Effect of latent heat release on mountain waves in a sheared mean flow

Abstract

ABSTRACT. The effect of latent heat release on windward side of the mountain due to precipitation over the mountain waves has been studied assuming wind speed changing with respect to height. A  single profile based on actual Peshawar data has been considered for the analysis. A thin level of heating has been chosen at medium level for the purpose of study. For non-hydrostatic case it is observed that in non-precipitation case when balanced heating/cooling takes place on the windward/leeward side or the mountain the effect of heating is negligibly small. However, for precipitation case downward displacement on the windward side, just above the level of heating. is obvious. Interference with the upstream current by the waves, produced due to elevated thermal forcing and reflected from the around surface is attributed to this phenomenon. Increase in the wave amplitude on the lee-side of the mountain as compared to non-precipitating case is also found. It is also revealed that higher the level or heating lesser the amplitude of the induced disturbance. 4.5 km agl is the level which is maximum affected by heating in general.

For large and shallow mountainous terrains. hydrostatic solutions have been produced for three different levels of heating for sheared flow, Streamlines have been drawn. On comparison with no shear case, it may be inferred that shear effect is opposite to that due to thermal forcing.