大亚湾海域潮位“双峰”现象生成机制研究  

The Generation Mechanism of the Double Peak Tidal Elevation in Daya Bay

作　　者：刁希梁 丁扬[2] 鲍献文 

机构地区：[1]中国海洋大学海洋与大气学院,山东青岛266100 [2]中国海洋大学物理海洋教育部重点实验室,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2017年第9期1-10,共10页Periodical of Ocean University of China

基　　金：国家重点基础研究发展计划项目(2015CB452900)资助~~

摘　　要：大亚湾海域的潮位观测数据呈现出明显的"双峰"现象,在调和分析并选用分潮重构的过程中发现M_6分潮的异常增长是引起大亚湾内部出现该现象的主要原因,并且在湾口至湾顶两个测站之间M_6分潮增长了自身的近两倍。本文首先分析构建的FVCOM数值模型得到的M_6同潮图,发现M_6分潮在计算海域存在两个无潮点,一个位于湾外开边界附近,另一个位于东侧的陆地上,这与矩形等深渠道共振理论中在1/4,3/4处出现无潮点的理论是相符的,只是实际情况中由于浅水效应的影响,湾口处的无潮点被迫转移到陆地上。进一步进行了三组数值实验:改变水深和湾长后,大亚湾内的共振条件被破坏,M_6潮高均显著减小,证明共振效应确实是引起该分潮增大的原因;能量来源实验表明:M_6分潮的成长72%来源于自身成长,4.6%来源于M_2分潮非线性转化,23.4%来源于M_2和M_4分潮相互作用转化;若除去二次底摩擦,M_6分潮就不能通过各种非线性作用攫取能量,共振放大作用也就发挥不了任何作用。The observation data in the Daya Bay shows the double peak tide phenomenon, and the har- monic analysis reveals that M6 tide＇s significant growth is the main cause of this phenomenon and it doubles itself between the two observation stations. According to the M6 cotidal chart, which is based on the established FVCOM model in Daya Bay, we can find that there are two amphidromic points in this area, one is near the open boundary and the other is located on the land of the right side of the estu- ary. This can be explain by the resonance effect happened in a straight channel with constant water depth, the amphidromic points will located to the 1/4 and 3/4 of the wave length. But as the shoaling effect in the reality, the first point is forced to move onto the land. Three group of numerical experi- ments have been done. after the depth and length of the bay are changed, the resonance condition will be changed, and the result is M6 tide＇s height decrease significantly, which proves that the resonance effect is the main cause of the M6 abnormal growth. And the energy distribution of the M6 growth： 72% come from it own amplification, while 4.6 ~ come from nonlinear effect and 23.4~ come from the M2 and M4 mutual effect. When the quarter bottom friction transformed in to linear form, the M6 tide can not get energy from other tides through the nonlinear effect and then the resonance effect could not function as well.

关 键 词：大亚湾 M6分潮 潮汐共振 FVCOM 数值实验 

分 类 号：P595[天文地球—地球化学]