摘要:Several methods have been developed for the estimation of the turbulent Reynolds stress inwavy aquatic environment. They are based on different physical assumptions and often give discrepantresults. It is practically difficult to quantify the uncertainties in these estimations. Using high-resolutionvelocity measurements of acoustic Doppler velocimeter (ADV) from a coastal benthic layer subject to mod-erate wave influence (the ratio of rms wave orbital velocity to current magnitude was 0.23–0.92), this studytests a Synchrosqueezed Wavelet Transform (SWT)-based method and three existing methods (i.e., theCoherence, Cospectra, and Ensemble Empirical Mode Decomposition [EEMD] methods) for wave-turbulencedecomposition. In particular, we evaluate the performance of different methods for objective estimation ofthe turbulent Reynolds stress. Power spectra and cospectra analysis is conducted to quantify the uncertain-ties in the estimations. The results suggest that the Coherence method tends to overestimate the Reynoldsstress due to incomplete removal of wave motions from the observed velocity records; the Cospectramethod performs poorly because the empirical model does not fit the observed cospectra well; both theEEMD and SWT methods underestimate the Reynolds stress, as they tend to attribute turbulent fluctuationsat frequencies in the vicinity of the wave frequencies to wave motions. In general, the SWT method per-forms best inducing lowest uncertainty in the Reynolds stress estimation. For the data set analyzed in thisstudy, the estimations with the Coherence, Cospectra, EEMD, and SWT methods account for 70%, 50%, 51%,and 60% of the total covariance of horizontal and vertical velocities, respectively
全文链接:https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/2017JC013230