The changes of energies of the mean flow with the vertical and horizontal shears and a superimposed disturbance are discussed, using the quasigeostrophic vorticity equation. Stability properties of the simple baroclinic atmosphere which is made up from the northern hemispheric data after Starr and White (1954) are investigated by means of the so-called “energy method ”. The direction of the energy flow is examined for various ranges of the disturbance wave length. It is found that amounts of increase of the kinetic energy of the mean flow due to non-linear interaction seem to be sufficient to overcome those which are continuously exhausted within the friction layer near the ground. The unstable baroclinic disturbance tends to produce the poleward and upward transport of sensible heat, and simultaneously the intensity of the zonal current is strengthened by concentration of eddy zonal momentum due to the presence of the latitudinal variation of the mean flow.
The mixing length theory has been extended to cover the non-neutral conditions, and basing on it the expressions for the velocity profile applicable to conditions of any degree of stability have been derived. It was shown that the theoretical profiles agree fairly well with the observed profiles due to Rider. At the same time comparison with Rider's observations has revealed some defects of the theory, which seem to be due to neglection of the effects of radiative transfer in the present theory.
Microscopic observation was carried out for the sublimation process of snow crystals covered with plastic replica film. It was confirmed that the thermal etch pits were formed on the surface of snow crystals during this process together with the sublimation from the rim of the crystals. The shape of the etch pits is reasonable in view of the crystal axis. The chemical etching of snow crystals was observed by keeping them in kerosene for three months. bservation of the thermal and chemical etching shows that the plane snow crystal developed from one center nucleus is a single crystal.