This paper treats the atmospheric smoke pollution in Oosaka observed by an “Air Filter”. This instrument is devised so as to get automatically a continuous record of the amount of sooty suspension in the air. Air is sucked through a small hole across which a sheet of filter paper is transversally moved so that a blackened line of smoke particles (shade) is obtained on it. The observation was continued about a year at two places, Katuyama and Namba in Oosaka. The former place is in the eastern suburb and the observation was made at the Oosaka Branch of Cent. Met. Obs., while the latter is in the central part of the city. The observed shades were estimated hourly comparing with the standard scale of shade. The standard scale was newly made for this investigation by a photometrical method from 0 (perfect white) to 20 (perfect black). This scale is not always linear to the amount of sooty suspension, as the scale 1 corresponds to an amount of 0.08mg per m3, 5 to 0.96 and 10 to 39mg per m3. The main results obtained are as follows:- (i) Annual variation shows a maximum in Nov. and a minimum in May. See Fig. 2. (ii) Hourly variation shows two maxima, one in the forenoon (about 7h) and the other in the evening (about 19h). See Fig. 4. (iii) Sundays and holidays show a little diminution of pollution. (iv) Amount of pollution is on the average twice in the central part compared with that in the suburb. (v) Hourly change of pollution is closely similar at two places. (vi) The pollution diminishes remarkably as the wind velocity increases. (vii) The sun-shine also diminishes the pollution as it causes the convection in the lower atmosphere. (viii) The precipitation surely cleans the atmosphere, but this fact can not be observable so definitely in the air near the surface. (ix) The variation of the smoke-amount according to the wind direction is not so noticeable in the present investigation.
In the eastern part of Asiatic Continent, mainly in the eastern part of Tai-hang Mountains and southeastern part of Khingan Mountains, dust-storms occur frequently and sometimes reach the central part of Japan. They corresponds to the dust-storms in the eastern part of Rocky Mountains in America. Such flying sand particles are called “Kosya”, which means yellow dust, in our country. The dust-storms occur most frequently in spring as in America. In spring many cyclones with fresh cold fronts, along which TA masses are forced to rise by PA masses, are generated in the regions of South Manchoukuo and North China. Very dry sand particles are lifted up to about 4000m by ascending currents caused by cold ronts and carried away with upper air currents of the moving anticyclones whereby the sand particle, descend continuously. The actual falling velocities of sand particles (5μ-25μ) agree with the velocities calculated by the formula of Stokes-Cunningham. The diminution of solar radiation by “Kosya” is on the average30% of the normal day at Hukuoka, about 1400 kilometers of distance from the origin.
In this paper, the author has proved that the energy realisable in the atmosphere by the rearrangement of air masses, initially placed in an unstable manner, cannot be calculated by Margules' method. Further the author has proposed a new method of expressing the degree of unstableness of the air masses of any configuration, using the concept of entropy.