摘要
根据在青岛附近海域开展的现场观测数据介绍了一种可能的新的第二模内孤立波的产生机制。温度链观测数据显示在2 h内孤立波特征由显著的第一模内孤立波变为了显著的第二模内孤立波。所观测到的第二模内孤立波的波面起伏和它的垂直结构同KdV(Korteweg-de Vries)方程的理论结果吻合良好,对应涨潮引起的内波非线性系数、频散系数以及Ursell数的变化和第二模内孤立波的产生相匹配。这些结果表明,所观测到的第二模内孤立波可能是由于涨潮导致的局地层结快速变化引起的。进一步分析表明,局地层结快速变化可能由潮汐推动黄海冷水团边缘锋面移动引起。
Although the energy of mode-2 internal solitary waves(ISWs) is 10~100 times less than that of mode 1 ISWs, the turbulent dissipation rate of it is comparable to that of mode 1 ISWs because of its more complicated vertical structure. We here reported a new possible mode 2 ISW generation scenario based on the field observation conducted in Qingdao coastal waters in the Yellow Sea. A thermistor chain recorded a second baroclinic mode(mode 2) ISW following the first baroclinic mode(mode 1) ISWs in about two hours. Wave displacement of the mode 2 ISW and its vertical structure can be well described by weakly nonlinear Korteweg-de Vries(KdV) theory. The variation of nonlinearity coefficient, dispersion coefficient, and Ursell number caused by rising tide were consistent with generation of the mode 2 ISW. These results indicate that the observed generation of mode 2 ISWs should be mainly caused by the change in vertical stratification induced by the rising tide, which moves the temperature front of the Yellow Sea Cold Water Mass towards the observation station and elevates the thermocline.
作者
杨光兵
郭延良
于龙
陈亮
YANG Guang-bing;GUO Yan-liang;YU Long;CHEN Liang(Key Laboratory of Marine Science and Numerical Modeling,First Institute of Oceanography,MNR,Qingdao 266061,China;Laboratory for Regional Oceanography and Numerical Modeling,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China;College of Oceanic and Atmospheric Sciences,Ocean University of China,Qingdao 266100,China)
出处
《海洋科学进展》
CAS
CSCD
北大核心
2020年第1期21-27,共7页
Advances in Marine Science
基金
中央级公益性科研院所基本科研业务费专项资金资助项目——海底浅表层底质温度剖面和声速连续观测技术研究和应用(2017Q01)
黄海东北部开敞性海湾余流特征及形成机制研究(2015P02)
国家自然科学基金项目——天气过程中底层水温变化对浅表层底质影响的观测研究(41706038)
山东省自然科学基金项目——海底浅表层底质温度剖面和声速连续观测系统研究(ZR2017QD005)。
关键词
第二模内孤立波
潮汐
KDV方程
现场观测
mode-2 internal solitary wave
tide
KdV equation
field observation
