Quality Controlling Surf Zone Acoustic Doppler Velocimeter Observations to Estimate the Turbulent Dissipation Rate
Quality Controlling Surf Zone Acoustic Doppler Velocimeter Observations to Estimate the Turbulent Dissipation Rate
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DOI：
10.1175/2010jtecho783.1
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发表时间：
2010-12
影响因子：
2.2
通讯作者：
F. Feddersen
中科院分区：
文献类型：
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作者：
F. Feddersen
高质量的测量湍流耗散率需要诊断现场冲浪区湍流预算。提出了利用声学多普勒测速仪（ADV）资料估算碎波带的质量控制（QC）方法。不良ADV速度数据点用ADV信号强度（SS）和相关性（CORR）两者来诊断。坏SS数据点（dSS）的分数与平均海面以下的波幅归一化换能器距离成反比。当dSS较低时，不良CORR数据点的分数dCORR可以升高。dCORR与平均海面以下的波幅归一化感测体积距离成反比，并且还随着波浪破碎的增加而增加，与湍流和气泡引起的多普勒噪声一致。从“修补"和”内插"时间序列得到的速度谱用于估计。两个QC测试，基于湍流惯性子范围的属性，用于拒绝不良数据运行。第一次测试检查垂直速度谱的幂律指数接近2 5 /3。第二个测试检查水平和垂直速度谱的比率R接近1。在所有dCORR中，70%的修补和插值数据运行通过了这些测试。然而，对于较大的dCORR.0.1（水柱中较高的位置），50%以上的补丁比内插数据未通过QC测试。以前的QC方法设计的波浪研究不适合QC。结果表明，可以一致地估计低于60%的水柱0.1米以上的饱和碎波带内。
High-quality measurements of the turbulent dissipation rate are required to diagnose field surf-zone turbulence budgets. Quality control (QC) methods are presented for estimating surf zone with acoustic Doppler velocimeter (ADV) data. Bad ADV velocity data points are diagnosed with both the ADV signal strength (SS) and correlation (CORR). The fraction of bad SS data points (dSS) depends inversely upon the wave-amplitude-normalized transducer distance below the mean sea surface. The fraction of bad CORR data points dCORR can be elevated when dSS is low. The dCORR depends inversely upon the wave-amplitudenormalized sensing volume distance below the mean sea surface, and also increases with increased wave breaking, consistent with turbulence- and bubble-induced Doppler noise. Velocity spectra derived from both ‘‘patched’’ and ‘‘interpolated’’ time series are used to estimate . Two QC tests, based upon the properties of a turbulent inertial subrange, are used to reject bad data runs. The first test checks that the vertical velocity spectrum’s power-law exponent is near 2 5 /3. The second test checks that a ratio R of horizontal and vertical velocity spectra is near 1. Over all dCORR, 70% of the patched and interpolated data runs pass these tests. However,for larger dCORR .0.1 (locationshigherin the watercolumn),50%more patchedthaninterpolated datarunspasstheQCtests.PreviousQCmethodsdesignedforwavestudiesarenotappropriateforQC.The resultssuggestthatcanbe consistentlyestimatedoverthelower 60%of thewater columnand .0.1 m above the bed within a saturated surf zone.