EMD方法在中国沿岸风暴潮增水分析中的应用  

Application of the EMD method in the storm surges at the coast of China

作　　者：杨金湘 袁方超 李郅明 吴向荣 

机构地区：[1]厦门海洋预报台,福建厦门361008

出　　处：《海洋通报》2016年第2期157-162,169,共7页Marine Science Bulletin

基　　金：国家海洋局东海分局青年基金(201322)

摘　　要：海岸是风暴潮发生的区域,由于该区域位于大气、海洋、陆地的交汇处,受到多种因素的共同影响,因此风暴潮过程的机理复杂。通常当风暴增水叠加在正常的天文高潮时,引发最为严重的影响。利用经验模态分解(EMD-Empirical Mode Decomposition)的方法,对中国沿海的潮位站的水位波进行分解。EMD分解得到的增水曲线与低通滤波后的调和分析的增水曲线基本一致。利用该方法,进一步的分析台风造成的福建沿海测站的风暴增水的异同。结果表明:台风经过台湾海峡南、北部和进入海峡时,都会造成福建沿岸各站的增水,增水的幅度与各站距离台风中心的距离有关,各站的增水时间差异很小。然而,通过两次热带气旋期间中国东部沿岸多个潮位站的分析发现,台风在东海产生的增水会以开尔文波的形式传播进入台湾海峡,造成福建沿岸异常的增水现象。Storm surges usually occur at the coasts, which are the interactive boundaries of the atmosphere, ocean and land, making the mechanism of the storm surge more complicatedly affected by many factors. Usually the storm surge superposed with the spring tide may cause a severe damage. In this study, the Empirical Mode Decomposition（EMD）method is adopted to decompose the recoded sea elevation data at the stations along the coast of China. It shows the EMD derived storm surge data agree well with the low-pass filtered storm surge data derived from the harmonic analysis method. Furthermore, the method is applied in the comparison of typhoon induced storm surges at the Fujian coast. The results show the typhoon will cause the storm surges at the stations along the Fujian coast while it passes from the south and north of the Taiwan Strait or enters the strait. The amplitude of the storm surge at each station depends on the distance between the station and the typhoon center, but the time lag is small between different stations. However, by analyzing more storm surges at stations along the east coast of China during the two tropical cyclone periods, it finds that the typhoon induced storm surge at the northeast coast of China will propagate southward into the Taiwan Strait in the way of coastal Kelvin Wave, leading to the hysteretic anomalous surge at the Strait.

关 键 词：台风 EMD 风暴增水 开尔文波 

分 类 号：P731.3[天文地球—海洋科学]