하계 동중국해 북부 해역에서의 해수 혼합 = Mixing of Sea Waters in the Northern Part of the East China Sea in Summer

국문 초록 (Abstract)

하계 동중국해 북부 대륙붕 해역에서 해수 혼합을 연구하기 위하여 2005년 8월과 2006년 8월에 한국해양연구원 연구선 이어도호를 이용하여 해수 물성 및 난류 관측을 수행하였다. 유속 변형으로부터 산출한 난류운동에너지 소산율은 표층에서 $10^{-7}{\sim}10^{-4}$, 저층에서 $10^{-7}{\sim}10^{-6}$와 수온약층에서 $10^{-7}$ W/kg의 높은 값이 나타났다. 관측 자료는 표층의 경우 바람에 의해 지속적으로 혼합이 이루어짐을 보여주었다. 수온약층 하부에서의 높은 소산율은 내부파의 영향으로 판단된다. 저층의 높은 소산율은 저층의 탁도 분포의 경향과 일치하여 조류에 의한 해저면층 교란의 결과임을 시사해주었다. 바닥에서의 연직확산계수는 낮은 안정도와 높은 난류상태의 복합적인 영향으로 $10^{-3}{\sim}10^{-2}m^2/s$로 높은 값이 나타났다.

다국어 초록 (Multilingual Abstract)

In order to investigate the mixing of sea waters on the continental shelf in the northern East China Sea, Korea Ocean Research and Development Institute conducted hydrographic surveys including turbulence measurements using the R/V Eardo in August 2005 and August 2006. The turbulent kinetic energy dissipation rates based on velocity shear measurements are estimated to be $10^{-7}{\sim}10^{4}$, $10^{-7}{\sim}10^{-6}$, and $10^{-7}$ W/kg in the surface layer, bottom layer, and lower thermocline, respectively. The data sets suggest that surface layer water is being constantly mixed by winds. High dissipation rate in the lower thermocline seems to be caused by internal waves. The bottom layer with high dissipation rate also shows high turbidity, indicating the effect of tidal stirring turbulence. The vertical eddy diffusivities are $10^{-3}{\sim}10^{-2}m^2/s$ near the bottom, and these high values appear to arise from both the low stability and high turbulent mixing.

참고문헌 (Reference)

1 "동중국해 중·서부해역의 해양순환 연구" 428-, 2000

2 "Vertical Mixing in the bottom mixed layer near the continental shelf break in the East China Sea" ocea (ocea): 437-448, 1994

3 "Structure and eastward extension of the Changjiang River plume in the East China Sea" 108 (108): 3077-, 2003

4 "Microstructure measurements in the Atlantic Equatorial Undercurrent during GATE" 285-308, 1979

5 "Measurements of the turbulent energy dissipation rate e and an evaluation of the dispersion process of the Changjiang Diluted Water in the East China Sea" 111 (111): 2006

6 "Evolution of suspended sediment patterns in the East China and Yellow Seas" 39 : 26-34, 2004

7 "Estimates of the local rate of vertical diffusion from dissipation measurements" ocea (ocea): 83-89, 1980

8 "Episodes of nonlinear internal waves in the northern East China Sea" 33 (33): 2006

9 "Discharge of the Changjiang" 57-76, 1985

10 "Change of the discharge and sediment flux to estuary in Changjiang River" 129-148, 1998

11 "An experiment on turbulence in a density-stratified fluid" Monash University 1974

12 "A new free-fall profiler for measuring biophysical microstructure" 19 : 780-793, 2002