Abstract
Based on the MASNUM wave-tide-circulation coupled numerical model, seasonal variability of thermocline in the Yellow Sea was simulated and compared with in-situ observations. Both simulated mixed layer depth (MLD) and thermocline intensity have similar spatial patterns to the observations. The simulated maximum MLD are 8 m and 22 m, while the corresponding observed values are 13 m and 27 m in July and October, respectively. The simulated thermocline intensity are 1.2°C/m and 0.5°C/m in July and October, respectively, which are 0.6°C/m less than those of the observations. It may be the main reason why the simulated thermocline is weaker than the observations that the model vertical resolution is less precise than that of the CTD data which is 1 m. Contours of both simulated and observed thermocline intensity present a circle in general. The wave-induced mixing plays a key role in the formation of the upper mixed layer in spring and summer. Tidal mixing enhances the thermocline intensity. Buoyancy-driven mixing destroys the thermocline in autumn and keeps the vertical temperature uniform in winter.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Blumberg, A. F. and G. L. Mellor, 1987. A description of a three-dimensional coastal ocean model.In: N. S. Heaps, ed, Three dimensional coastal ocean models. American Geophysical Union, Washington D. C., p. 1–16.
Craig, P. D. and M. L. Banner, 1994. Modeling wave-enhanced turbulence in the ocean surface layer.J. Phys. Oceanogr. 24: 2546–2559.
Ezer, T., 2000. On the seasonal mixed layer simulated by a basin-scale ocean model and the Mellor-Yamada turbulence scheme.J. Geophys. Res. 105 (C7): 16843–16855.
Fang, G. and T. Ichiye, 1983. On the vertical structure of tidal currents in a homogeneous sea.Geophys. J. R. Astr. Soc. 73: 65–82.
Harney, R., 1971. Surface thermal boundary condition for ocean circulation models.J. Phys. Oceanogr. 1: 241–248.
Hu, D., M. Cui, Y. Li and T. Qu, 1991. On the Yellow Sea cold water mass related circulation.Yellow Sea Researc. 4: 79–88.
Kantha, L. H. and C. A. Clayson, 1994. An improved mixed layer model for geophysical applications.J. Geophys. Res. 99: 25235–25266.
Lee, S. H. and R. C. Beardsley, 1999. Influence of stratification on residual tidal currents in the Yellow Sea.J. Geophys. Res. 104(C7), 15679–15701.
Levitus, S., 1982. Climatological atlas of the world ocean. NOAA Prof. Paper No. 13. U. S. Govt. Printing Office, 173 pp. plus 17 microfiche.
Ma, J. and F. Qiao, 2004. Simulation and analysis on the seasonal variability of salinity in the Yellow Sea.Chinese J. Oceanol. Limnol. 22(3): 306–313.
Martin, P. J., 1985. Simulation of the mixed layer at OWS November and Papa with several models.J. Geophys. Res. 90: 581–597.
Mellor, G. L., 2001. One-dimensional, ocean surface layer modeling. a problem and a solution.J. Phys. Oceanogr. 31: 790–809.
Mellor, G., 2003. The three-dimensional current and wave equations.J. Phys. Oceanogr. 33: 1978–1989.
Mellor, G. L. and T. Yamada, 1982. Development of a turbulence closure model for geophysical fluid problems.Rev. Geophys. and Space Phys. 20: 851–875.
Qi, J. and Y. Su, 1998. Numerical simulation of the tide-induced continental front in the Yellow Sea.Oceanol. et Limnol. 29(3): 247–254. (in Chinese with English abstract)
Qiao, F., S. Chen, C. Li, W. Zhao and Z. Pan, 1999. The study of wind, wave, current extreme parameters and climatic characters of the South China Sea.Journal of Marine Technology Society 33 (1): 61–68.
Qiao, F., Y. Yuan, Y. Yang, Q. Zheng, C. Xia and J. Ma, 2004a. Wave-induced mixing in the upper ocean: Distribution and application to a global ocean circulation model.Geophys. Res. Lett. 31: L11303, doi: 10.1029/2004GL019824.
Qiao F., J. Ma, Y. Yang and Y. Yuan, 2004b. Simulation of the temperature and salinity along 36°N in the Yellow Sea with a wave-current coupled model.Journal of the Korean Society of Oceanography. 39(1): 35–45.
Qiao, F., Y. Yuan, T. Ezer, C. Xia, Y. Yang and J. Ma, 2004c. A three-dimensional, surface wave-ocean circulation coupled model: System description and initial testing.J. Phys. Oceanogr. (Submitted)
Xia, C., F. Qiao and Y. Yuan, 2004. Numerical simulation of the general circulation. Submitted toChinese Journal of Computational Physics. (in Chinese)
Yu, W., F. Qiao, Y. Yuan and Z. Pan, 1997. Numerical modeling of wind and waves for Typhoon Betty (8710).Acta Ocenol. Sin. 16 (4): 459–473.
Yuan, Y., Z. Pan, F. Hua, L. Sun, 1991. LAGDF-WAM numerical wave model.Acta Ocenol. Sin. 10: 483–488.
Yuan Y. 1979. The circulation of the Yellow Sea Cold Water Mass.Oceanol. et Limnol. Sin. 10: 187–196.
Yuan, Y., F. Qiao, F. Hua and Z. Wan, 1999. The development of a coastal circulation numerical model: 1. Wave-induced mixing and wave-current interaction.J. Hydrodynamics, Ser. A.14(4B): 1–8. (in Chinese)
Yuan, Y. and H. Li, 1993. Research on the circulation structure and forming mechanism of the Yellow Sea cold water mass.Science in China 23 (1): 93–103. (in Chinese)
Author information
Authors and Affiliations
Additional information
Supported by the National Basic Research Program of China (G1999043809) and the National Science Foundation of China (No. 49736190).
Rights and permissions
About this article
Cite this article
Fangli, Q., Changshui, X., Jianwei, S. et al. Seasonal variability of thermocline in the Yellow Sea. Chin. J. Ocean. Limnol. 22, 299–305 (2004). https://doi.org/10.1007/BF02842563
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02842563