The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY (한국해양학회지:바다)

The Korean Society of Oceanography (한국해양학회)
권호 표지
DOI QR코드

DOI QR Code

Characteristics of the flow in the Usan Trough in the East Sea

동해 우산해곡 해수 유동 특성

  • Baek, Gyu Nam (Ocean Circulation and Climate Research Division, Korea Institute of Ocean Science and Technology) ;
  • Seo, Seongbong (Ocean Circulation and Climate Research Division, Korea Institute of Ocean Science and Technology) ;
  • Lee, Jae Hak (Ocean Circulation and Climate Research Division, Korea Institute of Ocean Science and Technology) ;
  • Hong, Chang Su (Ocean Circulation and Climate Research Division, Korea Institute of Ocean Science and Technology) ;
  • Kim, Yun-Bae (Ulleungdo.Dokdo Ocean Research Station, East Sea Research Institute, Korea Institute of Ocean Science and Technology)
  • 백규남 (한국해양과학기술원 해양순환.기후연구부) ;
  • 서성봉 (한국해양과학기술원 해양순환.기후연구부) ;
  • 이재학 (한국해양과학기술원 해양순환.기후연구부) ;
  • 홍창수 (한국해양과학기술원 해양순환.기후연구부) ;
  • 김윤배 (한국해양과학기술원 동해연구소 울릉도.독도해양연구기지)
  • Received : 2013.10.07
  • Accepted : 2014.03.02
  • Published : 2014.05.28
Download PDF
⟨ Previous Next ⟩

Abstract

One year long time-series current data were obtained at two stations (K1 and K2) located in the Usan Trough in the area north of Ulleungdo in the East Sea from September 2006. The observed data reveal enhanced seafloor flows in both stations with variabilities of about 20 days which is possibly governed by the topographic Rossby wave. After February 2007, strong flow in the upper layer in St. K1 appears throughout the mooring period and this is due to the passage of the warm eddy comparing with satellite sea surface temperature data. During this period, no significant correlation between the current in the upper layer and those in two deep layers is shown indicating the eddy does not affect flows in the deep ocean. It is also observed that the flow direction rotates clockwise with depth in both stations except for the upper of the K1. This implies that the deep flow does not parallel to the isobaths exactly and it has a downwelling velocity component. The possibility of the flow from the Japan Basin to the Ulleung Basin across the Usan Trough is not evidenced from the data.

동해 울릉도 북부의 우산해곡 사면역 2개 정점 K1, K2에서 2006년 9월부터 2007년 9월까지 시계열 해류 자료를 획득하였다. 자료 분석 결과 정점 K1과 K2 모두 심층에서 해저면 유속강화가 관측되었으며, 이 심층 유속장은 20일 주기의 변동성이 강하여 조사해역의 심층 흐름은 지형의 영향을 받은 topographic Rossby wave 현상에 지배되었을 가능성이 크다. 정점 K1의 상층에서 2007년 2월 이후부터 관측된 강한 흐름은 인공위성 관측 해수면온도 자료와 유속 자료상 변화를 비교한 결과 관측 해역에 소용돌이의 통과에 의한 것으로 보이며, 이 기간 동안에 중층과 심층에서의 유속장은 상층 유속장과 상관성이 낮아 소용돌이가 심층의 유동까지 영향을 미치지 않는 것으로 나타났다. 각 정점 유향의 수직구조는 정점 K1 상층을 제외하고 수심이 깊어질수록 유향이 시계방향으로 회전하는 것으로 나타났다. 이러한 유속장의 수직구조 특성은 심층 유동이 정확하게 등심선을 따르지 않고 하향의 수직 유속 성분이 있음을 의미한다. 한편, 우산해곡을 통해 일본분지에서 울릉분지로의 심층 해수 유입의 직접적인 증거는 관측되지 않았다.

