碩士 / 國立交通大學 / 土木工程系所 / 105 / Averaged three or four typhoons usually pass through or by Taiwan during summer and autumn. Strong winds and atmospheric pressure changes of typhoons cause abnormal variations of sea levels and the seawater temperature. The traditional harmonic analysis can only extract astronomical tides but cannot separate atmospheric tides and thermal tides from tidal data. Considering the variations of atmospheric pressure and seawater temperature the modified harmonic analysis method is proposed to improve the function of accurately computing storm surges and thermal tides. Data of tidal, atmospheric pressure and seawater temperature at four stations, which are Taichung, Kaohsiung, Hualien and Punghu, from 2005 to 2007, were collected to examine the validity of three models, that are HA, the traditional harmonic analysis, HAP considering atmospheric pressure only, and HAPT considering both atmospheric pressure and seawater temperature.
The correlation coefficients between residual tides and threshold pressure differences or temperature differences are higher than those between residual tides and pressure differences or temperature differences by 0.157 and 0.087. Residual tides, defined the difference between measured tides and extracted tides, obtained by HA are higher than HAP and HAPT. Ratios of the potential of extracted astronomical, atmospheric and thermal tides are about 95%, 1-2% and 1%, respectively. The storm surges during the periods of typhoons by HAP and HAPT are close. Both are smoother than that by HA. The peak of each storm surge by HAP and HAPT is more obvious than that by HA.
| Identifer | oai:union.ndltd.org:TW/105NCTU5015036 |
| Date | January 2017 |
| Creators | Chiu, Min-Jie, 邱民杰 |
| Contributors | Chang, Hsien-Kuo, 張憲國 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 122 |
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