两类典型台风路径影响下的黄、渤海海浪场特征研究

CHARACTERISTICS OF WAVE FIELD IN THE YELLOW SEA AND THE BOHAI SEA UNDER THE INFLUENCE OF TWO TYPICAL TYPHOONS

台风引起的海浪灾害对我国黄、渤海沿岸影响巨大,严重威胁相关区域人民群众生命财产安全。本文主要利用ERA5(the fifth generation European Center for Medium-Range Weather forecasts atmospheric reanalysis of the global climate)风场研究了两类不同移动路径下的台风(1909号台风“利奇马”和1109号台风“梅花”)在黄、渤海区域的海浪场的时空分布特征及风-浪成长关系。结果表明:两个台风引起的海浪的有效波高空间分布明显不同,波高的分布和风速对应,而海浪周期与风速、波高的分布无明显相关性,波向较风向偏于台风移动方向且两者偏差较大;两个台风进入黄海之前就形成一个从黄海向渤海的“涌浪舌”。海浪成分方面,台风“利奇马”引起的沿海区大浪主要是风浪,而台风“梅花”移动路径的右侧以风浪为主,左侧则主要是涌浪;通过建立无因次波高与无因次周期的幂律关系、以及有效波高关于风速的二次多项式变化关系,研究了风-浪成长特性,结果发现,台风浪的成长特性与台风过程关系不明显,但与所处水域的水深和海底地形地貌有关,表现为两个台风在黄海区域的台风浪成长较渤海区域更为充分。

Typhoon-induced wave disasters often result in huge economic and social losses in the coastal areas of the Yellow Sea and the Bohai Sea in China.Using ERA5(the fifth generation European Center for Medium-Range Weather forecasts atmospheric reanalysis of the global climate)wind field data,we studied the transit characteristics of temporal and spatial distribution of wave field,and established numerical wind-waves relationship during two typical typhoons(No.1909 typhoon Lekima and No.1109 typhoon Muifa)in the Yellow Sea and the Bohai Sea.The results show that the spatial distribution of significant wave height caused by the two typhoons was obviously different.The distribution of wave height corresponded to the wind speed,while the distribution of wave period had no obvious correlation with the distribution of wind speed and wave height.The wave direction was more windward than the direction of typhoon movement,and the deviation between the two was large.Before the two typhoons entered the Yellow Sea,a swell tongue was formed in the Yellow Sea to the Bohai Sea.In terms of wave component,the coastal waves caused by typhoon Lekima were mainly wind waves.The major waves on the right side of the track of typhoon Muifa were wind waves,while those on the left side were swell.By establishing the power-law relationship between dimensionless wave height and dimensionless period,and the quadratic polynomial relationship between significant wave height and wind speed,the growth characteristics of wind-waves were studied.The results show that the characteristics of typhoon wave growth were not obviously related to the typhoon course,but related to the relief and the depth of the region where typhoon passed,showing that the growth of typhoon waves in the Yellow Sea was more sufficient than that in the Bohai Sea.