碩士 / 國防大學中正理工學院 / 應用物理研究所 / 95 / The data observed over the sea area southeast of Taiwan from July 29 to August 5, 2004 are used and AREPS (Advanced Refractive Effects Prediction System) of U.S. Navel is implemented to analyze the characteristics of the evaporation ducts. The WRF (Weather Research and Forcast model) model is then used to simulate the atmospheric environment of the ducts for comparison.
During the observation period, the weather was affected by the Pacific Ocean High. The vertical mixing was suppressed by descents and the low-level refractive index was then increased. The evaporation duct depths were estimated to be between 15 and 28 m. The simulaed evaporation duct depths were estimated to be between 10 and 20 m. The results of the simulations indicate that the formation and development of the ducts was mainly dependent on the evolution of the water vapor gradient and the transport of water vapor was positively related to the convergence field of the environmental flow. In addition, under the influence of topography, the variation of the impinging angle of environmental flow was the main reason for the change of the low-level water vapor gradient along the southeast coast of Taiwan.
The predictability tests of this study indicate that the WRF Model has the ability to simulate the atmospheric structure near the sea surface. The stability of simulation was well maintained. For the simulation of the elevated ducts, the best boundary layer scheme is the YSU scheme. For the simulation of the evaporation ducts in the lower boundary, the best one is the MRF scheme. For the overall performance of the boundary layer scheme, the MRF scheme has the best results. WRF Model has the ability to predict the elevated and evaporation ducts for 12 and 32 hours, respectively.
| Identifer | oai:union.ndltd.org:TW/095CCIT0504006 |
| Date | January 2007 |
| Creators | LIN YAN-CEN, 林彥岑 |
| Contributors | , 汪建良, 朱昌敏 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 105 |
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