碩士 / 國立臺灣大學 / 海洋研究所 / 96 / Long-term moored current velocity, sea temperature and sea level anomaly (SLA) measured from satellite altimetry are used to study the characteristics and causes of hydrographic (current and sea temperature) intra-seasonal variation in the northern and central South China Sea (SCS). The results indicate that the current intra-seasonal variations are generally in the form of clockwise and anti-clockwise rotating eddies alternately, and the sea temperatures have tendency to increase/decrease in the clockwise/anti-clockwise rotations. Besides, the periods of intra-seasonal variations vary with areas, from several days to a month in the northern SCS and several days to two months in the central SCS.
SLA data display that there are eddies with different scales, and these eddies have regional characteristics. In the northern SCS, limited by topography, the horizontal scales of eddies are less, and the radius of them are about 0.5-1 degree; in the central SCS, the scales are larger due to the broad ocean basin, and the radius are about 1-2 degree. The moving directions of eddies are not constant, but usually westward.
Comparing SLA with long-term current and sea temperature data, they are in high correlation. While cold/warm eddies pass the mooring stations, current directions display anti-clockwise/clockwise rotation and temperatures decrease/increase. The phenomena are more obvious in the central SCS. The affection of eddies can reach to about 500-meter depth. Also, eddies have impact on some intra-seasonal variation in the depth of thermocline. Above all indicate that the existence of mesoscale eddies are important factors of the current and sea temperature intra-seasonal variation in SCS.
| Identifer | oai:union.ndltd.org:TW/096NTU05274030 |
| Date | January 2008 |
| Creators | Yu-Ying Huang, 黃于盈 |
| Contributors | Tswen-Yuang Tang, 唐存勇 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 26 |
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