DOI: 10.1029/2017JC013731
Scopus记录号: 2-s2.0-85052530180
论文题名: Measuring the Dissipation Rate of Turbulent Kinetic Energy in Strongly Stratified, Low-Energy Environments: A Case Study From the Arctic Ocean
作者: Scheifele B. ; Waterman S. ; Merckelbach L. ; Carpenter J.R.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 8 起始页码: 5459
结束页码: 5480
语种: 英语
英文关键词: Arctic Ocean
; Beaufort Sea
; ocean microstructure glider
; ocean turbulence
; shear microstructure
; temperature microstructure
英文摘要: We compare estimates of the turbulent dissipation rate, ε, obtained independently from coincident measurements of shear and temperature microstructure in the southeastern Beaufort Sea, a strongly stratified, low-energy environment. The measurements were collected over 10 days in 2015 by an ocean glider equipped with microstructure instrumentation; they yield 28,575 shear-derived and 21,577 temperature-derived ε estimates. We find agreement within a factor of 2 from the two types of estimates when ε exceeds 3 × 10−11 W/kg, a threshold we identify as the noise floor of the shear-derived estimates. However, the temperature-derived estimates suggest that the dissipation rate is lower than this threshold in 58% of our observations. Further, the noise floor of the shear measurements artificially skews the statistical distribution of ε below 10−10 W/kg, that is, in 70% of our observations. The shear measurements overestimate portions of the geometric mean vertical profile of ε by more than an order of magnitude and underestimate the overall variability of ε by at least 2 orders of magnitude. We further discuss uncertainties that arise in both temperature- and shear-derived ε estimates in strongly stratified, weakly turbulent conditions, and we demonstrate how turbulence spectra are systematically modified by stratification under these conditions. Using evidence from the temperature-gradient spectral shapes and from the observed ε distributions, we suggest that the temperature-derived dissipation rates are reliable to values as small as 2 × 10−12 W/kg, making them preferable for characterizing the turbulent dissipation rates in the weakly turbulent environment of this study. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113434
Appears in Collections: 气候减缓与适应
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作者单位: Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada; Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
Recommended Citation:
Scheifele B.,Waterman S.,Merckelbach L.,et al. Measuring the Dissipation Rate of Turbulent Kinetic Energy in Strongly Stratified, Low-Energy Environments: A Case Study From the Arctic Ocean[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(8)