台湾海峡及其邻近海区海洋动力环境特征的研究

【作者】 胡建宇；

【导师】 洪华生；

【作者基本信息】 厦门大学 ， 环境科学， 2002， 博士

【摘要】 本论文分为两个部分。第一部分以温度、盐度作为主要的海洋动力环境要素，采用多周日定点连续观测、走航观测等先进的调查方法，取得了六个航次大量的现场调查资料，并结合多年的卫星遥感海面水温资料与适用的普林斯顿海洋模式，分析得到台湾海峡冬、夏季海洋动力环境具有以下几个主要特征：（1）冬季闽浙沿岸水除了传统所认为的偏南向流动外，还在平潭东南海域分出一个分支呈东南向指向台湾海峡中部，这与地形、岸形、季风减弱和黑潮入侵水等因素有关，由于此低温低盐水1998年2～3月向海峡中部入侵，使得锋面的位置也移到海峡中部，在锋面附近出现表层叶绿素和颗粒有机碳的高值区，因此，1998年春季台湾海峡北部渔场的位置也移到海峡中部附近；（2）黑潮入侵水在1998年2～3月对台湾海峡的影响强于其他年份，这一海洋动力环境变化与1997～1998年的ENSO事件有一定的联系；（3）夏季台湾海峡西部近岸一些与上升流有关的低温（高盐）区存在较大的变异性，具有年际变化、月际变化、日间变化和周日变化特性，其演变过程与风场等的变异有关，对ENSO事件有一定的响应，如1997年8月台湾海峡西部近岸上升流较弱，而且还引起海洋生态环境、渔场位置等的变化；（4）台湾浅滩附近海域的上升流区由于受到水系交汇、锋面移动、潮汐等因素的影响而具有短期的变化。第二部分采用6年的TOPEX／POSEIDON（T／P）卫星高度计资料分析得到整个中国近海及其邻近海区8个主要分潮（M₂，S₂，K₁，O₁，Sa，P₁，N₂和K₂）的潮汐调和常数，并绘制出相应的等潮时线和等振幅线图，进一步揭示出台湾海峡及其邻近海区一些重要的潮汐特征，认为台湾海峡8个主要分潮的潮波运动有所不同，而且这一研究也为T／P高度计资料在中国近海的应用提供了一个有效的潮汐模型，从而改善卫星测高的准确度，也可为台湾海峡潮波数值计算模型提供可靠的边界条件；还应用T／P卫星高度计和AVHRR海面水温资料，分析了南海北部海区对三个热带气旋（2000年7月的Kai-Tak台风、1994年6月的Russ热带风暴和2000年8-9月的Maria热带风暴）的响应，结果表明这些热带气旋过境之后会在南海北部产生一个气旋式涡旋，可延续2周左右，具有低温核，其核心与周围的温差大于2℃。更多还原

【Abstract】 This thesis is composed of two parts. The first part is the study of the structure and variability of temperature and salinity in the Taiwan Strait. The second part is the application of satellite altimeter data in the Taiwan Strait and its adjacent areas.Applying multi-days time series observations, underway measurements and some other advanced surveying methods, six cruises of temperature, salinity and currents in situ data have been collected in the Taiwan Strait. Integrating these in situ data with several years of sea surface temperature remote sensing data and applicable Princeton Ocean Model, the wintertime and summertime marine dynamical environment characteristics in the Taiwan Strait have been concluded. These are: (1) In winter, Minzhe Coastal Water not only flowed southwestward along the Fujian coast as usual, but also intruded to the central part of the strait from the southeastern sea area near Pingtan during February-March, 1998, which is associated with coastal line, bottom topography, monsoon weakening and Kuroshio intrusion. Therefore, the front, accompanied with high nutrient zone, moved accordingly so as to make the fishing ground move to the central part of the Taiwan Strait in the spring of 1998. (2) The Kuroshio intrusion water had a stronger influence on the Taiwan Strait during February-March of 1998, which is related to the ENSO event of 1997-1998. (3) In summer, some upwelling-related low temperature (high salinity) regions along the western coast of the Taiwan Strait have strong inter-annual, monthly, inter-diurnally and daily variability. This is greatly associated with the wind field variability and has a possible response to the ENSO event. In August of 1997, the coastal upwelling near the western coast of the Taiwan Strait was weaker and induced the variability in the marine ecological environment and fishing ground. (4) As for the upwelling region near the Taiwan Bank, it is characterized with short-term variability because it is strongly affected by water mass interaction, front movement and tides.Some important tidal features of 8 major tidal constituents (Mz, S2, KI, Oj, PI, Sa, N2 and Ka) have been obtained in the China Seas and their adjacent sea areas using sixyears of the TOPEX/POSEIDON altimeter data. Both co-tidal and co-range charts for these major tidal constituents agree well with those of the previous researches with the uses of the observational data from coastal tidal gauge stations and the numerical models. In addition, these charts further indicate some important features of the tides in the Taiwan Strait and its adjacent, indicating that these 8 tidal constituents possess with different tidal motion. This study can serve as an efficient ocean tide model for the application of the satellite altimeter data in the China Seas and can provide reliable boundary conditions for the numerical models of the Taiwan Strait tidal motion. Meanwhile, the ocean’s responses to three tropical cyclones (Typhoon Kai-Tak in July 2000, Tropical Storm Russ in June 1994 and Tropical Storm Maria in August-September 2000) in the northern South China Sea have been analyzed using the TOPEX/POSEIDON altimeter data and AVHRR sea surface temperature data. It is indicated that these tropical cyclones could respectively induce a cyclonic eddy in the sea area where the tropical cyclone took a loop form. The eddy appeared after the tropical cyclone’s passage and could last for about two weeks. It also had a cold core with the sea surface temperature difference greater than 2C against its surrounding areas.更多还原