Séminaire
I have studied spontaneous gravity wave radiation from unsteady vortices in f-plane and spherical shallow water systems. The theory of aeroacoustic sound wave radiation (Lighthill theory) could be extended to shallow water system with the effect of the Earth's rotation. Background in the atmospheric sciences and my previous studies are briefly introduced. I have recently obtained analytical estimate which indicates asymmetry of gravity wave radiation between cyclone and anti-cyclone. The numerical simulation is also performed in an unbouded domain. The results clearly support analytical estimate, in which anti-cyclones radiate gravity wave more intensively than cyclones in finite values of f, sometimes larger than the case of f=0.
seminaires@lmd.polytechnique.fr