台湾海峡表层水温的长期变动及其生态响应研究

Climate change and its ecological consequences attract great attention in the entire society. However, how the climate regulates the ecosystem is not well understood. Increasing awareness among the oceanographers and the climate scientists has rapidly pushed forward the progress on this subject. Comparing physical and biological variations in the ocean is one basic way to explore the climate-ocean variability and its ecological response. .This study aims at disentangling the basic pattern of Sea Surface Temperature(SST) long-term low-frequency variability and its effect on the ecosystem in the Taiwan Strait region, which is a typical subtropical sea with monsoon driving located between the East China Sea and South China Sea. The design of the study is to identify warm and cool events and the corresponding fluctuation of phytoplankton biomass by doing comparison between SST and Chla time-series, and to see if there are any other abnormal chemical and biotic signals during warm events and cool events by searching the in situ dataset. NOAA AVHRR Sea Surface Temperature(SST) data from 1985 to 2001 and SeaWiFS Chla data from 1997 to 2002 as well as in situ physical, chemical and biological data collected from 1981 to 1999 are therefore used in this study. Spatial and temporal EOF decomposition is one method mainly applied. .Significant results include:.1) The pattern of SST inter-annual variability.During the period from 1985-2001, the warmest year is 1998, while the coolest is 1985. The frequency of warm and cool fluctuation had increased since 1990. The first EOF temporal mode(37.4%) shows the pattern of inter-annual variability, but its low eigenvector suggests that inter-annual variability is not dominant. Inter-decadal variability would probably be an important feature. The comparison of SSTA time-series with SOI implied that warm events occurred in the Taiwan Strait with 1-2 years lag to tropical El Nino events. .2) Temporal and spatial features of coastal upwelling and the coupling of SST and Chla fluctuations during southeast monsoon.Two upwelling centers located in the southern and northern Taiwan Strait showed different strength, with the former weaker than the latter. During the period from 1985-2001, this feature appeared the most striking in 1987 but the weakest in 1994. Underlying mechanisms remain unknown yet. Chla spatial structure shows tight coupling with the upwelling spatial structure only in 1998, hinting that here in this region upwelling might not a predominant factor regulating the phytoplankton standing stock..These are the first observation of long-term ocean-ecosystem variability in the Taiwan Strait, especially in the aspect of upwelling system. .Finally a database was constructed including all the remote sensing, in situ and statistical fishery dataset, and was further developed into an information system utilizing ArcGIS platform..

利用现场及水色水温遥感数据，分析1988—1997年台湾海峡表层水温及叶绿素年际变动，研究海域上升流范围、强度的变化，探索其与ElNino/LaNiNa之间的远关联，从而认识当地和冻痰奈锢砉潭陨档挠跋欤ρＪ降南低彻怪蛳禄。⑽Ｓ蛴嬉倒芾硖峁┛蒲б谰荨