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

2018 ◽  
Author(s):  
Anonymous
Keyword(s):  
Dissipation Rate ◽  
Sonic Anemometer ◽  
Doppler Lidar ◽  
Field Campaign

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

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.

Turbulence Dissipation Rate in the Atmospheric Boundary Layer: Observations and WRF Mesoscale Modeling during the XPIA Field Campaign

2018 ◽  
Vol 146 (1) ◽  
pp. 351-371 ◽  
Author(s):  
Domingo Muñoz-Esparza ◽  
Robert D. Sharman ◽  
Julie K. Lundquist
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Planetary Boundary Layer ◽  
Dissipation Rate ◽  
Vertical Structure ◽  
Sonic Anemometer ◽  
Wrf Model ◽  
Order Structure ◽  
Field Campaign ◽  
Statistical Behavior

Abstract A better understanding and prediction of turbulence dissipation rate ε in the atmospheric boundary layer (ABL) is important for many applications. Herein, sonic anemometer data from the Experimental Planetary boundary layer Instrumentation Assessment (XPIA) field campaign (March–May 2015) are used to derive energy dissipation rate (EDR; =) within the first 300 m above the ground employing second-order structure functions. Turbulence dissipation rate is found to be strongly driven by the diurnal evolution of the ABL, presenting a distinct statistical behavior between daytime and nighttime conditions that follows log–Weibull and lognormal distributions, respectively. In addition, the vertical structure of EDR is characterized by a decrease with height above the surface, with the largest gradients occurring within the surface layer (z < 50 m). Convection-permitting mesoscale simulations were carried out with all of the 1.5-order turbulent kinetic energy (TKE) closure planetary boundary layer (PBL) schemes available in the Weather Research and Forecasting (WRF) Model. Overall, the three PBL schemes capture the observed diurnal evolution of EDR as well as the statistical behavior and vertical structure. However, the Mellor–Yamada-type schemes underestimate the large EDR levels during the bulk of daytime conditions, with the quasi-normal scale elimination (QNSE) scheme providing the best agreement with observations. During stably stratified nighttime conditions, Mellor–Yamada–Janjić (MYJ) and QNSE tend to exhibit an artificial “clipping” to their background TKE levels. A reduction in the model constant in the dissipation term for the Mellor–Yamada–Nakanishi–Niino (MYNN) scheme did not have a noticeable impact on EDR estimates. In contrast, application of a postprocessing statistical remapping technique reduced the systematic negative bias in the MYNN results by 75%.

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

2018 ◽  
Vol 11 (7) ◽  
pp. 4291-4308 ◽  
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 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.

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

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.

Evidence of Organized Large Eddies by Ground-Based Doppler Lidar, Sonic Anemometer and Sodar

1998 ◽  
Vol 88 (3) ◽  
pp. 343-361 ◽  
Author(s):  
Philippe Drobinski ◽  
Robert a. Brown ◽  
Pierre H. Flamant ◽  
Jacques Pelon
Keyword(s):  
Sonic Anemometer ◽  
Doppler Lidar ◽  
Large Eddies ◽  
Organized Large Eddies

scholarly journals A Method for Estimating the Turbulent Kinetic Energy Dissipation Rate from a Vertically Pointing Doppler Lidar, and Independent Evaluation from Balloon-Borne In Situ Measurements

2010 ◽  
Vol 27 (10) ◽  
pp. 1652-1664 ◽  
Author(s):  
Ewan J. O’Connor ◽  
Anthony J. Illingworth ◽  
Ian M. Brooks ◽  
Christopher D. Westbrook ◽  
Robin J. Hogan ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Convective Boundary Layer ◽  
Sonic Anemometer ◽  
Horizontal Wind ◽  
Inertial Subrange ◽  
Doppler Velocity ◽  
Doppler Lidar ◽  
Convective Boundary ◽  
Dissipation Rates

