Variability and sources of the internal wave continuum examined from global moored velocity records
Variability and sources of the internal wave continuum examined from global moored velocity records
复制标题
从全球系泊速度记录检查内波连续体的变化和来源
DOI：
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发表时间：
2021
影响因子：
3.5
通讯作者：
M. Alford
中科院分区：
文献类型：
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作者：
A. L. Boyer;M. Alford
海洋湍流的能量被认为从其假定来源（即中尺度涡流、近惯性内波和内潮汐）转移到内波连续体，并通过连续体通过共振三元组相互作用传递到破碎尺度。为了检验这些想法，通过计算来自部署在 1362 个独立系泊处的 2260 个海流仪表记录的全球数据库的时间相关旋转频谱来检查海洋内部重力波连续谱的水平和变化。计算连续体和三个“源带”（近惯性、潮汐和中尺度）中的能量时间序列，并检查它们的变异性和协变性。在上层海洋中可以看到连续体的季节调制高达 5 倍，这表明风驱动的近惯性波是一个重要的来源。发现连续体的时间序列与近惯性峰值的相关性比与半日或中尺度的相关性更强。探索了使用系泊内波动能频谱作为 Gregg-Henyey-Polzin 精细尺度参数化中传统剪切或应变波数谱的替代输入，并与传统的基于应变的估计进行了比较。
Energy for ocean turbulence is thought to be transferred from its presumed sources (namely, the mesoscale eddy field, near-inertial internal waves and internal tides) to the internal wave continuum, and through the continuum via resonant triad interactions to breaking scales. To test these ideas, the level and variability of the oceanic internal gravity wave continuum spectrum are examined by computing time-dependent rotary spectra from a global database of 2260 current meter records deployed on 1362 separate moorings. Time series of energy in the continuum and the three “source bands” (near-inertial, tidal and mesoscale) are computed, and their variability and covariability examined. Seasonal modulation of the continuum by factors of up to 5 is seen in the upper ocean, implicating wind-driven near-inertial waves as an important source. The time series of the continuum is found to correlate more strongly with the near-inertial peak than with the semi-diurnal or mesoscale. The use of moored internal-wave kinetic energy frequency spectra as an alternate input to the traditional shear or strain wavenumber spectra in the Gregg-Henyey-Polzin finescale parameterization is explored and compared to traditional strain-based estimates.