MEAN FLOW EFFECTS OF THE LOW-WAVENUMBER PRESSURE SPECTRUM ON A FLEXIBLE SURFACE.

The Lighthill theory is extended so that it may be used to determine the flow noise induced by a turbulent boundary layer over a plane homogeneous flexible surface. The influence of the surface properties and the mean flow on the sound generation is brought out explicitly through the use of a Green function. The form of the low-wavenumber wall-pressure spectrum on a rigid surface with an arbitrary mean flow profile is determined. The effect of a coating layer is investigated.

The QBO, El Niño, and tidal resonance model

I tentatively conclude ... that the QBO may be either modulated or amplified by atmospheric tidal resonances. The generally strong correlation between the QBO and tropical Southern Oscillation, in turn, suggests that one or probably both of these stratospheric and tropospheric oscillations are modulated or amplified by the same tidal-resonance system. ... The strikingly weaker correlation between the Southern Oscillation and El Niño events strongly suggests that some critical parameters are missing in the GCMs specifically designed to predict El Niño occurrence.