冬季大风对渤海海峡水体通量的影响研究

The Effect of the Winter Wind Storm on Water Flux in Bohai Strait

基于FVCOM模型,通过七套不同风场再分析数据,对2017年冬季渤黄海的海洋水文动力环境进行了模拟。模拟结果与实测资料对比,发现ECMWF Reanalysis v5_1HR(以下简称ERA5_1HR)风场数据可以对渤黄海冬季水文环境实现最优化模拟。并发现2017年2月17—24日大风事件发生时,渤海和北黄海海流会随大风暴发和松弛流出和流入渤海海峡。出流现象主要出现在渤海海峡的南通道和中间通道,入流现象初期主要出现在北通道,随着时间的推移整个渤海海峡都有入流现象。在此期间水位呈周期性变化,在大风事件发生时渤海水会向南部堆积呈现南高北低的现象,大风松弛时,渤海水位呈现北高南低的现象。大风期间急剧的流入流出过程显著增强渤海的水交换,三次高频大风过程造成的出水通量分别是18.35×10^(6)m^(3)、32.46×10^(6)m^(3)和34.15×10^(6)m^(3);入水通量分别是21.11×10^(6)m^(3)、38.69×10^(6)m^(3)和22.38×10^(6)m^(3)。两个对照实验结果显示,在大风期间风应力才是主导渤海环流和水交换的最重要因素。

Based on FVCOM model,we compared seven sets of different wind field reanalysis data and used them to simulate the marine environment of the Bohai and Yellow Sea in the winter of 2017.Comparing the model’s results with the observed data,it was found that ECMWF Reanalysis V5_1HR(hereinafter referred to as ERA5_1HR)can optimize the hydrological environment of the Bohai and Yellow Sea in winter.During the winter storm from February 17 to February 24,2017,it was also found that the currents in the Bohai and North Yellow Sea would outflow and inflow through the Bohai Strait with the winter storm burst and relaxation.The outflow mainly occurred in the southern and middle part of the Bohai Strait.And the inflow mainly occurred in the northern part at first,then occurred in the whole Bohai Strait.During the wind storm,the water level changes periodically.When a wind storm burst the water in the Bohai Sea would be accumulated to the southern part.At this time the sea level was high in the southern part and low in the northern part of the Bohai Sea.When the wind storm was relaxed,the sea level in the Bohai Sea was opposite.The rapid inflow and outflow process during the wind storm period significantly enhanced the water exchange in the Bohai Sea.The outflow fluxes caused by the three high-frequency wind storms processes were 18.35×10^(6) m^(3),32.46×10^(6) m^(3) and 34.15×10^(6) m^(3) respectively;The inflow fluxes are 21.11×10^(6) m^(3),38.69×10^(6) m^(3) and 22.38×10^(6) m^(3) respectively.According to the results of two controlled experiments,the wind speed is the most important factor dominating the circulation and water exchange in the Bohai Sea during the wind storms.