Author(s): Moonock Lee; Shinya Otake; Myeongwon Kim; Jonghwan Yoon; Jongkyu Kim
Linked Author(s):
Keywords: Cold water; Ulsan coastal waters; NGSST satellite image; Tsushima Current; Liman Current
Abstract: We conducted field observations, satellite image data analyses, and numerical simulations to understand the cause for the appearance of cold water (CW) in the summer in the eastern coastal areas of Korea. CW in abnormal years approached shallower areas, so the water temperature tended to be lower, compared to that during normal years. This suggested that CW develops and extends to coastal waters in abnormal years to a greater extent than that in normal years. The numerical simulation results of the currents well explained the observational results of water temperature in terms of geostrophic currents. In normal years, the Liman Current (LC) extended or retreated to the northern tip of the western coast of the Japan Sea. However, it remained at the northwestern tip of the Japan Sea, thereby balancing the Tsushima Current (TC). In abnormal years, the LC gradually extended to the south, so that most of the Japan Sea, including the eastern areas of the Korean Peninsula, was brought under the power of the LC. As a result, the appearance of CW in the summer in the western coastal areas of the Japan Sea was a side effect of the extension of the LC southward. Computational results for Ulsan Coastal Waters, when the summer southerly wind blew, showed reverse currents between the surface and bottom layers. Consequently, we noticed that an upsurge in CW can occur in the summer in the neighborhood of Bangeojin, which has rapidly varying topography.
Year: 2013