典型海湾风暴潮增水特征与机理研究

以三门湾为例,基于经验模态分解方法 (EMD)将原始风暴潮增水过程进行分解,并对各个子模态进行能量谱分析,研究每种波动对应的生成机制。结果表明:半封闭海湾内的风暴潮增水较为严重,造成三门湾内强增水的台风为三门湾南侧的西北向登陆台风。EMD分解结果显示三门湾内的风暴潮增水包含6 h,12 h,20 h左右的波动,其中6 h左右的波动来源于海湾共振,共振的频率是由海湾的形状、水深等固有性质所决定的。12 h的波动是由于天文潮与风暴潮耦合作用导致,20 h左右的波动是由于台风移动过程中外海波动的传入。结果表明EMD方法为风暴潮波动增水特征的精细认知提供了一种新的思路和方法,可以加深对海湾内风暴潮波动增水特征的研究。

Characteristics and mechanism of storm surge in typical bay

Taking Sanmen Bay for instance, Empirical Mode Decomposition method ( EMD) was applied to decompose surge data and power spectrum was calculated to study the mechanism of the corresponding model. The results indicate that the storm surge is particularly high and the most powerful path is northwest landing typhoon. Through EMD decomposition, storm surge contains 6 hours, 12 hours, 20 hours period of oscillation. The period of 6 hours due to resonance response in semi-enclosed bay is highly dependent on the bay length and average water depth. The period of 12 hours oscillation results from the interaction of the astronomical tide and storm surge. The period of 20 hours is caused by incoming wave due to typhoon moving process. The research suggests that the EMD method provides a new way of thinking for storm surgecharacteristics and improves the understanding of surge mechanism.