Abstract
A survey has been carried out on the spatial and temporal characteristics of slight atmospheric pressure changes concerning the seiches which developed in wide areas of Kyushu in February in 2009. The dominant periods of slight pressure changes are about 100 minutes, and on the other hand, those of seiches depend on local conditions around tidal stations. The time series data of slight pressure changes of some stations are often very similar even if they are distant. By using the characteristics, we estimated the propagation speed and direction of slight pressure changes with FK spectrum analysis. The slight pressure changes propagated almost eastward in conjunction with the passage of the low pressure. The propagation speed of the slight pressure changes is 2.3 km/min and is more than that of the low pressure.
