Internal wave generation in a global baroclinic tide model

Abstract

The energy flux out of barotropic tides and into internal waves (‘‘conversion’’) is computed using a global domain multi-layer numerical model. The solution is highly baroclinic and reveals a global field of internal waves radiating way from generation sites of rough topography. A small number of sites where intense internal wave generation occurs accounts for most of the globally integrated work done on the barotropic tide and dominates sites such as the Mid- Atlantic ridge. The globally integrated conversion of the M2 barotropic tide is 891 Gigawatts and the globally integrated rate of working of the ocean by astronomical forcing is 2.94 Terawatts. Both of these estimates are close to accepted values derived from independent methods. Regional estimates of conversion are also similar to previous inferences, lending additional confidence that the solution has captured the essential physics of low-mode internal wave generation and that numerical prediction of conversion has skill in regions where no previous estimates are available.