2:30 PM - 2:45 PM
[AOS04-04] Geography of the attenuation rates of baroclinic tidal energy estimated using wave-wave interaction theory
Keywords:Internal waves, Baroclinic tide, Resonant interaction
Our approach is basically following the weak turbulence theory, which describes the statistics of energy transfer through wavenumber space caused by weakly nonlinear interactions. It should be noted that our new formulation is applicable to low-mode internal waves, which are strongly subject to the effects of density structure and total depth.
We have calculated the attenuation rate of low-mode baroclinic tidal waves interacting with the background Garrett-Munk internal wave field. The results clearly show the rapid attenuation of baroclinic tidal energy at mid-latitudes caused by parametric subharmonic instability (PSI) which depends on density structures associated with the subtropical gyre, in agreement with field observation and numerical simulation. This study is expected to contribute to clarify the global distribution of the dissipation rates of baroclinic tidal energy.