In the present article, the frequency distribution function of velocities in turbulent flow is derived by the theory of random walk, on the asumption that the phases of elementary waves are at random and independent with each other. The normal distribution is obtained for the frequency of velocity fluctuations as the first approximation. The second approximation is also obtained. As the number of elementary waves increases, the distribution tends to the normal distribution asymptotically. The frequency distribution of the velocity has a modified form of the normal distribution.
Forecasting of precipitation is discussed with the same idea of integrated atmosphere. As the precipitation is expressed by continuty equation, we integrated it by use of mean value theorems and found that the precipitation is shown approximately by following formula. Where m: amount of precipitation per unit time and unit area, σ*: mixing ratio on the 700 mb surface, Q*: velocity divergence on the 700 mb surface. Q: velocity divergence on the 500 mb surface. And we tried to explain using above formula the synoptic situation and compared the calculated rain with the observed one.
Ice crystals produced by seeding of silver iodide, its nuclei and nuclei of ice crystals produced by dry ice seeding were observed with an electron-microscope. The process of ice crystal formation is discussed.