Suppression of Internal Wave Breaking in the Antarctic Circumpolar Current near Topography
Suppression of Internal Wave Breaking in the Antarctic Circumpolar Current near Topography
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DOI：
10.1175/jpo-d-12-0154.1
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发表时间：
2014-04
影响因子：
3.5
通讯作者：
S. Waterman;K. Polzin;A. N. Garabato;K. Sheen;A. Forryan
中科院分区：
文献类型：
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作者：
S. Waterman;K. Polzin;A. N. Garabato;K. Sheen;A. Forryan
摘要
对湍流的全深度微观结构测量以及速度和密度的细结构测量进行了分析，以研究南极绕极流中湍流与内波场之间的关系。这些数据显示，在某些特定位置，细尺度参数化方法对湍动能耗散率存在系统性的近底高估。近底高估的区域通常具有近底流速大以及地形粗糙度高的特征。此外，在这些位置发现剪切 - 应变比低于平均水平，这表明近惯性波场较弱，旋转谱表明向上的内波能量传播占主导，并且在垂直波长约为100米处窄带方差增强。最后，基于背景流的近底剪切以及具有……的背景流，细尺度高估通常与弗劳德数升高有关。
AbstractSimultaneous full-depth microstructure measurements of turbulence and finestructure measurements of velocity and density are analyzed to investigate the relationship between turbulence and the internal wave field in the Antarctic Circumpolar Current. These data reveal a systematic near-bottom overprediction of the turbulent kinetic energy dissipation rate by finescale parameterization methods in select locations. Sites of near-bottom overprediction are typically characterized by large near-bottom flow speeds and elevated topographic roughness. Further, lower-than-average shear-to-strain ratios indicative of a less near-inertial wave field, rotary spectra suggesting a predominance of upward internal wave energy propagation, and enhanced narrowband variance at vertical wavelengths on the order of 100 m are found at these locations. Finally, finescale overprediction is typically associated with elevated Froude numbers based on the near-bottom shear of the background flow, and a background flow with a...