Physical Investigations on the Smoke carried to the City Centre from the Industrial Quarter of Tôkyô on Jan. 22nd, 1936

[摘要] On the morning on the above date the centre of the city of Tôkyô was covered with dense smoke, that was carried there by the weak NE-E wind from the industrial district (called Honjô, the north-eastern region of the city).Fine and quite calm weather throughout the previous night as well as an occurance of an inversion near the ground early in that morning, which occurs very frequently in such a weather, had given rise to the heavy accumulation of smoke in that region.At our observatory the density of the smoke was measured every fifteen seconds by Luxmeter directed to the sun. We obtained the result as shown in fig. 5, from which it became clear that large masses of the smoke A, D, E, F and small fragments B, C, G, H had passed on in the neighbourhood of the observatory. (I=IoAsec ze-ax)Some photographs taken in the midst of the smoke are shown Pl. 10 fig. 2, the minimum visibility being less than 400m.Now, we obtained a very interesting result as to the microvariation of air temperature during the passage of the smoke. If we compare the largely magnified record of temperature with that of wind velocity (anemocinemograph) in fig. 8, we can see that the rate of increase or decrease of the temperature changed suddenly at every minimum point of wind velocity. Their changes are classified into the three cases shown in fig. 9.I. The cases in which the cold mass of the smoke comes at our place. The density of the smoke increases, when the wind begins to blow (cf. Pl. 11 fig. 3 in which the density of the smoke and the record of Dynes' anemograph are shown superposed.)II. The cases in which by the turbulence the cold smoke near the ground is mixed with the warmer air above it, and the density of the smoke decreases.III. The cases in which the warmer air above the smoke layer comes down on the ground, after the smoke has passed away.Under microscope were examined smoke particles received on a glass plate. They aggregate mechanically in most cases, but some of them represent a manner as if they have electric charge (Pl, 12 fig. 4.)The details of my investigations will given in a future number of the Geophysical Magazine published from the Central Meteorological Observatory.

[学科分类] 大气科学