Session Ch - Convection & Buoyancy.
ORAL session, Sunday, November 23
308, Moscone Center
Past studies (Townsend 1963, Deardorff 1968) have indicated an important connection between penetrative convection and internal wave motion in an adjacent stratified layer. The rationale behind the present work is to shed new light on the physical mechanisms which govern the transfer of energy between convection and internal waves. Experiments were performed to quantify the existence of a long wave mode in the stratified layer and to illuminate its effect on convective motion. It is hypothesized that individual convective plumes transfer some of their energy to short wavelength internal waves, which can then interact non-linearly to generate long wave motion in the stratified layer. The long wave motion, in turn, is thought to modulate the convective motions, thus closing the feedback mechanism for the energy of the system. Results using a temperature stratified experimental apparatus have shown the existence of this long wave mode, and the effects of the stratification as well as the apparatus length, on wavenumber/frequency selection.