Abstract
This short note gives the results of comparison of the solar radiation intensity observed at the central meteorological observatory of Japan with that at the Tiba Hygenic Colledge situated at a marginal part of Tiba, a country town some 30km distant from Tokyo due northeast. The comparisons have been made only for the total radiation in the cases when there was no spec of cloud over the sun's disk. The series of the simultaneous observations taken in this investigation extends over the three months, August, September and November of 1931. The radiation intensity at Tokyo was found to be remarkably below that at Tiba, with a few exceptions. The extinction came out, in the mean, 0.44 for Tokyo and 0.34 for Tiba. The general tendency is the same throughout day time, but the contrast is most marked in the later morning hours and afternoon being temporarily diminished by noon. Medium wind velocity at Tokyo tends to diminish the contrast of the atmospheric conditions of the two stations. No definite relation of the contrast to the wind direction has been found to exist, but there seems to be a slight tendency that northerly winds at Tokyo favour greater contrast.