Keywords

References

  1. Bryden H.L., 1976. Horizontal advection of temperature for low-frequency motions. Deep-Sea Res. 23: 1165-1174.
  2. Chang K.I., K. Kim, Y.B. Kim, W.J. Teague, J.C. Lee, and J.H. Lee, 2009. Deep flow and transport through the Ulleung Interplain Gap in the southwestern East/Japan Sea. Deep-Sea Res. I, 56: 61-72. https://doi.org/10.1016/j.dsr.2008.07.015
  3. Hamilton P., 1984. Topographic and inertial waves on the continental rise of theMid-Atlantic Bight. J. Geophys. Res., 89(C1): 695-710. https://doi.org/10.1029/JC089iC01p00695
  4. Hogan P.J. and H.E. Hurlburt, 2000. Impact of upper ocean-topographical coupling and isopycnal outcropping in Japan/East Sea models with $1/8^{\circ}$ to $1/64^{\circ}$ resolution. J. Phys. Oceano., 30(10):2535-2561. https://doi.org/10.1175/1520-0485(2000)030<2535:IOUOTC>2.0.CO;2
  5. Kim K, K.R. Kim, D.H. Min, Y. Volkov, J.H. Yoon, and M. Takematsu, 2001. Warming and structural changes in the East (Japan) Sea : a clue to future changes in global oceans? Geophy. Res. Lett., 28(17): 3293-3266. https://doi.org/10.1029/2001GL013078
  6. Kim K, K.I. Chang, D.J. Kang, Y.H. Kim, and J.H. Lee, 2008. Review of Recent Findings on the Water Masses and Circulation in the East Sea (Sea of Japan). J. Oceanogr., 64: 721-735. https://doi.org/10.1007/s10872-008-0061-x
  7. Kim Y.B., K.I. Chang, J.H. Park, and J.J. Park, 2013. Variability of the Dokdo Abyssal Current observed in the Ulleung Interplain Gap of the East/Japan Sea. Acta Oceanol. Sin., 32(1): 12-23.
  8. Park Y.G., K.H. Oh, K.I. Chang, and M.S. Suk, 2004. Intermediate level circulation of the southwestern part of the East/Japan Sea estimated from autonomous isobaric profiling floats. Geophy. Res. Lett., 31: L13213, doi:10.1029/2004GL020424.
  9. Rhines P., 1970. Edge-, bottom-, and Rossby waves in a rotating stratified fluid. Geophy. Fluid Dyn., 1: 273-302. https://doi.org/10.1080/03091927009365776
  10. Sekma H., Y.H. Park, and F. Vivier., 2013. Time-Mean Flow as the Prevailing Contribution to the Poleward Heat Flux across the Southern Flank of the Antarctic Circumpolar Current: A Case Study in the Fawn Trough, Kerguelen Plateau. J. Phys. Oceanogr., 43: 583-601. https://doi.org/10.1175/JPO-D-12-0125.1
  11. Senjyu T., H.R. Shin, J.H. Yoon, Z. Nagano, H.S. An, S.K. Byun, and C.K. Lee, 2005. Deep flow field in the Japan/East Sea as deduced from direct current measurements. Deep-Sea Res. II, 52: 1726-1741. https://doi.org/10.1016/j.dsr2.2003.10.013
  12. Sudo H., 1986. A note on the Japan Sea Proper Water. Prog. Oceanogr., 17: 313-336. https://doi.org/10.1016/0079-6611(86)90052-2
  13. Teague W.J., K.L. Tracey, D.R. Watts, J.W. Book, K.I. Chang, P.J. Hogan, D.A. Mitchell, M.S. Suk, M. Wimbush, and J.H. Yoon, 2005. Observed deep circulation in the Ulleung Basin. Deep-Sea Res. II, 52: 1802-1826. https://doi.org/10.1016/j.dsr2.2003.10.014
  14. Torrence C., G.P. Compo, 1998. A practical guide to wavelet analysis. Bull. Amer. Meteor. Soc., 79: 61-78. https://doi.org/10.1175/1520-0477(1998)079<0061:APGTWA>2.0.CO;2
  15. Uda M., 1934. The results of simultaneous oceanographical investigations in the Japan Sea and its adjacent waters in May and June, 1932. Japan Imp. Fish. Exp. St., 5, 57-190 (in Japanese).
  16. Uehara K, and H. Miyake, 2000. Biweekly periodic deep flow variability on the slope inshore of the Kuril-Kamchatka Trench. J. Phys. Oceanogr, 30: 3249-3260. https://doi.org/10.1175/1520-0485(2000)030<3249:BPDFVO>2.0.CO;2
  17. Yun J.Y., L. Magaard, K. Kim, C.W. Shin, C.S. Kim, and S.K. Byun, 2004. Spatial and temporal variability of the North Korean Cold Water leading to the near-bottom cold water intrusion in Korea Strait. Prog. Oceanogr., 60: 99-131. https://doi.org/10.1016/j.pocean.2003.11.004