Japan Sea is generally considered to be one of the places where the most rapid airmass transformation takes place in winter season.As it is surrounded by the dense network of radiosonde and surface observation stations, quantitative investigation about the modification of airmass is possible.Selecting the period of a typical continuous outburst of cold air from 20 Dec.'54 to 3 Jan.'55 during which the air-sea temperature difference exceeded 10°C, we computed the integrated netflux divergence of enthalpy and water vapor and the vertical transport of them at the standard levels in the lower half of the troposphere, and further estimated the amount of heating and cooling due to radiation and condensation.Then, based upon the balance requirement, the amount of heat or water vapor supplied from the sea to the atmosphere was obtained.According to the results of above computations, it is concluded that the amount of supplied heat is as much as 1000ly/day in such a typical unstable situation, and is 2.3 times as large as that of supplied latent heat in spite of the fact that mean Bowen's ratio expected from mixing length theory was nearly equal, to unity.Finally, for several periods when no remarkable cyclone passed over the Japan Sea, the amount of evaporation computed by the scheme above-mentioned are compared with the results obtained by use of climatological evaporation equation after Jacobs.
In order to study the factors which determine the habit of the ice-crystal, a series of experiments on the mode of growth of ice-crystals grown in gases into which water vapor diffuses at different rates have been conducted. In the present paper, results of experiments with air, hydrogen and carbon dioxide are given. In air the mode of growth of ice-crystals at water saturation changes markedly with temperature; at -7°C growth rate along the principal axis is much larger than that along the lateral axis, but at -16°C the former is smaller than the latter. The results of examination of ice-crystals grown at -7°C and -16°C in the gases mentioned above show that the difference in the growth habit with temperature as mentioned above is pronounced in the case of carbon dioxide as in the air, but much less pronounced in the case of hydrogen atmosphere. In hydrogen gas the growth velocities in both directions are nearly equal. This tendency was found in the mode of ice-crystals formed by two different methods; one formed by AgI seeding and the other formed on rabbit hair in a cold chamber. In the latter case, air and hydrogen were filled in the chamber by turns during the growth of an ice-crystal and the corresponding changes in the modes of growth were observed.
The relation between the atmospheric electric field and the coefficient of eddy diffusivity is discussed under the following assumptions: i) The vertical distribution of the space charge is controlled by eddy diffusion near the ground. ii) The space charge transported into a unit volume of the atmosphere by eddy diffusion is balanced by the space charge dissipated by the atmospheric electric conductivity in the same unit volume. Using the observed results of the atmospheric electric field, conductivity and space charge obtained at Hongo, we estimate the diurnal variation of the coefficient of eddy diffusivity in each season. The value is 5.0×104cm2/sec in the daytime and 5×103cm2/sec at night.
The content of radioactive substances in the atmosphere near the ground was measured in Tokyo, and the mean value is 0.9×10-16 curie/cm3 in the daytime and 2.3×10-16curie/cm3 at night. Using these observed values and the coefficient of eddy diffusivity estimated from the method of atmospheric electricity described in the previous paper(1), we calculated the hourly values of the content of radioactive substances. The rate of ion pair production by the α ray emitted by the radioactive substances in the atmosphere is estimated. The earth radiation was measured, and ion pair production by that is (3.0±0.1) J. Using these data, the rate of total ion pair production in the atmosphere are estimated.
In this paper, the total energy of waves raised in a typhoon was estimated, and it was investigated what percentage of the wind energy dissipated by the surface friction is needed for the formation of waves. Moreover, the author constructed several maps showing the mean distribution of wind waves, swell and wave steepness in a typhoon, and discussed the characteristics of them. Some descriptions were made on the relation between the wind velocity and the wave height or period, and on the relation between the wave steepness and the wave age. Furthermore, on the basis of wave energy spectra at the Port of Onahama obtained by Ijima, the author discussed the distribution of wave energy spectrum in a typhoon progressing on the open sea.