相似路径台风风暴潮过程对比

Comparative study on storm surge processes caused by typhoons with similar tracks

基于MIKE 21模型和Holland台风风场模型,构建了1909号利奇马和0509号麦莎2次相似路径台风期间的风场和气压场,并模拟了相应的风暴潮过程。结果表明:台风中心附近增水变化显著,浙江东北部海域在台风登陆期间的增水更大;受台风强度影响,台风利奇马期间增水高值区更大,部分海域2次台风期间最大增水差值接近1.0 m;潮致欧拉余流速度较大值主要分布在100 m水深以浅的海域,量值超过20 cm/s,江苏沿海、台湾东北部海域存在欧拉余环流;台风利奇马期间近海斯托克斯余流值普遍小于麦莎期间;斯托克斯余流项对台风期间长江口、浙闽等近海浅水区短期物质输运过程起一定主导作用。用EMD方法和Hillbert变换分析了典型站点风暴潮位的特征,发现站点IMF1模态和天文潮位较吻合;水深和IMF3模态的最大功率谱密度呈现出较高的相关性,并且随着水深的增加,IMF3模态的最大功率谱密度逐步变大。

Based on MIKE 21 model and Holland typhoon wind field model,the wind field and pressure field during No.1909 Typhoon Lekima and No.0509 Typhoon Matsa are constructed,and the corresponding storm surge process is simulated.The results show that the increase of water near the typhoon center changes significantly and the storm surge in the northeast of Zhejiang Province is greater during the typhoon landing.Affected by the typhoon intensity,the high value area of storm surge during Typhoon Lekima is larger,and the maximum difference of storm surge during two typhoons in some sea areas is close to 1.0 m.The large value of tidal Euler residual current is mainly distributed in the sea area within a depth of 100 m and a velocity of more than 20 cm/s.Meanwhile,the Euler residual circulation exists in the coastal sea areas of Jiangsu Province and the northeastern sea areas of Taiwan Province.The value of Stokes residual current in the offshore during Typhoon Lekima is generally lower than that during Typhoon Matsa.The Stokes residual current term plays a certain leading role in the short-term transport process of net material in the coastal shallow water areas such as the Yangtze River Estuary,Zhejiang Province and Fujian Province during the typhoon.The empirical mode decomposition(EMD)method and Hilbert transform are used to analyze the characteristics of storm tide level at typical stations.It is found that the IMF1 mode at stations is in good agreement with the astronomical tide level.The water depth and the maximum power spectral density of IMF3 mode show a high correlation,and with the increase of water depth,the maximum power spectral density of IMF3 mode gradually increases.