Characteristics of Seasonal Wind and Wind-driven Current in the Gulf of Thailand
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Abstract
The Gulf of Thailand is bounded by Latitude 6° to 14°N and Longitude 99° to 105°E. It is located on the continental shelf connecting to South China Sea via the southern entrance. The Gulf is border by Thailand, Cambodia and Vietnam on the eastern, northern and western side respectively. The Gulf receives high solar radiation throughout the year. The NE and SW monsoon controls the local weather around the Gulf. The monsoonal wind plays an important role in controlling the wind pattern, rainfall over Thailand, and also controlling water circulation in the Gulf of Thailand. The project objective is to simulate wind regime over the Gulf and wind-driven circulation in the Gulf of Thailand during the year 2000-2002. The study time span cover La Niña, normal and El Niño period respectively. The study is accomplished through to use of WRF model and 2-D water circulation model. Wind regime from WRF model was the input to the water circulation model. Statistical analysis was performed on the wind data in order to study the effect of El Niño and La Niña events on the wind pattern over the Gulf of Thailand. Wind pattern from the WRF model was comparable to the satellite (observed) wind. Winddriven circulation was similar to the results of earlier studies. During rainy season, the westerly and southwesterly wind from the Indian Ocean caused the wind-driven current in the Gulf and the upper Gulf to flow in a clockwise direction. Small eddies existed some locations in the Gulf. During winter, high pressure system from Siberia caused wind in South China Sea to flow from the east to Gulf entrance. While inside the Gulf, the wind deflected to NE wind and caused the wind-driven circulation in the Gulf and the upper Gulf to flow in a counterclockwise direction. During summer, wind from South China Sea blew from the east direction. While inside the Gulf, the wind deflected to SE wind. And the SE wind deflected to S wind when entering the upper Gulf of Thailand. The pattern of wind-driven current in the Gulf was similar to that in during the winter. When easterly wind was strong near the lower eastern coast of the Gulf, there would be a northward flow of water along the coast. The effect of the El Niño event increased wind speed over the Gulf and deflect the wind direction by 10°. On the other hand, the effect of the La Niña event reduced wind speed over the Gulf and deflects the wind direction by the same degree. The wind-driven circulation pattern did not change with the El Niño / La Niña event.
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Copyright © 2008 Department of Geology, Faculty of Science, Chulalongkorn University. Parts of an article can be photocopied or reproduced without prior written permission from the author(s), but due acknowledgments should be stated or cited accordingly.
References
Amnuaylojaroen, T., and Kreasuwun, J., 2012. Investigation of fine and coarse particulate matter from burning area in Chiang Mai, Thailand using the WRF/CALPUFF. Chiang Mai Journal.39, 2: 311-326.
Aschariyaphotha, N., Wongwises, P., Wongwises, S., Humphries, U.W.,and Xiaobao, Y., 2008. Simulation of seasonal circulations and thermohaline variabilities in the Gulf of Thailand. Advances in atmospheric sciences, 25, 3: 489-506.
Blumberg, A.F., 1977.Numerical tidal model of Chesapeake Bay. Journal of the Hydraulics Division, Proceedings of the American Society of Civil Engineers, 103(HY1):1-10.
Booncherm, C., Vongpintu, V.,and Nutpramoon, R., 2001.The characteristic of the sea surface residual flow and the circulation in the Gulf of Thailand from the long term collected data of the SEAWATCH Thailand program. Proceedings of the 39th Kasetsart University Annual Conference: Science, Natural Resources and Environmental Economics, Bangkok (Thailand), 39: 315-325.
Buranapratheprat, A., and Bunpapong, M., 1998.A two dimensional hydrodynamic model for The Gulf of Thailand. Proceedings of the IOC/WESTPAC Fourth International Scientific Symposium, 469-478.
Buranapratheprat, A., Yanagi, T., Sojisuporn, A., and Booncherm, C., 2006.Influence of local wind field on seasonal circulations in the upper Gulf of Thailand. Coastal Marine Science, 30, 1: 19 - 26.
Carvalho, D., Rocha, A., Gomez-Gesteira, A., and Santos, C., 2012.A sensitivity study of the WRF model in wind simulation for an area of high wind energy. Environmental Modeling & Software, 33: 23-24.
Chotamonsak, C., Salathe, E.P., Kreasuwan, A., and Chantara, S., 2012.Evaluation of Precipitation simulations over Thailand using a WRF regional Climate model. Chiang Mai Journal.39, 4: 623-638.
Emery, C. et al., 2001.Enhanced Meteorological Modeling and Performance Evaluation for Two Texas Ozone Episodes, Environ, International Corporation.
Idris, N.H., and Mohd, M.L.S., 2007.Total sea surface current circulation pattern in the South China Sea derived from satellite altimetry.Asian Conference on Remote Sensing, Kuala Lumper Malaysia, PWTC: (12-17 November 2007).
Kwun, H. J., Kim, Y.K., Seo, U.W.,and Jeong, J.H., 2009.Sensitivity experiments of winds prediction with planetary boundary layer parameterizations. Scientific and Technical Symposium on Storm Surge, COREE, 51: 63-77.
Menendez, F.J. et al., 2012. Using WRF to generate high resolution offshore wind climatolocies. Climate dynamics, 85-91.
Papanastasiou, D.K., Melas, D., and Lissaridis, I., 2010.Study of wind field under sea breeze conditions; an application of WRF model. Atmospheric Research, 98: 102-117.
Phuwieng Prakhammintara, 2000. Impacts of ENSO on rainfall, temperature and tropical cyclone frequency in coastal areas of Thailand. Master’s Thesis, Department of Marine Science, Faculty of Science, Chulalongkorn University. 132pp.
Phuwieng Prakhammintara, 2007.Correlation between heat flux, moisture and wind pattern over the Indian Ocean and southwest monsoon intensity in Thailand by using MM5 numerical model. Doctoral dissertation, Department of Marine Science, Faculty of Science, Chulalongkorn University. 140pp.
Qi, Y., Zhang, A.,and Shi, P.,2010.Extreme wind, wave and current in deep water of South China Sea. The International Society of Offshore and Polar Engineers, 20, 1: 18-23.
Singhruck, P., 2001. Circulation features in the Gulf of Thailand inferred from SeaWiFS data. The Asian Conference on Remote Sensing, 22: (5-9 November 2001), Singapore.
Snidvongs, A., and Sojisuporn, P., 1997.Numerical simulation of the net circulation in the Gulf of Thailand under different monsoon regimes. In Proceeding of the first Technical Seminar on marine fishery resources survey in the South China Sea, Area I: Gulf of Thailand and Peninsular Malaysia, Samutprakarn, Thailand: Training Department, Southeast Asia Fisheries Development Center, 1: 54-72.
Sojisuporn, P., Morimoto, A., and Yanagi, T., 2010.Seasonal variation of sea surface current in The Gulf of Thailand. Coastal Marine Science, 34, 1: 000-000, 2010.
Yanagi, T., and Takao, T., 1998.Seasonal variation of three-dimensional circulations in the Gulf of Thailand. La mer, 36: 43-55.
Yanagi T., Sachoemar I. S., Takao T., and Fujiwara S., 2001.Seasonal variation of stratification in the Gulf of Thailand. Journal of Oceanography, 57: 461-470.