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

The Korean Society of Oceanography (한국해양학회)
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Stratification and Destratification Processes in the Kangjin Bay, South Sea, Korea

남해 강진만에서 성층 형성과 성층 파괴 과정

  • Jung, Kwagn-Young (Department of Oceanography, College of Natural Sciences, Chungnam National University) ;
  • Ro, Young-Jae (Department of Oceanography, College of Natural Sciences, Chungnam National University)
  • Received : 2010.05.13
  • Accepted : 2010.08.18
  • Published : 2010.08.31
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Abstract

This study analyzed stratification and destratification processes in the Kangjin Bay (KB), South Sea, Korea, driven by the Nam Gang Dam water discharge based on numerical modeling experiments. Model performances were evaluated in terms of skill scores for elevation, velocity, temperature and salinity, with scores mostly exceeding 90%. The models reproduced the tidal current, density-driven and wind-driven current. The stratification by fresh water input and destratification by the wind mixing was assessed in terms of the characteristic Richardson number (Ri) in that Ri increased from 0 to 7~20 during the Dam water discharge period, while vertical mixing and destratification followed by the typhoon passage showed Ri, 0 to 2.

하계 남강댐 방류수 유입에 의해 강하게 성층화된 남해 강진만에서 3차원 수치모델링 실험을 통해 태풍 통과시 염분장에 미치는 취송류의 영향과 성층 파괴에 대해 연구하였다. 조위와 유속장, 수온장, 염분장에 대해 각각 스킬 분석(skill analysis)을 이용하여 모델을 검증 하였고, 그 결과 대부분 90%가 넘는 재현율을 보였다. 모델은 조류, 담수유입에 의한 밀도류와 바람에 의한 취송류를 잘 재현했다. 대량 담수 유입이 있을 경우 바람의 영향은 강한 밀도류에 의해 상대적으로 큰 효과가 없으나, 담수유입이 감소하는 시기에는 바람이 수직 혼합작용을 촉진하여 바람을 부과하지 않은 모의 실험보다 2~3일 빠르게 성층을 파괴하였다. 담수 유입에 의한 성층과 바람에 의한 성층 파괴는 성층지수(Richardson 수(數), Ri)를 통하여 판단하였으며, 대량 방류시 성층지수는 급속도로 증가하여 Ri 수(數)가 7~20을 보였고, 방류가 중단된 이후에는 바람에 의한 혼합으로, 성층지수는 급격하게 감소하고 Ri 수(數)는 0~2까지 보였으며, 이 때 상하층간 염분은 일정하게 분포하였다.

