Abstract
The periodical oscillations contained in time variations of meteorological elements at five weather stations in the extratropical and subtropical regions of Japan were examined by spectrum analyses. The meteorological elements were air temperature, pressure, wind, total cloud amount, and flux of global solar radiation in 1977. The analyses showed that about 30-day and 50-day period mode oscillations, and about 40-day period mode oscillation appeared persistently in the time variations in the extratropical and the subtropical region, respectively. In addition, about 70-day period mode oscillation was sometimes seen in both regions, but we cannot determine from the present analyses whether or not a disturbance with a period of about 70 days is definitely existent. Comparison of time variations among the elements at a station indicated that the time variations were associated with each other and the phenomenon was concurrent. It is suggested that the time variations are accompanied by some large-scale tropospheric oscillation. The present study gives a positive support to the existence of about 30 to 50-day period oscillation around Japan.
