Abstract
The behaviors of the cloud systems in the tropical Pacific region were analyzed by making use of the spectral method especially paying attention to the lateral propagations of the disturbances. Throughout the analysis, two kinds of disturbances were found : one belongs to the longer period than ten days and another does to the short period with four or five days. The longer period cloud system is estimated to be propagated from the mid-latitude to the equatorial zone at nearly 130-140°W. Such behavior of the long-period disturbance satisfies the theoretical regime of lateral propagation. The shorter period cloud system may be self-induced within the equatorial zone.
