The stability of internal gravity waves in a bounded atmospheric shear layer in the presence of moisture

Abstract

The stability characteristics of internal gravity waves, generated by an isothermal bounded tangent velocity profile in the presence of a saturated finite layer, are studied. The moist layer with constant thickness the structure of the ness is introduced at different levels in respect to the point of inflection and the variations of moisture content and distance from the origin are examined. The characteristics of the unstable waves are obtained by solving numerically the linearized versions or the full equations of motion, in the inviscid and Boussinesq limit, through the technique of Lalas and Elnaudi (1976).

 It is shown that the presence of the moist layer can significantly affect the stability characteristics of the waves. Increases in the moisture and distance of the layer from the Inflection point are found to amplify or decay the wave response, because the saturated layer behaves as a solid boundary to the flow. The presence of such effective layer is shown to stabilize short wavelengths and destabilize. Finally, an application of the model's results to the real atmosphere is discussed.