Estimation of turbulence dissipation rate and its variability from sonic anemometer and wind Doppler lidar during the XPIA field campaign

Abstract. Despite turbulence being a fundamental transport process in the boundary layer, the capability of current numerical models to represent it is undermined by the limits of the adopted assumptions, notably that of local equilibrium. Here we leverage the potential of extensive observations in determining the variability in turbulence dissipation rate (ϵ). These observations can provide insights towards the understanding of the scales at which the major assumption of local equilibrium between generation and dissipation of turbulence is invalid. Typically, observations of ϵ require time- and labor-intensive measurements from sonic and/or hot-wire anemometers. We explore the capability of wind Doppler lidars to provide measurements of ϵ. We refine and extend an existing method to accommodate different atmospheric stability conditions. To validate our approach, we estimate ϵ from four wind Doppler lidars during the 3-month XPIA campaign at the Boulder Atmospheric Observatory (Colorado), and we assess the uncertainty of the proposed method by data intercomparison with sonic anemometer measurements of ϵ. Our analysis of this extensive dataset provides understanding of the climatology of turbulence dissipation over the course of the campaign. Further, the variability in ϵ with atmospheric stability, height, and wind speed is also assessed. Finally, we present how ϵ increases as nocturnal turbulence is generated during low-level jet events.

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Estimation of turbulence dissipation rate and its variability from sonic anemometer and wind Doppler lidar during the XPIA field campaign

10.5194/amt-2018-80 ◽

2018 ◽

Author(s):

Nicola Bodini ◽

Julie K. Lundquist ◽

Rob K. Newsom

Keyword(s):

Transport Process ◽

Dissipation Rate ◽

Numerical Models ◽

Local Equilibrium ◽

Sonic Anemometer ◽

Atmospheric Stability ◽

Doppler Lidar ◽

Hot Wire ◽

Require Time ◽

Low Level Jet

Abstract. Despite turbulence being a fundamental transport process in the boundary layer, the capability of current numerical models to represent it is undermined by the limits of the adopted assumptions, notably that of local equilibrium. Here we leverage the potential of extensive observations in determining the variability of turbulence dissipation rate (ε). These observations can provide insights towards the understanding of the scales at which the major assumption of local equilibrium between generation and dissipation of turbulence is invalid. Typically, observations of ε require time- and labor-intensive measurements from sonic and/or hot-wire anemometers. We explore the capability of wind Doppler lidars to provide measurements of ε. We refine and extend an existing method to accommodate different atmospheric stability conditions. To validate our approach, we estimate ε from four wind Doppler lidars during the 3-month XPIA campaign at the Boulder Atmospheric Observatory (Colorado), and we assess the uncertainty of the proposed method by data inter-comparison with sonic anemometer measurements of ε. Our analysis of this extensive dataset provides understanding of the climatology of turbulence dissipation over the course of the campaign. Further, the variability of ε with atmospheric stability, height, and wind speed is also assessed. Finally, we present how ε increases as nocturnal turbulence is generated during low-level jet events.

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Horizontal-Velocity and Variance Measurements in the Stable Boundary Layer Using Doppler Lidar: Sensitivity to Averaging Procedures

Journal of Atmospheric and Oceanic Technology ◽

10.1175/2008jtecha988.1 ◽

2008 ◽

Vol 25 (8) ◽

pp. 1307-1327 ◽

Cited By ~ 41

Author(s):

Yelena L. Pichugina ◽

Sara C. Tucker ◽

Robert M. Banta ◽

W. Alan Brewer ◽

Neil D. Kelley ◽

...

Keyword(s):

