2017年辽东湾夏季潮汐锋位置变化的分析

近海潮汐锋的分布和变化,主要受表层风摩擦、底层潮混合、净热通量和浮力平流的影响。基于2017年7、8月份辽东湾东部海域的实测数据,并结合ROMS（Regional Ocean Model System）模拟结果,利用考虑浮力平流效应的Stigebrandt公式对夏季辽东湾潮汐锋的位置变化进行了诊断计算,计算结果与ROMS模拟的潮汐锋位置符合较好,进一步探讨了风、净热通量和浮力平流对锋面位置变化的影响。主要结论如下：（1）位于辽东湾北部和东、西沿岸浅水区的潮汐锋呈"几"字形分布;（2）2017年6-7月潮汐锋位置变动不大,7月份仅在辽东湾东、西两岸潮汐锋位置略微向深水区移动,这主要是净热通量整体略微减小和风场略微增大造成的,浮力平流作用效果不够显著;（3）2017年8月辽东湾潮汐锋位置较7月向深水区大幅移动,最大移动距离约为20km,辽东湾8月份净热通量的大幅减弱起到了重要作用,浮力平流使潮汐锋位置向浅水区偏移,其调节效果比较显著。

VARIATION OF TIDAL FRONT POSITION IN LIAODONG BAY DURING SUMMER 2017

Distribution and variation of tidal front in coastal seas are mainly affected by net heat fluxes, wind friction, tide mixing, and buoyancy advection. Based on the observation in the eastern Liaodong Bay in July and August 2017 and the results obtained from ROMS (Regional Ocean Model System), we use the Stigebrandt formula with the effect of buoyancy advection to diagnostically calculate the position of tidal front in Liaodong Bay. The results are in accordance with those obtained from ROMS. In addition, we discuss the effects of wind, net heat flux, and buoyancy advection on the movement of the tidal front. The main conclusions are as follows. (1) The distribution of tidal front in Liaodong Bay showed an inverse "U" shape, and the tidal front was located in the coastal waters of the northern, eastern, and western Liaodong Bay. (2) From June to July 2017, the position of the tidal front varied insignificantly. In July, the tidal front in the eastern and western coast of Liaodong Bay moved slightly to deep waters due mainly to the slight decrease of net heat flux and weak increase of wind, while the effect of buoyancy advection was not significant. (3) In August 2017, the position of tidal front in Liaodong Bay moved significantly to deep waters with the maximum distance about 20km due to the significant reduction of net heat flux in August. It is evident that buoyant advection shifts the position of the tidal front in August towards shallow waters.