台湾海峡寒害事件机制研究

2008年2月，澎湖海域突现大量冷水，致使大量鱼类被冻死，称为寒害事件。初步研究表明此冷水是在高强度，长时期的东北季风作用下从浙闽沿岸流离岸分离，再向南入侵到澎湖海域。正常情况下，浙闽沿岸流在东北风导致的Ekman作用下理应向西贴岸南流。因此，浙闽沿岸流的冷水的离岸分离及南侵澎湖的机制值得进行研究。风场时空变化、平潭岛的凸岸作用、海底地形的引导以及海峡南北水位及流系的差异，加上冷空气爆发后黄、东海的传入海峡的沿岸陷波都有可能是冷水分离及入侵澎湖的原因。利用台湾海峡布设的地波雷达、浮标所监测的长时间序列温、盐、流资料，结合遥感资料、现场航次及已业务化的三维海洋模型，研究浙闽沿岸流分离并入侵到澎湖海域的动力学机制，及与其有关的年代际的环流变异是本课题的研究内容。该研究有助于加强对极端灾害的预防和提高对台湾海峡动力过程的理解。

In 2008, a large amount of cold water intruded into Penghu Island (PHI), causing great losses to local aquaculture and the coral reef ecosystem, called cold disaster. Recent studies show that the northeasterly monsoon of long period and high intensity drives the cold water eastward offshore first and then southward intrusion and results in the cold disaster. Normally, China Coastal Current (CCC) should flow southward along the coastline through Ekman effect. Therefore, the mechanisms of eastward offshore current and southward intrusion should be studied. Wind variation, cape boundary, bottom topography, the meridian water level gradient and the southward trapped wave generated by the outbreak of the north wind may be related with the cold water separating from the coast and intruding into PHI. With the use of long time series data from HF radar, mooring buoys in the Taiwan Strait (TWS), collecting the observation data and the remote sensing data in the TWS, analyzing the results from the operational three-dimensional ocean model, the mechanisms of the CCC separation and intrusion, and the related global circulation anomalies will be studied. The research can make it more available to predict the cold disasters, and enhance the understanding of the regional ocean dynamics in the TWS.