Long-wave decay due to convective turbulence

Long waves are generated in a laboratory-size rectangular basin, which is heated uniformly from below. Their subsequent decay is measured, and the decay component due to the action of convective turbulence isolated, using a combination of existing theories and interpretation techniques. An expression is proposed for the turbulent decay decrement as a function of the bulk Rayleigh number. The results agree as well as can be expected with a simple model based on a Reynolds-stress decay estimate obtained by superposing convective thermals on the oscillating flow associated with the long wave.