Boundary Layer ◽

Stable Boundary Layer ◽

Sonic Anemometer ◽

Correlation Coefficients ◽

Doppler Lidar ◽

High Wind ◽

Stable Boundary ◽

Mean Wind Speed ◽

The Mean ◽

Low Level Jet

Abstract Quantitative data on turbulence variables aloft—above the region of the atmosphere conveniently measured from towers—have been an important but difficult measurement need for advancing understanding and modeling of the stable boundary layer (SBL). Vertical profiles of streamwise velocity variances obtained from NOAA’s high-resolution Doppler lidar (HRDL), which have been shown to be approximately equal to turbulence kinetic energy (TKE) for stable conditions, are a measure of the turbulence in the SBL. In the present study, the mean horizontal wind component U and variance σ2u were computed from HRDL measurements of the line-of-sight (LOS) velocity using a method described by Banta et al., which uses an elevation (vertical slice) scanning technique. The method was tested on datasets obtained during the Lamar Low-Level Jet Project (LLLJP) carried out in early September 2003, near the town of Lamar in southeastern Colorado. This paper compares U with mean wind speed obtained from sodar and sonic anemometer measurements. The results for the mean U and mean wind speed measured by sodar and in situ instruments for all nights of LLLJP show high correlation (0.71–0.97), independent of sampling strategies and averaging procedures, and correlation coefficients consistently >0.9 for four high-wind nights, when the low-level jet speeds exceeded 15 m s−1 at some time during the night. Comparison of estimates of variance, on the other hand, proved sensitive to both the spatial and temporal averaging parameters. Several series of averaging tests are described, to find the best correlation between TKE calculated from sonic anemometer data at several tower levels and lidar measurements of horizontal-velocity variance σ2u. Because of the nonstationarity of the SBL data, the best results were obtained when the velocity data were first averaged over intervals of 1 min, and then further averaged over 3–15 consecutive 1-min intervals, with best results for the 10- and 15-min averaging periods. For these cases, correlation coefficients exceeded 0.9. As a part of the analysis, Eulerian integral time scales (τ) were estimated for the four high-wind nights. Time series of τ through each night indicated erratic behavior consistent with the nonstationarity. Histograms of τ showed a mode at 4–5 s, but frequent occurrences of larger τ values, mostly between 10 and 100 s.

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Characteristics of Energy Dissipation Rate Observed from the High-Frequency Sonic Anemometer at Boseong, South Korea

Atmosphere ◽

10.3390/atmos12070837 ◽

2021 ◽

Vol 12 (7) ◽

pp. 837

Author(s):

Jeonghoe Kim ◽

Jung-Hoon Kim ◽

Robert D. Sharman

Keyword(s):

South Korea ◽

High Frequency ◽

Dissipation Rate ◽

Sonic Anemometer ◽

Atmospheric Stability ◽

Turbulence Theory ◽

Estimation Methods ◽

The Third ◽

Sonic Anemometers ◽

Meteorological Observatory

The characteristics of low-level turbulence at Boseong, located on the southern coast of South Korea, were investigated in terms of eddy dissipation rate (EDR) using 1-year (2018) of wind data obtained from the Boseong Meteorological Observatory (BMO), a World Meteorological Organization testbed. At BMO, a 307 m tall tower is installed on which four high-frequency (20 Hz) sonic anemometers are mounted at 60, 140, and 300 m above ground level (AGL). In addition, a sonic anemometer at 2.5 m AGL is located to the south of the tower. EDRs are estimated from the wind measurements based on three different EDR estimation methods. The first two methods use the inertial dissipation method derived from Kolmogorov turbulence theory, and the third uses a maximum likelihood estimation assuming a von Kármán spectral model. Reasonable agreement was obtained between the three methods with various fluctuations, including diurnal variations for all seasons, while the EDR calculated from the third method displayed slightly higher EDR values than the other two methods. The result of the analysis showed that the mean (standard deviations) of logarithms of EDR had larger values as height decreased (increased), and the means were higher in the unstable planetary boundary layer (PBL) than in the stable PBL for this heterogeneous location adjacent to the coastlines. The probability density functions (PDFs) of the EDRs showed that the distribution was well-represented by a lognormal distribution in both the stable and unstable PBL, although the PDFs at the lowest level (2.5 m) deviated from those at other levels due to surface effects. Seasonal variations in the PDFs showed that there was less difference in the shape of the PDFs depending on atmospheric stability in the wintertime. Finally, we calculate the 1-yr statistics of the observed EDR, which will be used for future LLT forecast systems in Korea.

