Effect of background parabolic current on characteristics and energetics of internal solitary waves by numerical simulation
Effect of background parabolic current on characteristics and energetics of internal solitary waves by numerical simulation
复制标题
数值模拟背景抛物线电流对内孤立波特性和能量学的影响
DOI：
10.1007/s13131-016-0790-4
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发表时间：
2016
影响因子：
1.4
通讯作者：
Cai Shuqun
中科院分区：
文献类型：
--
作者：
Lu Haibin;Xie Jieshuo;Yao Yuan;Xu Jiexin;Chen Zhiwu;He Yinghui;Cai Shuqun
在对南海东北部中国上层观测背景抛物线流进行修正的基础上，利用内重力波模式研究了8种背景流对内孤立波特征和能量转换的影响。结果表明，虽然背景电流对产生的间歇波个数影响不大，但会降低产生的间歇波的相速。当背景抛物线流下边界在主温跃层附近或以上时，等压线的振幅和最大位移深度增大；当背景抛物线流曲率减小时，斜压线的振幅和斜压与正压能量之比减小，而斜压线的相速、斜压能量和斜压动能与有效势能之比增大；背景抛物线下界向下延伸至海床，背景流曲率减小，等压线的振幅和相速减小，正压动能、斜压能量和斜压动能与有效势能之比增大。在整个深度上，当下背景流曲率减小，上背景流曲率增大时，ISW波幅、相速度、斜压能量与正压能量之比、斜压能量、KE与APE之比均增大。
Based on modifications of the observed background parabolic current in upper layer of the northeastern South China Sea (SCS), the effects of eight kinds of background currents on the characteristics and energy conversion of internal solitary waves (ISWs) are investigated by an Internal Gravity Wave (IGW) model. It is found that, although the background current has little effect on the number of the generated ISWs, it reduces the resulted phase speed of ISW. When the background parabolic current appears with its lower boundary near or above the main thermocline, the ISW amplitude and the depth of the isopycnal undergoing maximum displacement increase; when the background parabolic current curvature is reduced, the ISW amplitude and the ratio of baroclinic to barotropic energy reduce, whilst the phase speed of ISW, the baroclinic energy, and the ratio of baroclinic kinetic energy (KE) to available potential energy (APE) increase; when the lower boundary of background parabolic current extends down to the seabed and the background current curvature is reduced, the ISW amplitude and phase speed decrease, whilst the barotropic kinetic energy, the baroclinic energy and the ratio of KE to APE increase. At a whole depth, when the lower background current curvature is reduced and the upper current curvature is increased, the ISW amplitude, and phase speed, the ratio of baroclinic to barotropic energy, the baroclinic energy, and the ratio of KE to APE all increase.