【作者】 邳青岭；

【导师】 胡建宇；

【作者基本信息】 厦门大学 ， 物理海洋学， 2009， 硕士

【摘要】 本文提出一种经改进的基于数学形态学的多尺度、多结构元素、自适应加权的边缘检测方法,该方法能够兼顾大尺度锋面及中、小尺度锋面的检测,并具有很强的抗噪性。通过将该方法应用于高分辨率、长时间序列的遥感海表温度资料,并佐以实测海表温度资料进行分析,本文研究了台湾海峡及其周边海域存在的海表温度锋的季节、月及月内短周期变化规律。经分析,本文共得出以下主要结论:(1)遥感资料分析表明,研究区域内主要存在台湾浅滩锋、浙闽沿岸流锋、彰云海脊锋和东海黑潮锋。(2)受太阳辐射、季风等因素影响,研究海区内海表温度锋存在明显的季节变化,普遍具有冬、春季节强而夏、秋季节弱的特点,冬、春季节锋面的强度和宽度往往大于夏、秋季节。(3)研究海域内的海表温度锋也存在明显的月变化。受季风转向及太阳辐射强弱的影响,4月份和10月份往往是海表温度及其锋面的过渡期:4月份海表温度开始升高,由冬半年向夏半年转换,此时的海表温度锋往往开始减弱;10月份海表温度开始下降,为夏半年向冬半年的转换期,温度锋往往加强。(4)风向的转变对海表温度锋系统的影响十分显著。初步的研究成果表明,风况的改变能够促使浙闽沿岸流、黑潮分支水等表层流系发生变化,进而对研究海区内的海表温度锋产生影响。(5)走航水文观测资料表明,福建近岸海区受冲淡水、东山及平潭地区的上升流、潮汐、浙闽沿岸流等因素的影响,成为海表温度锋的多发区,且近岸区海表温度锋的变化往往比稍靠外海处剧烈。更多还原

【Abstract】 A morphology-based edge detection method is used to study the sea surface temperature(SST) fronts around the Taiwan Strait.The method is based on mathematical morphology,using multi-dimension and multi-structure elements.With this strong anti-noise method,we can distinguish the large thermal fronts as well as the smaller ones.Then we used this method as well as routine method in high resolution and long time series remote sensing SST data to study the thermal fronts and their seasonal,monthly and Intra-monthly variations.Hydrologic data observed along Fujian coast are also used in this study.Followings are the major conclusions:(1) According to analysis of the remote sensing data,there are four major SST fronts in the study area,namely Taiwan Bank Front,Zhe-Min Coastal Front, Zhang-Yun Ridge Front and Kuroshio Front.(2) Affected by solar radiation and monsoon,the thermal fronts in study area have seasonal variations.The fronts in winter and spring are always stronger than those in summer and autumn,both in the SST gradient magnitude and in the frontal range.(3) The thermal fronts in this study area also have monthly variations.April or October is the transition period for SST and fronts.April is the period from the winter-half-year to the summer-half-year,when SST starts to increase but the SST fronts begin to decrease.October is the period from the summer-half-year to the winter-half-year,when SST starts to decrease but the SST fronts increase.(4) Turning of the wind direction has significant effects on SST fronts,and these effects are applied through the sea surface currents such as Zhe-Min Coastal Current and Kuroshio branch.(5) According to the sea surface temperature measured by underway observation system,Fujian coast is regarded as frequent occurrence area of SST front, because of the diluted water,upwellings in Dongshan and Pingtan,tide,and Zhe-Min Coastal Current.The frontal variations in near shore are much more acute than in the offshore regions.更多还原