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Effect of Wind Transport of Turbulent Inhomogeneities on Estimation of the Turbulence Energy Dissipation Rate from Measurements by a Conically Scanning Coherent Doppler Lidar

Remote Sensing ◽

10.3390/rs12172802 ◽

2020 ◽

Vol 12 (17) ◽

pp. 2802

Author(s):

Igor N. Smalikho ◽

Viktor A. Banakh

Keyword(s):

Energy Dissipation ◽

Dissipation Rate ◽

Sonic Anemometer ◽

Scanning Speed ◽

Turbulent Energy ◽

Energy Dissipation Rate ◽

Stream Line ◽

Turbulence Energy ◽

Doppler Lidar ◽

Coherent Doppler Lidar

A method for estimation of the turbulent energy dissipation rate from measurements by a conically scanning pulsed coherent Doppler lidar (PCDL), with allowance for the wind transport of turbulent velocity fluctuations, has been developed. The method has been tested in comparative atmospheric experiments with a Stream Line PCDL (Halo Photonics, Brockamin, Worcester, United Kingdom) and a sonic anemometer. It has been demonstrated that the method provides unbiased estimates of the dissipation rate at arbitrarily large ratios of the mean wind velocity to the linear scanning speed.

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Review of 'Estimation of turbulence dissipation rate and its variability from sonic anemometer and wind Doppler lidar during the XPIA field campaign' by Bodini et al

10.5194/amt-2018-80-rc1 ◽

2018 ◽

Author(s):

Anonymous

Keyword(s):

Dissipation Rate ◽

Sonic Anemometer ◽

Doppler Lidar ◽

Field Campaign

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Supplementary material to "Estimation of turbulence dissipation rate and its variability from sonic anemometer and wind Doppler lidar during the XPIA field campaign"

10.5194/amt-2018-80-supplement ◽

2018 ◽

Author(s):

Nicola Bodini ◽

Julie K. Lundquist ◽

Rob K. Newsom

Keyword(s):

Dissipation Rate ◽

Sonic Anemometer ◽

Doppler Lidar ◽

Field Campaign ◽

Supplementary Material

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Wind Stress Over Waves: Effects of Sea Roughness and Atmospheric Stability

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.1488933 ◽

2002 ◽

Vol 124 (3) ◽

pp. 169-172 ◽

Cited By ~ 2

Author(s):

Dag Myrhaug ◽

Olav H. Slaattelid

Keyword(s):

Boundary Layer ◽

Wind Stress ◽

Local Equilibrium ◽

Surface Wind ◽

Atmospheric Stability ◽

Sea Surface ◽

Stability Function ◽

Sea Surface Wind ◽

Surface Wind Stress ◽

Sea Surface Roughness

The paper considers the effects of sea roughness and atmospheric stability on the sea surface wind stress over waves, which are in local equilibrium with the wind, by using the logarithmic boundary layer profile including a stability function, as well as adopting some commonly used sea surface roughness formulations. The engineering relevance of the results is also discussed.

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A Review of Progress and Applications of Pulsed Doppler Wind LiDARs

Remote Sensing ◽

10.3390/rs11212522 ◽

2019 ◽

Vol 11 (21) ◽

pp. 2522 ◽

Cited By ~ 4

Author(s):

Zhengliang Liu ◽

Janet F. Barlow ◽

Pak-Wai Chan ◽

Jimmy Chi Hung Fung ◽

Yuguo Li ◽

...

Keyword(s):

Wind Energy ◽

Numerical Models ◽

Real Life ◽

Doppler Lidar ◽

Promising Alternative ◽

3 Dimensional ◽

In Situ Techniques ◽

Energy Assessment ◽

Wind Shears ◽

Wind Profiles

Doppler wind LiDAR (Light Detection And Ranging) makes use of the principle of optical Doppler shift between the reference and backscattered radiations to measure radial velocities at distances up to several kilometers above the ground. Such instruments promise some advantages, including its large scan volume, movability and provision of 3-dimensional wind measurements, as well as its relatively higher temporal and spatial resolution comparing with other measurement devices. In recent decades, Doppler LiDARs developed by scientific institutes and commercial companies have been well adopted in several real-life applications. Doppler LiDARs are installed in about a dozen airports to study aircraft-induced vortices and detect wind shears. In the wind energy industry, the Doppler LiDAR technique provides a promising alternative to in-situ techniques in wind energy assessment, turbine wake analysis and turbine control. Doppler LiDARs have also been applied in meteorological studies, such as observing boundary layers and tracking tropical cyclones. These applications demonstrate the capability of Doppler LiDARs for measuring backscatter coefficients and wind profiles. In addition, Doppler LiDAR measurements show considerable potential for validating and improving numerical models. It is expected that future development of the Doppler LiDAR technique and data processing algorithms will provide accurate measurements with high spatial and temporal resolutions under different environmental conditions.

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