On the Amount and Magnitude of the Dust Particles suspended in the Atmosphere over Tokyo

Abstract

In the present paper the transmission coefficients due to the dust, c and x, in the expression _??_ as adopted by Angstrom, were computed by the method of numerical integration. The data used were taken from the results of observation made by Dr. Yazaki and his collegues with the Linke-actinometer provided with two Schott filters, OG1 and RG2, in Zikei college of medicine during the interval from May 1933 to June 1934.
The principal facts deduced from the statistical investigation of the results of this computation are as follows: The atmospheric condition, so long as we have regard to the dust only, in worst in winter, owing to the abundance of the smoke ejected from the chimneys of government officies, companies and other buildings, and is comparatively good on Sunday. The turbidity varies with the velocity and direction of wind. It is large in the calm weather, and becomes minimum in 2_??_3m/sec, and maximum again in 5_??_8m/sec, and then gradually decreases according to the increase of velocity. It is least in the case of the southerly wind.
It was suggested that the extinction of dust might not be expressed by the simple formula _??_ alone, in the local, exceptionally turbid atmosphere such as is above Tokyo.