博士 / 國立成功大學 / 水利及海洋工程學系碩博士班 / 98 / The open lateral boundaries and surface boundary fields are the necessary forcing input to the numerical ocean model. A numerical model system has been integrated to simulate the tidally and meteorologically driven hydrodynamics in a very conveniently way to configure for any region of the earth. The hydrodynamics are driven by global astronomical tidal model at the open lateral boundaries. At the surface boundary, if wind and air pressure fields are prescribed, the data downscaling process is necessary to generate the same grid size and time step as ocean model. Typhoons, strong wind and low air pressure, is the major factor to cause the coastal hazardous. However, the traditional linear interpolate scheme of meteorological data downscaling will destroy the structure of typhoon. After applying the traditional linear interpolation to the data downscaling, the typhoon should go as disappear/appear. In order to avoid this situation, a storm pathway downscaling scheme is proposed to interpolate meteorological fields to fit the computational grid system.
In order to validate the present model system, a series of numerical experiments were adopted to demonstrate the effect of the model results by downscaling method, two or three dimensional simulations and the interaction of tide and storm surge. The experimental results show the maximum tidal level difference over Taiwan Strait between two dimensional runs and three dimensional runs can be about 50 cm. The interaction of tide and storm surge is about 12 % of maximum storm surge deviations. Final, the storm event in North Sea and typhoon event over Taiwan water are used to exam the presented downscaling method. The results show that the presented downscaling method could downscale the meteorological fields in keeping with physical sense.
The validated model system is used to simulate the tidal propagation in Taiwan Strait. The references indicate that the amplitude of semidiurnal tide M2 has maximum values in the middle of Taiwan Strait is due to consist of incident and reflected M2 tides. In present study, the characteristics of co-phase distribution of M2 tide in Taiwan Strait is used to discuss consists of M2 tide. We found that, there must exist a third M2 source tide propagated from south of Taiwan Strait into Taiwan Strait then the co-phase of consist of incident, reflected and northward propagated M2 tides will satisfy the measurements along Taiwan Coast. Furthermore, the shallow water constituents’ results are used to discuss the tidal propagation in the Taiwan Strait. Due to the shallow water constituents are generated inside the Taiwan Strait, the constituent M4 is only consist of incident and reflected Kelvin waves. Without the third source of M4 constituent, the co-phase of M4 over Taiwan Strait shows two amphidromic points clearly.
The model system is also used to simulate the storm surges over Taiwan water. Nine typhoon cases corresponding to nine tracks have been selected to simulate the storm surge deviations around the coastal of Taiwan. The maximum storm surge deviations around the coastal of Taiwan during each typhoon case are then represents.
| Identifer | oai:union.ndltd.org:TW/098NCKU5083004 |
| Date | January 2010 |
| Creators | Ming-DaChiou, 邱銘達 |
| Contributors | Chia Chuen Kao, 高家俊 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 135 |
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