Abstract
In considering ocean resource development and disaster reduction in Japan, it is necessary to grasp the ocean environment around Japan, and analyses of the ocean condition such as the current structure and the change of water temperature. Therefore, in this study we analyzed the ocean environment for Japan Sea using the reanalysis data FORA-WNP30, which contains long-term (30 years), high frequency (daily) and high-resolution (1/10 degree) data. The reproducibility of water temperature and salinity in Japan Sea from FORA-WNP30 were evaluated and accuracy of the data was confirmed. Then, in order to grasp the ocean environment of Japan Sea, changes of water temperature and water flux at the straits of Japan Sea were analyzed. As a result, increasing trend of water temperature is large from sea surface to 300 m water depth in Japan Sea, being particularly conspicuous in autumn. The flux of each strait in Japan Sea have peak frequency at half and 1 year, respectively. The fluxes at Tsushima, Tsugaru and Soya strait are highly correlated. Because Liman cold current affects flux at Mamiya strait, the flux correlation with other straits is small.
