The coastal current is influenced by coastline topography, its advection direction is parallel with coastline because different periodic of wind field function makes the ocean dynamics is more complicated in coastal. In order to treat the effects of topography and wind to coastal current variations, we make long time observation data about ocean and meteorology and analyze them near the harbor of HSinDa in Kaohsiung .
This research use bottom Acoustic Doppler Current Profiler
(bm-ADCP ) , Temperature and Pressure Logger(TP ) , anemometer and wind direction vane to observe flow field ,tidal and wind field in the locality. The collected data are analyzed through a variety of time series analysis technique , such as strain wave, harmonic analysis , Fast Fourior Transform (FFT) analysis that uses different frequency wave bands make an relevant analysis materials and then.
The results show that (1) when sea-land breeze was weak, the main axial angle of diurnal tide ellipticity of the current was parallel with the coastline direction. Because the friction of sea flow affected; the ellipticity became smaller and assumed the reciprocal motion¡Fwhen sea-land breeze was stronger, diurnal tide ellipticity of the current was bigger, and main axial angle from coastline parallel changes to follow the sea-land breeze heading. It means sea-land breeze can affect the surface flow motion. (2)When a front passed in winter, it produces the current faced to the southeast along the coast. In the energy spectrum effect, the wind field and the flow field have the same peak of the period, the period was 4 days, 5.5 days, and 8 days, it means that the correlation of the flow field and wind field is good; this result is closed with the observes in land station. (3)In the period of southwest monsoon, there has coastal current toward northwest in the southwest of Taiwan straits. In the other period, the direction of current always moved toward southeast. The result of the low-frequency filter, the flow is smaller than tidal current and wind-drift current. It means that this sea area is affected by tide current and wind-drift current.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0910107-221050 |
| Date | 10 September 2007 |
| Creators | Chang, Chun-hsiang |
| Contributors | Yu-huai Wang, Chung-pan Lee, Kuan-yu Chen, I-huan Lee |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0910107-221050 |
| Rights | not_available, Copyright information available at source archive |
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