General Aspects of Land and Sea Breezes in Western Seto Inland Sea and Surrounding Areas

[摘要] The general aspects of land and sea breezes in western Seto Inland Sea and the surrounding areas are revealed from an analysis of the wind data obtained from the AMeDAS. The study area consists of Kyushu, the western part of Chugoku, and the western end of Shikoku surrounded by the Pacific Ocean, the East China Sea and the Sea of Japan, and the study area contains inland seas both wide and narrow. The day of the land and sea breeze in the study area is specified from the day when the land and sea breeze appears on a coastal area in the middle of the study area. The appearance of unexpected wind directions in the sea breeze situation in that area and the presence or not of the sea breeze in a nearby coastal area of smaller water body are taken into account in the classification of types of the land and sea breeze; this classification results in eight types.The type of sea breeze in both coastal areas is characterized by the developed sea breezes all over the area, except for the northeastern half of the coast facing the Sea of Japan in Chugoku and the eastern end of the Seto Inland Sea. Meeting of the sea breezes in the central region from either side of Chugoku and Kyushu is clearly seen in the afternoon. The other types are discussed and characteristics are compared with this fundamental type. The location of a significant land breeze in northwestern Shikoku is noted in relation to the well-known local gale “Hijikawa-arashi.”The results from the previous study of the relationship between the occurrence of the land and sea breezes and the general meteorological conditions in Osaka Bay and the surrounding areas are shown to hold also for the present area. By coupling the features of the sea breeze in the present study area and those in Osaka Bay and the surrounding areas, the typical features of the sea breeze for a wider area of western Japan are revealed. The interrelation of the behavior of the land and sea breezes in these two areas is also discussed.

[学科分类] 大气科学