Journal of Oceanography, Vol. 65 (No. 1), pp. 17-29, 2009
Jae-Hong Moon1*, Naoki Hirose2, Jong-Hwan Yoon2 and Ig-Chan Pang3
1Department of Earth System Science and Technology, Interdisciplinary Graduate School of Engineering Science, Kyushu University, Kasuga-Koen, Kasuga 816-8580, Japan
2Research Institute for Applied Mechanics, Kyushu University, Kasuga-Koen, Kasuga 816-8580, Japan
3Department of Oceanography, Cheju National University, Jeju 690-756, Korea
(Received 21 December 2007; in revised form 18 July 2008; accepted 20 July 2008)
Abstract: Recent investigation suggests that volume transport through the Tsushima/Korea Strait often has double peaks during the summer to autumn period with decreasing transport in September. The satellite-observed wind changes from weak northwestward (across-strait) in summer to strong southwestward (along-strait) in early autumn (September) in the strait. Such a strong along-strait wind is related to tropical cyclones, which frequently pass through the East China Sea in September. The effect of the along-strait wind component on the transport variation is examined using a three-dimensional numerical model. The simulated volume transport through the Tsushima/Korea Strait shows realistic seasonal and intra-seasonal variations. According to sensitivity experiments on local winds, the transport variations in September are mainly generated by strong along-strait (southwestward) wind rather than weak across-strait wind. The strait transport responds to the along-strait wind (southeastward), which produces a sea level increase along the Korean coast, resulting in the geostrophic balance across the strait. The transport minimum through the Tsushima/Korea Strait in September can be determined by the combination of the across-strait geostrophic and along-strait ageostrophic balances.