[A-OS14] Physical Oceanography (General)

[AOS14-04] Difference in observed sea-level variabilities between western and eastern side of Fukuoka Bay, Western Japan

*Uehara Katsuto¹, Kei Yufu¹, Naoki Hirose¹, Ayumi Nakaoka², Masumi Shinohara² (1.Kyushu University, 2.Fukuoka Fisheries and Marine Technology Research Center)

Keywords:inner bay, Tsushima Strait, sea level

This study analyzes sea levels observed at the western side of the Fukuoka Bay situated along the southern coast of the Tsushima Strait and focuses on the east-west sea-level differences within the bay, which was conducted by comparing the data with those obtained at Hakata tide-gauge station located on the eastern side of the bay. It was found that that oscillations with a period of 2-3 hours were observed in phase at both sides of the bay, indicating a presence of subtidal oscillation taken place in throughout the bay area. A preliminary result based on an observation from August to December 2023 suggests that sea levels at the eastern side relative to the western side gradually lowers toward winter with magnitudes as large as 20 cm. This seasonal east-west difference in sea levels may have caused by an impact of northerly winter monsoon more effective at the western side because the bay is open to the outer sea along the northwestern side of the bay.