[A-OS22] Ocean circulation and material cycle in coastal seas

[AOS22-06] The role of ocean circulation on the spatial distribution of SST warming trend in the Japan Sea

*Hiromi Matsuura¹, Shinichiro Kida² (1.Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 2.Research Institute for Applied Mechanics, Kyushu University)

Keywords:Japan Sea, Trend, Spatial Distribution

Sea surface temperature (SST) is a physical parameter that influences the atmospheric field and ocean productivity. The Japan Sea shows a larger SST warming trend than surrounding oceans (Japan Meteorological Agency 2020), and we need to understand its mechanism. The SST trend in the Japan Sea occurs not uniformly in space and shows maxima and minima on a scale of several hundred kilometers from the coast of Korea to the coast of Japan, where the Tsushima Current is located. In this study, we analyzed the location of the SST front and the geostrophic current jet using SST and Sea surface height (SSH) satellite data and examined the role of oceanic circulation on the spatial distribution of SST warming trend.
The SST front and geostrophic current jet showed different behavior in the east and west parts of the Japan Sea. In the eastern part, the mean positions of the SST front and geostrophic current jet were located at similar latitudes and shifted south. This southward movement coincides well with the presence of the minimum in the SST trend. In the western part, on the other hand, the positions of the front and geostrophic jet were about 2° apart, and their meridional shifts were unclear. However, the mean position of the geostrophic current jet overlays the maximum SST trend, indicating the strong influence of oceanic circulation.