Perturbing a magic carpet- Dr Andrew Lawrie (Bristol University)
Internal waves carry more available energy than any other transmission system on earth: lunar diurnal excitation drives 1TW of wave power inside the world’s oceans. Energy is transmitted over thousands of kilometres and individual waves may be hundreds of metres high. Where they break, they deposit their energy, and, in such regions, they greatly enhance the vertical transport of carbon dioxide, oxygen and heat. This talk will explore nonlinear interactions between internal wave beams and their harmonic signatures, using perturbation expansion and singular Green’s function approaches to the problem. Experimental results from a ‘magic carpet’ flexibly-actuated boundary will also be compared with these theoretical predictions, focussing on how nonlinear triadic interactions manifest, how strongly harmonic content influences spatial development of wave-beams, and how wave-breaking events may be triggered.