A study of the circulation in the South China Sea during the summer of 2000 using a generalized terrain-following ocean model

WANG Hui-qun; YUAN Yao-chu; GUAN Wei-bing; LOU Ru-yun; WANG Kang-shan

Article Contents

Article Navigation > Haiyang Xuebao > 2003 > 25(6): 20-30

WANG Hui-qun, YUAN Yao-chu, GUAN Wei-bing, LOU Ru-yun, WANG Kang-shan. A study of the circulation in the South China Sea during the summer of 2000 using a generalized terrain-following ocean model[J]. Haiyang Xuebao, 2003, 25(6): 20-30.

Citation:

PDF( 498 KB)

A study of the circulation in the South China Sea during the summer of 2000 using a generalized terrain-following ocean model

1.
Key Laboratory of Ocean Dynamic Processes and Satellite Oceanography, Hangzhou 310012, China;Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China
2.
Key Laboratory of Ocean Dynamic Processes and Satellite Oceanography, Hangzhou 310012, China;Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China;Center for Coastal and Atmospheric Research, Hong Kong University of Science and Technology, Hong Kong, China

Received Date: 2003-03-01
Rev Recd Date: 2003-05-07

Abstract

Abstract

Based on the hydrographic data obtained by the cruise in August 2000 in the South China Sea (SCS), the revised Princeton Ocean Model (POM) with a generalized terrain-following coordinate system, i.e., the -T-F ocean model (GTFOM) was firstly adopted to study the circulation in the SCS during summer.The observational area is covered well by an orthogonal curvilinear grid in the horizontal, while in the vertical a generalized terrain following grid is set up which is similar to a z-level grid in most part of z-direction, but departs from the z level constraint near the bottom boundary, such that the lowest layer follows the bottom topography.With the actual topography and horizontally uniform, vertically varying buoyancy field, the comparison between the two numerical experiments shows that the adopted vertical grid scheme of GTFOM is better than the traditional sigma coordinate scheme, and the systematic error produced by the horizontal pressure gradient calculation near steep topography be comes much smaller when the scheme GTFOM is used.For the calculation of circulation in the SCS during the summer of 2000, there are two computed methods, i.e., the diagnostic and semidiagnostic calculations.The horizontal mixing coefficients for viscosity and diffusivity are calculated by two Smagorinsky-type for mulations.It is found by several numerical experiments that the computational results are sensitive to the taken values of their parameters.Comparisons between the diagnostic and semi diagnostic results indicate that they agree qualitatively, but there are some differences between them in quantity.In the semi diagnostic calculation, the flow field is hy drodynamically adjusted with the density field, wind stress and bottom topography, moreover, the small scale noises are removed.The main feature of circulation over the computational domain of SCS during August 2000 is as follows: There exists many warm and cold eddies, and among them the most notable eddy is the anticyclonic warm eddy southeast off Vietnam, and its center is located at 11°51'N, 112°11'E and its horizontal scale is about 300 km.East off this warm eddy there is a cyclonic cold eddy.The existence of such two cold and warm eddies is one of important circulation char acteristics in the SCS during the summer of 2000.The northeast part of SCS is dominated mainly by an anticyclonic circulation system, while it becomes cyclonic circulation system in the southeast part of SCS.Additionally, a western intensification phenomenon obviously occurs in the distribution of circulation in the SCS.
- circulation in the South China Sea,
- generalized terrain-following ocean model,
- three dimensional numerical simulation

FullText(HTML)

References(20)

References

袁耀初,赵进平,王惠群,等.南海东北部450 m以浅水层与深层海流观测结果及谱分析[J]中国科学(D辑),2002,32(2):163-176

丁一汇,李崇银南海季风爆发和演变及其与海洋的相互作用[C].北京:气象出版社.1999.

SU Ji-lan. Circulation dynamics of the China seas north of 18°N[A]. Allan R Robinson, Kenneth H Brink. The Sea:Vol.Ⅱ[M]. John Wiley & Sons Inc, 1998.483-505.

SU Ji-lan, XU Jian ping, CAI Shu-qun, et al. Circulation and eddies in the South China Sea[A]. Onset and Evolution of the South China Sea Monsoon and Its Interaction with the Ocean[C]. Beijing:China Ocean Press, 1999. 272-279.

蔡树群,苏纪兰,甘子钧,等夏季南海上层环流动力机制的数值研究[J]海洋学报,2002,24(1):1-7

MELLOR G L, HAKKINEN S, PATCHEN R, et al. A generalization of a sigma coordinate ocean model and an intercomparison of model vertical grids[A]. PINARDI N, WOODS J D. Ocean Forecasting:Conceptual Basis and Applications[M].Springer-Verlag, 2002. 55-72.

GERDES R. A primitive equation ocean circulation ocean model using a general vertical coordinate transformation. Part 1.Description and testing of the model[J]. J Geophys Res, 1993, 98:14 683-14 701.

BELL M J. Vortex stretching and bottom torque in the Bryan-Cox ocean circulation model[A]. Application T. N. 17[M].The Met. Office, London Road, Bracknell, Berkshire, RG122SY, UK, 1997.

Haney R L. On the pressure gradient force over steep topography in sigma coordinate models[J]. J Phys Oceanogr, 1991,21:610-619.

SONG Y, Haidvogel D. A semi-implicit ocean circulation model using a generalized topography-following coordinate system[J]. J Comput Physics, 1994, 115:228-244.

Mellor G L, YAMADA T. Development of a turbulence closure model for geophysical fluid problems[J]. Rev Geophys,1982, 20:851-875.

SMAGORINSKY J, MANABE S, HOLLOWAY J L. Numerical results from a nine-level general circulation model of the atmosphere[J]. Mon Weather Rev, 1965, 93:727-768.

FLATHER R A. A tidal model of the northwest European continental shelf[J]. Memoires de la Societe Royale des Sciences de Liege, 1976, 6(10):141-164.

MELLOR G L. User's guide for a three-dimentional, primitive equation, numerical ocean model[B]. Report[R]. Prog in Atmos Ocean Sci, Princeton University, Princeton NJ 08540-0710, 1998. 41.

BECKMANN A, HAIDVOGEL D B. Numerical simulation of flow around a tall isolated seamount. Part I. Problem formulation and model accuracy[J]. J Phys Oceanogr, 1993, 23:1 736-1 753.

YUAN Yao-chu, SU Ji-lan, PAN Zi-qin. Volume and heat transports of the Kuroshio in the East China Sea in 1989[J]. La Mer, 1992, 30:251-262.

SARKISYAN A S, DEMIN Yu L. Large sacle oceanographic experiments[A]. WCRP Publication Series:Vol. 2, No. 1[M]. Tokyo, 1983. 201.

WANG Hui-qun, YUAN Yao-chu. Three dimensional diagnostic, semidiagnostic and prognostic calculations of current in the East China Sea in April of 1994[J]. Acta Oceanologica Sinica, 2001,20(1):15-28.

刘勇刚,袁耀初,苏纪兰,等.1998年夏季南海环流[J].科学通报,2000,45(12):1 252-1 259.

卜献卫,袁耀初,刘勇刚.P矢量方法在南海夏季环流诊断计算中的应用[J]海洋学报,2001,23(3):8-16.

Relative Articles

Supplements(0)

Cited By

Proportional views