The water circulation of the South China Sea in a zone of the Vietnamese Сurrent under the influence of southern tropical cyclone in spring of 1999: results of numerical modeling

The integrated water circulation of the South China Sea in the area of coastal Vietnamese Current during transitional spring period (May 1999) has been calculated on the basis of numerical modeling. The South China Sea considerably influences the climate regime in South-East Asia, including the Far East of Russia. Here the tropical cyclones of the destructive power coming from the western Pacific or incipient in the South China Sea are developed. This specified year was selected in connection with this period of large-scale international expedition Fisheries Association of South-East Asia and Japan, the data of which are presented by Vietnamese colleagues. Spring season is used as an example of the transition from winter to summer because it’s poorly investigated. Synoptic processes in the region significantly influence the seasonal the nature of Vietnamese Сurrent. This current is directed from north to south in winter under the influence of the northeast monsoon, thus forming the cyclonic water circulation. This current is directed in the opposite direction in the summer under the influence of the southwest monsoon, forming an anticyclonic circulation. The calculations were performed for the synoptic situation, which is characterized by the presence of tropical cyclone in the southern part of the South China Sea. Results of modeling have showed that two anticyclonic and separating its cyclonic gyres exist in the specified period in the studied area. As a result, two zones of different water modifications within the Vietnamese Current are formed: water masses are transported from south to north in the northern and southern parts of the region (summer regime), and in the central part — from north to south (winter regime). On this basis, it was concluded about a transitional character of the chosen time interval when influence has not yet left winter and already coming summer monsoons affects.

1. Zhao X., Pang H., Li X., Song P. Abnormal incident analysis of tropical cyclones influencing South China Sea in 1997. J. Tropic. Oceanogr. 2008, 27, 1, 11—15.

2. Dang K. M. Oceanographic conditions of the South China Sea. Sea collection. 1974, 4, 91—93 (in Russian).

3. Barabashkina A. P., Leskov E. A. Research typhoons entering the Sea of Japan and Primorsky Krai. Proceedings FERHRI. 1968, 3, 3—33 (in Russian).

4. Mamedov E. S., Pavlov N. I. Typhoons. Leningrad, Gidrometeoizdat, 1974. 137 p. (in Russian).

5. Khromov S. P., Mammoth L. I. Meteorological dictionary. Leningrad, Gidrometeoizdat, 1974. 508 p. (in Russian).

6. Chevey P., Carton P. Les courants de la mer de Chine meridionale et leurs rapports avec le climat de l'Indochine. Note Inst. Ocean. Indochine. 1935, 26, 13.

7. Wyrtki K. Scientific results of marine investigation of the South China Sea and Gulf of Thailand. NAGA Report. 1961, 195 p.

8. Qinyu Liu, Arata Kaneko and Su Jilan. Recent progress in studies of the South China Sea circulation. J. Oceanogr. 2008, 64, 753—762.

9. Vlasova G. A., Bui Hong Long, Taranov S. N., Nguyen Xuan Ba, Belyaev V. A., Yurasov G. I., Le Dinh Mau. Background data on the South China Sea. Vladivostok, 2010. Preprint in POI. 29.04.2010. № 98. 57 p.

10. Uda M., Nakao T. Water masses and currents in the South China Sea and their seasonal change. Proc. of The Kuroshio III. Proc. of the third CSK Symposium. Thailand, Bangkok. 1973, 161—188.

11. Nguyen Z. T. Water circulation of the South China Sea in the winter and summer seasons. PhD: 25.00.28. Vladivostok, 1990. 177 p. (in Russian).

12. Xie S., Xie Q., Wang D., Liu W. T. Summer upwelling in the South China Sea and its role in regional climite variations. J. Geophys. Res. 2003, 108, 3261.

13. Zhou Hui, Yuan Dong liang, Li Ruixiang, He Lei. The western South China Sea currents from measurements by Argo profiling during October to December 2007. Chinese Journal of Oceanology and Limnology. 2010, 28, 2, 398—406.

14. Yuan Y., Liao G., Xu X. Three dimensional diagnostic modeling study of the South China sea circulation before onset of summer monsoon in 1998. J. Oceanogr. 2007, 63, 1, 77—100.

