渤中浅滩对渤海夏季底层冷水带的影响

Influence of the Central Bohai Shoal on the Bottom Cold Water Belt in Summer

本文基于有限体积海洋模式(Finite volume coastal ocean model,FVCOM),模拟了2016年夏季渤海温度场的三维结构,准确刻画了夏季渤海底层以渤中浅滩为暖中心,四周被冷水包围的温度分布特征(渤海夏季底层冷水带),再现了渤海夏季底层“非对称双中心冷水”结构。在此基础上,通过保守物质示踪实验以及拉格朗日粒子追踪实验分析了渤海夏季底层冷水带的来源;通过地形实验分析了渤海夏季底层冷水带的形成机制,讨论了渤中浅滩对渤海夏季底层冷水带的影响。结果表明,渤海夏季底层冷水带中的低温水主要为渤海冬季残留冷水,北黄海冷水入侵也对其有一定贡献;渤中浅滩水深较浅、四周较深的地形差异是形成渤海夏季底层冷水带的主要原因。

Based on the Finite Volume Coastal Ocean Model(FVCOM),this paper simulated the three-dimensional structure of the temperature field in the Bohai Sea in the summer of 2016,and accurately described the temperature distribution characteristics of the bottom layer of the Bohai Sea in summer,with the Central Bohai shoal as the warm center and surrounded by cold water(Bottom Cold Water Belt in Summer,BCWBS).The structure of"the asymmetric dual-center cold water"in the bottom layer of Bohai Sea in summer is reproduced.On this basis,the source of the BCWBS was analyzed by the conserved material tracing experiment and Lagrange particle tracking experiment,the formation mechanism of BCWBS is analyzed by topographic experiments,and the influence of the Central Bohai shoal on BCWBS is discussed.The results show that the low temperature water of BCWBS is mainly the residual cold water of the Bohai Sea in winter,the cold water intrusion from the North Yellow Sea also contributed to it.The shallow water depth of the Central Bohai shoal and the deeper topographic difference around the Central Bohai shoal are the main reasons for the formation of BCWBS.