Keywords

Acknowledgement

Supported by : 충남대학교

References

  1. 노영재, 2006. 피조개 양식어장의 인터넷 환경 자동감시 및 생산량 산정. 해양수산부, 155 pp.
  2. 정광영, 2007. 남해 강진만에서의 바람과 담수 유입에 의한 하계 해수순환 수치모델링, 석사학위청구논문, 충남대학교, 130 pp.
  3. 한국해양연구소, 1996. 한반도 주변 조석 조화 상수 자료집. 282 pp.
  4. Blumberg, A.F. and G. Mellor, 1987. A description of three dimensional coastal ocean model. In: Heaps N (de) Three dimensional coastal ocean model. American Geophysical Union, Washington DC.
  5. Blumberg, A.F., 2002, A Primer for ECOMSED, Hydroqual Inc.,188 pp.
  6. Cai, S., Q. Huang and X. Long, 2003. Three-dimensional numerical model study of the residual current in the South china Sea. Oceanol. Acta, 26(5): 597-607. https://doi.org/10.1016/S0399-1784(03)00053-7
  7. Carballo, R., G. Iglesias and A. Castro, 2009. Residual circulation on the Ria de Muris (NW Spain): A 3D numerical model study., J. of Marine Sys. 75(1-2): 116-130. https://doi.org/10.1016/j.jmarsys.2008.08.004
  8. Dube, S.K., Rao, A.D., Shinha, P.C. and Jain, I., 1995. Implications of climatic variations in the fresh water outflow in the windinduced circulation of the Bay of Bengal. Atmospheric Env. 29(16): 2133-2138. https://doi.org/10.1016/1352-2310(94)00238-G
  9. Geyer, W.G, 1993. The importance of suppression of turbulence by stratification on the estuarine turbidity maximum. Estuaries 16(1):113-125. https://doi.org/10.2307/1352769
  10. Gong, W, Shen, J. and Hong, B., 2009. The Influence of wind on the water age in the tidal RappahannockRiver. Marine Env. Res., 68: 203-216. https://doi.org/10.1016/j.marenvres.2009.06.008
  11. Goodrich, D., Boicourt, W., Hamilton, P. and Pritchard, D., 1987. Wind-induced destiatification in Chesapeake Bay. J. of Phys. Oceanogr., 17: 2232-2240. https://doi.org/10.1175/1520-0485(1987)017<2232:WIDICB>2.0.CO;2
  12. Guo, X. and Valle-Levinson, A., 2008. Wind effects on the lateral structure of density-driven circulation in Chesapeake Bay. Cont. Shelf Res., 28: 2450-2471. https://doi.org/10.1016/j.csr.2008.06.008
  13. Liu, W.C., Chen, W.B. and Kuo, J.T., 2008. Modeling residence time response to freshwater discharge in a mesotidal estuary, Taiwan. J Mar Syst, 74(1-2): 295-314. https://doi.org/10.1016/j.jmarsys.2008.01.001
  14. MacCready, P., Banas, N.S., Hickey, B.M., Dever, E.P. and Liu, Y. 2009, A model study of tide- and wind-induced mixing in the Columbia River Estuary and plume. Cont. Shelf Res. 29(1): 278-291. https://doi.org/10.1016/j.csr.2008.03.015
  15. Madsen, O.S., 1976. A realistic model of the wind-induced Ekman boundary layer, J. of phys. oceangr., 7: 248-255.
  16. Peters, H., 1997. Observations of stratied turbulent mixing in an estuary: neap-to-spring variations during high river flow. Estuar. Coast. Shelf Sci., 45: 69-88.
  17. Ro, YJ. and Choi, Y.H., 2004. Application of realtime monitoring of oceanic conditions in the coastal water for environmental management. J. Korean Soc. Oceanogr. 39(2): 48-152.
  18. Ro, Y.J., 2005. Numerical modeling of the impact of the river runoff in the formation of the anoxia in the Kangjin Bay, South Sea, Korea. In: American Geophysical Union, Spring Meeting 2005, abstract # OS22A-01.
  19. Ro, YJ. and Yoo, I.J., Variability of meteorological conditions in the Kangjin Bay, South Sea, Korea, during 2004-2005. Procc. of Korean Soc. Oceanogr, pp 176.
  20. Ro, YJ., 2007. Tidal and sub-tidal current characteristics in the Kangjin Bay, South Sea, Korea. Ocean Sci. J. 42(1): 19-30. https://doi.org/10.1007/BF03020907
  21. Ro, Y.J., Jeon, W.S., Jung, K.Y. and Eom, H.M., 2007. Numerical modeling of tide and tidal current in the Kangjin Bay, South Sea, Korea. Ocean Sci. J. 42(3): 153-163. https://doi.org/10.1007/BF03020919
  22. Ro, YJ. and Jung, K.Y., 2010. Impact of the Dam water discharge on the circulation system in the Kangjin Bay, South Sea, Korea. Ocean Sci J. 45(1): 17-35.
  23. Robert, B.G and Malcolm, L.S., 1987. Numerical simulations of the tidal-and wind-driven circulation in Narragansett Bay. Estuarine, Coastal and Shelf Sci., 24(5): 611-636. https://doi.org/10.1016/0272-7714(87)90102-8
  24. Ruggles, K.W., 1970. The vertical mean wind profile over the ocean for light to moderate winds. J. of Applied Meteorology, 9: 389-395. https://doi.org/10.1175/1520-0450(1970)009<0389:TVMWPO>2.0.CO;2
  25. Sankaranryanan, S., 2007. Modeling the tide and wind-induced circulation in Buzzards Bay. Estuarine, Coastal and Shelf Sci., 73(3-4): 467-480. https://doi.org/10.1016/j.ecss.2006.12.022
  26. Shin, E.J., Lee, S.H. and Choi, H.Y., 2002. Numerical model study for structure and distribution of the Keum River plume. J. Korean Soc Oceanogr. 7(3): 157-170.
  27. Suzuki, T. and Matsuyama, M., 2000. Numerical experiments on stratified wind-induced circulation in Tokyo Bay, Japan. Estuarine, Coastal and Shelf Sci., 50(1): 17-25. https://doi.org/10.1006/ecss.1999.0527
  28. WAMIS, 2004. Dam water discharge data. http://203.237.1.24/WKDl MNDTDATA,ASPX?code=20 18110 Accessed1Sep2004.
  29. Yanagi, T., 1983. Generation mechanism of the tidal residual circulation. J. Oceanogr. Soc. Japan, 39(4): 156-166. https://doi.org/10.1007/BF02070259
  30. Yasuda, H., 1980. Generating mechanism of the tidal residual current due to the coastal boundary layer. J. Oceanogr. Soc. Japan, 35: 241-252. https://doi.org/10.1007/BF02108929
  31. Zhai, L., Sheng, J. and Greatbatch, R.J., 2008, Baroclinic dynamics of wind-driven circulation in a stratified bay: A numerical study using models of varying complexity. Cont. Shelf Res., 28: 2357-2370. https://doi.org/10.1016/j.csr.2008.05.005