Abstract
The basic data for the tabulations and graphs in this study come from the “Aerological Data of Japan” published by the Central Meteorological Observatory, Tokyo. The values of precipitable water content were computed by the standard method as follows: Σ0.01 q _??_p, where _??_p is the pressure difference (in mb) between the standard levels or the siginificant levels of a sounding. Values of q, specific humidity, were computed by means of the slide rule devised by H. Arakwa. All computations of precipitable water at 11 stations in Japan were made from 1000 mb to 400 mb (about 7 kilometers).
The other table shows the annual variation of a theoretical value of depth of precipitable water, also 1000mb to 400mb, tabulated for the purposes of comparison.
It is also of interest to compare the mean station values in Japan with the monthly mean depths of precipitable water in the United States (U. S. Weather Bureau Technical Paper No.10). The monthly mean depths of precipitable water in Japan are 52.69mm at Shionomisaki (August) and 53.14mm at Tare (August), while the maximum monthly mean depths of precipitable water in the United States are 2.004 inches at Charleston (July) and 1.995 inches at Miami (August).