Abstract A method of estimating dissipation rates from a vertically pointing Doppler lidar with high temporal and spatial resolution has been evaluated by comparison with independent measurements derived from a balloon-borne sonic anemometer. This method utilizes the variance of the mean Doppler velocity from a number of sequential samples and requires an estimate of the horizontal wind speed. The noise contribution to the variance can be estimated from the observed signal-to-noise ratio and removed where appropriate. The relative size of the noise variance to the observed variance provides a measure of the confidence in the retrieval. Comparison with in situ dissipation rates derived from the balloon-borne sonic anemometer reveal that this particular Doppler lidar is capable of retrieving dissipation rates over a range of at least three orders of magnitude. This method is most suitable for retrieval of dissipation rates within the convective well-mixed boundary layer where the scales of motion that the Doppler lidar probes remain well within the inertial subrange. Caution must be applied when estimating dissipation rates in more quiescent conditions. For the particular Doppler lidar described here, the selection of suitably short integration times will permit this method to be applicable in such situations but at the expense of accuracy in the Doppler velocity estimates. The two case studies presented here suggest that, with profiles every 4 s, reliable estimates of ε can be derived to within at least an order of magnitude throughout almost all of the lowest 2 km and, in the convective boundary layer, to within 50%. Increasing the integration time for individual profiles to 30 s can improve the accuracy substantially but potentially confines retrievals to within the convective boundary layer. Therefore, optimization of certain instrument parameters may be required for specific implementations.

scholarly journals Overview and first results of the Wind and Storms Experiment (WASTEX): a field campaign to observe the formation of gusts using a Doppler lidar

2018 ◽  
Vol 15 ◽  
pp. 91-97 ◽  
Author(s):  
Florian Pantillon ◽  
Andreas Wieser ◽  
Bianca Adler ◽  
Ulrich Corsmeier ◽  
Peter Knippertz
Keyword(s):  
Small Scale ◽  
Extratropical Cyclones ◽  
Doppler Lidar ◽  
Winter Storms ◽  
Field Campaign ◽  
Layer Structures ◽  
First Results ◽  
Strong Winds ◽  
Upper Rhine ◽  
Waste Deposit

Abstract. Wind gusts are responsible for most damages in winter storms over central Europe, but capturing their small scale and short duration is a challenge for both models and observations. This motivated the Wind and Storms Experiment (WASTEX) dedicated to investigate the formation of gusts during the passage of extratropical cyclones. The field campaign took place during the winter 2016–2017 on a former waste deposit located close to Karlsruhe in the Upper Rhine Valley in southwest Germany. Twelve extratropical cyclones were sampled during WASTEX with a Doppler lidar system performing vertical scans in the mean wind direction and complemented with a Doppler C-band radar and a 200 m instrumented tower. First results are provided here for the three most intense storms and include a potential sting jet, a unique direct observation of a convective gust and coherent boundary-layer structures of strong winds.

scholarly journals Evaluation of turbulence measurement techniques from a single Doppler lidar

2017 ◽  
Vol 10 (8) ◽  
pp. 3021-3039 ◽  
Author(s):  
Timothy A. Bonin ◽  
Aditya Choukulkar ◽  
W. Alan Brewer ◽  
Scott P. Sandberg ◽  
Ann M. Weickmann ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Kinetic Energy ◽  
Planetary Boundary Layer ◽  
Turbulence Intensity ◽  
Measurement Techniques ◽  
Sonic Anemometer ◽  
Shear Velocity ◽  
Turbulence Kinetic Energy ◽  
Doppler Lidar ◽  
Turbulence Measurement

Abstract. Measurements of turbulence are essential to understand and quantify the transport and dispersal of heat, moisture, momentum, and trace gases within the planetary boundary layer (PBL). Through the years, various techniques to measure turbulence using Doppler lidar observations have been proposed. However, the accuracy of these measurements has rarely been validated against trusted in situ instrumentation. Herein, data from the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) are used to verify Doppler lidar turbulence profiles through comparison with sonic anemometer measurements. For 17 days at the end of the experiment, a single scanning Doppler lidar continuously cycled through different turbulence measurement strategies: velocity–azimuth display (VAD), six-beam scans, and range–height indicators (RHIs) with a vertical stare.Measurements of turbulence kinetic energy (TKE), turbulence intensity, and stress velocity from these techniques are compared with sonic anemometer measurements at six heights on a 300 m tower. The six-beam technique is found to generally measure turbulence kinetic energy and turbulence intensity the most accurately at all heights (r2  ≈  0.78), showing little bias in its observations (slope of  ≈  0. 95). Turbulence measurements from the velocity–azimuth display method tended to be biased low near the surface, as large eddies were not captured by the scan. None of the methods evaluated were able to consistently accurately measure the shear velocity (r2 =  0.15–0.17). Each of the scanning strategies assessed had its own strengths and limitations that need to be considered when selecting the method used in future experiments.

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