摘要
Abstract
[Objective]To investigate the seasonal characteristics and differences of summer and winter currents in the Yangjiang sea area,and to reveal the law of storm currents dynamics during Typhoon 1907"Wipha",Typhoon 2118"Kompasu",and Typhoon 2203"Chaba",thereby providing support for offshore wind power development and design-parameter assessment in the region.[Method]Based on full-tide observation data collected from Yangjiang coastal area in summer and winter,together with observational data during the three typhoon events,the current characteristics,storm current characteristics were analyzed using harmonic analysis,and the influencing mechanisms were analyzed by combining remote sensing data.[Results and Conclusions]During the full-tide observation periods in summer and winter,the maximum current speeds were 133.4 cm/s and 68.8 cm/s,respectively,with prevailing directions toward the west-southwest.Topography,strong tidal dynamics,the winter northeasterly monsoon,and cold,high-salinity water masses from the north induce seawater convergence in Yangjiang sea area,establishing a strong offshore-directed horizontal pressure-gradient force that drives currents to the southwest-west,during neap tides in summer,when the westward driving force weakens,the sea level is lower,and the flow direction to be more readily controlled by tidal constituents,turning northeastward.Under typhoon forcing,the convergence effect intensifies,when the wind veers eastward and the eastward component exceeds 10.0 m/s,strong southwest-westward currents readily develop,with speed increasing monotonically with the eastward wind component.During the flood period of spring tides,strong currents feature prolonged duration and significant vertical penetration depth.For example,when Typhoon"Chaba"passed through,the maximum speed at station S1 reached 183.9 cm/s,and currents with a speed exceeding 100 cm/s persisted continuously for 8 hours from the surface to the 0.8H(at 0.8 times the total water depth below the sea surface)depth layer.The storm surge set-up in the southern part of the Yangjiang sea area exerts a certain hindrance to the westward current,for example,during Typhoon"Kompasu",despite higher sea level and stronger winds compared to Typhoons"Wipha"and"Chaba",both the duration of strong currents and the depth of influence were relatively smaller.关键词
海流特征/风暴潮流/海水辐聚/阳江海域Key words
current characteristics/storm current/seawater convergence/Yangjiang sea area分类
海洋科学
