碩士 / 國立臺灣海洋大學 / 海洋環境資訊學系 / 98 / Abstract
Sea condition may change from calm to rough in a short time. These rapidly growth waves create dangerous condition for mariners, especially in the busy sea lanes, such as the sea near the Taipei Harbor. This study analyze wave and wind information recorded off the Taipei Harbor between 2001 and 2007 from the Center for Harbor Technology. In this study, we defined the rapid growth waves as those grow two times in height and reach 1.5m in a six-hour period. In the near seven year period, there were 374 rapid growth wave events. We analyze the significant wave height, significant wave period, wind speed, wind direction and atmospheric pressure in these rapid growth events.
It is found that these events mostly occur in the winter between December and February with a probability of 42%. The significant wave period decrease at first before the growth of the wave height. Then the wave period increases with the increase of wave height. The wind speed also increase during the rapid growth event, about 60% of the events larger than the all around mean speed of 6.5m/s. As to the wind direction, although wind blows from various directions before the rapid growth event, the wind direction became from the north to the northeast after the event.
There were 4 events with the wave height increased up to 10 times in the six-hour period. These events were all due to the winter front passage accompanied with the strong northeasterly wind due to the continental atmospheric high pressure. We also compared the events occurred in the Taipei Harbor and the rapid growth events occurred in off the Badou fish Harbor, Londong coast and Kueisan Island. These are locations on the north coast with wave information available. We found that the Taipei Harbor area has the highest ratio of wave height increase after and before the event, followed by Longdong, Kueisan island and Badou fish Harbor. About 40% of the time, Taipei Harbor and Longdong have the rapid growth wave event simultaneously. Although the mean wave growth ratio for the Taipei Harbor, a four, is larger than that of the Longdong coast, which is 2.7; the wave height after the rapid growth is higher at Longdong coast than that in the Taipei Harbor area. This is due to the smaller wave height in the Taipei Harbor area before the growth event. It can be said the rapid growth wave condition in the Taipei Harbor area is not as dangerous as that in the Longdong coast.
| Identifer | oai:union.ndltd.org:TW/098NTOU5282008 |
| Date | January 2010 |
| Creators | Lin-Lin Huang, 黃玲玲 |
| Contributors | Cheng-Han Tsai, 蔡政翰 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 69 |
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