Speaker 1 :  Ricardo Barros  (Loughborough University)
    Date & Time : October 15th (Fri.), 2021 / 10:00-10:40PM (Tokyo (JST)) 
    Title : Large amplitude mode-2 internal solitary waves in three-layer flows
    Abstract : 
         We consider a strongly nonlinear long wave model for large amplitude internal 
       waves in a three-layer flow bounded above and below by rigid boundaries. 
       The model extends the two- layer Miyata-Choi-Camassa (MCC) model (Miyata 1988; 
       Choi & Camassa 1999) and is able to describe the propagation of long internal 
       waves of both the first and second baroclinic modes. Solitary-wave solutions of
       the model are shown to be governed by a Hamiltonian system with two degrees of
       freedom. Emphasis is given to the solitary waves of the second baroclinic mode
       (mode-2) and their strongly nonlinear characteristics that fail to be captured
       by weakly nonlinear models. In addition to large amplitude mode-2 waves with 
       single-hump profiles, new classes of mode-2 solutions, characterised by 
       multi-humped wave profiles of large amplitude, are also found. The rationale 
       behind the existence of such waves is explained based on the asymptotic limit 
       when the density transition layer is thin. Our analytical predictions based on 
       asymptotic theory are then corroborated by a numerical study of the full 
       dynamical system.