A numerical study on the diurnal variation of low-level wind in the lee of a two-dimensional mountain

A series of numerical experiments was made to search for the basic features of diurnal wind variation in the lee of a mountain range using a two-dimensional dry version of the MRI non-hydrostatic model. The features of diurnal wind variation were classified into four regimes according to prevailing wind speed with respect to the characteristic behavior of the lee convergence zone (LCZ). Under moderate prevailing wind, the LCZ propagates downwind far into the leeside plain during the daytime accompanied by a surge of strong wind. This is in qualitative agreement with the daytime advance of downslope wind observed in the Canterbury Plains in New Zealand, and the Kanto plain in Japan.