15. Polyakova A. M., Vlasova G. A., Vasilyev A. S. Influence of the atmosphere on the underlying surface and hydrodynamic processes of the Bering Sea. Vladivostok, Dal'nauka, 2002. 203 p. (in Russian).

16. Vlasova G. A., Vasilyev A. S., Shevchenko G. V. Spatial and temporal variability of the structure and dynamics of the waters of the Okhotsk Sea. Moskva, Science, 2008. 359 p. (in Russian).

17. Fel'zenbaum A. I. Theoretical basis and methods of calculation of steady sea currents. Moskva, Publishing House of the USSR Academy of Sciences, 1960. 235 p.

18. Fel'zenbaum A. I. Dynamics of sea currents. Hydrodynamics. The resume of science. Ser. Mechanics. Moskva, VINITI, 1970, 97—338 (in Russian).

19. Shapiro N. D. Formation of quasi-isopycnic circulation models of the Black Sea, taking into account the stochastic wind stress. Marine Hydrophysical J. 1998, 6, 26—40 (in Russian).

20. Vasiliev A. S. Prognostic eddy-resolving model of the basic physical fields of the ocean. The theory of dynamic processes. Sevastopol, 1983, 57—67 (in Russian).

21. Marchuk G. I. The numerical solution of problems of atmospheric and ocean dynamics on the basis of method of splitting. Leningrad, Gidrometizdat, 1974. 303 p.

22. Samarskiy A. A. Introduction to the theory of difference schemes. Moskva, Science, 1971. 552 p. (in Russian).

23. Vasiliev A. S., Vlasova G. A. Investigation of hydrodynamic structures in the South Kuril area of Western Pacific. Studies of the oceans and seas. Proceedings of the State Oceanographic Institute. 2000, 207, 55—69 (in Russian).

24. Vlasova Galina. Interaction of water and atmospheric circulation in Far Eastern Seas. CD-ROM Proceeding 1-st International Conference on Experiments/Process/System Modelling/Simulation/Optimization. N 206, Athens, Greece, 6—9 July, 2005, 7 p.

25. Vlasova G. A. Seasonal variability of the circulation of the Bering Sea. Oceanographic research. Moscow, Nauka, 2007, 266—279 (in Russian).

26. Vlasova G. A. Research of the hydrodynamic processes of NW Pacific on the basis of modeling. Ky niem 85 nam than lap vien hai duong hoc, ky yeu hoi nghi khoa hoc quoc gia. Publishing house for Science and Techonology, Hanoi, Vietnam, 2008, 701—708.

27. Vlasova G. A., Glebova S. Y. Seasonal variability of surface currents Sea of Okhotsk under the influence of synoptic processes. Bulletin of TINRO. 2008, 154, 259—269 (in Russian).

28. Vlasova G. A. Estimation of the hydrodynamic regime of the water movement under the influence of the atmospheric processes in the Bering Sea and the Sea of Okhotsk. J. of Environmental Science and Engineering. 2011, 5, 10, 1276—1281.

29. Polyakova A. M. Typing atmospheric processes over the South China Sea. Meteorology and Hydrology. 2010, 5, 17—24 (in Russian).

30. Vlasova G. A., Nguyen Ba Xuan, Bui Hong Long. Influence of synoptic processes in the dynamics of the Vietnamese current (South China Sea) in spring 1999. Meteorology and Hydrology. 2013, 4, 36—46 (in Russian).

31. Atlas of Oceanography of the South China Sea URL: http://pacificinfo.ru/data/cdrom/9/text.html (date of access: 14.05.2015) (in Russian).

32. DanLing Tang, Hiroshi Kawamura, Tran Van Dien, MingAn Lee. Offshore phytoplankton biomass increase and its oceanographic causes in the South China Sea. Marine ecology progress series. 2004, 268, 31—41.

33. Chao S. Y., Shaw P. T., Wang J. Deep water ventilation in the South China Sea. Deep Sea Res. 1996, 1, 43, 445—466.

34. Wang Qingye, Cui Hong, Zhang Shuwen. Water transports through the four main straits around the South China Sea. J. of Oceanogr. And Limnol. 2009, 27, 2, 229—236.