碩士 / 國立成功大學 / 水利及海洋工程學系碩博士班 / 101 / The Central Weather Bureau of Taiwan has deployed an ocean data buoy at the 400 km offshore of eastern Taiwan where the water depth is 5600m. This open area is suitable for the existence of fully developed waves, which further helps explore the wind wave characteristic in the presence of swells. A stable wind prevailed during the period of 26th of September to 30th of September, 2010, following the wind data acquired from the data buoy. The wave data during this period were sorted according to the significant wave hight, average wave period and wave age into three parts, i.e. first wave age with strong swells, the second wave age with wind wave and swell matures and the third wave age with fully-developed waves. Following WMO’s guideline of wave analysis and forecasting analysis in 1998, we analyzed the swells out of Typhoon Malakas. A weak swell in third wave age is identified, and later on wind wave is becoming most-obvious. Finally, the peak frequency of wind-wave spectra shifts gradually from 0.2Hz to 0.16Hz. At 22 o’clock on 30th of September, the wave spectral properties derived from data buoy matched well with the peak frequency and energy distribution of corresponding P-M spectrum, indicating that the waves are approaching fully-developed sea. In addition, a swells out of Typhoon Ma-on prevailed during the period of 16th of July to 18th of July, 2011, following the data acquired from the data buoy. The peak frequency of swell is 0.07Hz. Swell is generally of a much lower frequency than a young wind sea, so in this case the two wave systems are well separated, both in frequency. a low-frequency spectrum oriented in typhoon representing the swell and a much broader spectrum at higher frequencies oriented towards westerly directions, representing the locally generated wind sea. The one-dimensional spectrum obtained by integrating this two-dimensional spectrum over the directions is equally distinctive because the swell and the local wind sea are well separated in frequency. When the swell was away from the buoy, the one-dimensional spectrum change to the one peak spectrum which only remain local wind energy. Compared the results of previous study with the modified Wallops spectral, we find that m value of modify Wallops spectral, which is of about 3 to 4 is well applicable to the in eastern ocean of Taiwan.
| Identifer | oai:union.ndltd.org:TW/101NCKU5083101 |
| Date | January 2013 |
| Creators | Jia-weiHuang, 黃嘉緯 |
| Contributors | Ching-Jer Huang, 黃清哲 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 53 |
Page generated in 0.0011 seconds