strongly nonlinear evolution equation based on an approximate Hamiltonian is suggested and applied to the description of nonstationary processes of formation and evolution of strong internal solitons and their groups (solibores). Comparison with experimental data shows that such a simplified approach can be effectively applied to the description and prediction of strong internal waves' evolution in the upper ocean. Plain Language Summary In the nature, nonlinear solitary waves (we call them solitons notwithstanding their formal definition) most commonly exist in the form of internal gravity waves in the ocean where the internal solitons are ubiquitous and practically important. They are especially typical of shelf zones where nonlinear internal waves (IWs) are generated by tidal currents incident on the shelf slope, as well as in deeper regions with an expressed seasonal pycnocline. Single solitary waves as well as groups of solitons dubbed "solibores" are generated in these areas. The number of observations of strong internal waves including solitons in both shelf areas and upper layer of the deep ocean is increasing fast. We suggest a theoretical model (evolution equation) for these processes and compare it with oceanic observations.