Observation of a Large Lee Wave in the Drake Passage
Observation of a Large Lee Wave in the Drake Passage
复制标题
DOI：
10.1175/jpo-d-16-0153.1
复制
发表时间：
2017-03
影响因子：
3.5
通讯作者：
J. Cusack;A. N. Garabato;D. Smeed;J. Girton
中科院分区：
文献类型：
--
作者：
J. Cusack;A. N. Garabato;D. Smeed;J. Girton
摘要背风波被认为在南大洋动力学中起着重要作用，它促进了能量从南极绕极流的射流向微尺度湍流运动的转移，这对水体的变化很重要。在贯向和等密度混合实验（DIMES）期间，部署在德雷克海峡的两个EM-APEX剖面浮标独立测量了沙克尔顿断裂带上方120 ± 20 m的垂直振幅背风波。稳定EM-APEX运动的模型被开发来计算绝对垂直水速度，增加由浮子所做的水平速度测量。波的三个速度分量的波动都超过15 cm s−1，其固有频率接近当地浮力频率。观测到波以1.3 ± 0.2 W m−2和8 ± 1 N m−2的峰值速率垂直传输能量和水平动量。湍流动能耗散率估计使用索普尺度和方法，隔离…
AbstractLee waves are thought to play a prominent role in Southern Ocean dynamics, facilitating a transfer of energy from the jets of the Antarctic Circumpolar Current to microscale, turbulent motions important in water mass transformations. Two EM-APEX profiling floats deployed in the Drake Passage during the Diapycnal and Isopycnal Mixing Experiment (DIMES) independently measured a 120 ± 20-m vertical amplitude lee wave over the Shackleton Fracture Zone. A model for steady EM-APEX motion is developed to calculate absolute vertical water velocity, augmenting the horizontal velocity measurements made by the floats. The wave exhibits fluctuations in all three velocity components of over 15 cm s−1 and an intrinsic frequency close to the local buoyancy frequency. The wave is observed to transport energy and horizontal momentum vertically at respective peak rates of 1.3 ± 0.2 W m−2 and 8 ± 1 N m−2. The rate of turbulent kinetic energy dissipation is estimated using both Thorpe scales and a method that isolate...