Turbulence Detection in the Atmospheric Boundary Layer using Coherent Doppler Wind Lidar and Microwave Radiometer

Abstract. The refractive index structure constant (Cn2) is a key parameter in describing the influence of turbulence on laser transmission in the atmosphere. A new method for continuous Cn2 profiling with both high temporal and spatial resolution is proposed and demonstrated. Under the assumption of the Kolmogorov “2/3 law”, the Cn2 profile can be calculated by using the wind field and turbulent kinetic energy dissipation rate (TKEDR) measured by coherent Doppler wind lidar (CDWL) and other meteorological parameters derived from microwave radiometer (MWR). In the horizontal experiment, a comparison between the results from our new method and measurements made by a large aperture scintillometer (LAS) is conducted. Except for the period of stratification stabilizing, the correlation coefficient between them in the six-day observation is 0.8389, the mean error and standard deviation is 1.09 × 10−15 m−2/3 and 2.14 × 10−15 m−2/3, respectively. In the vertical direction, the continuous observation results of Cn2 and other turbulence parameter profiles in the atmospheric boundary layer (ABL) are retrieved. More details of the atmospheric turbulence can be found in the ABL owe to the high temporal and spatial resolution of MWR and CDWL (spatial resolution of 26 m, temporal resolution of 147 s).

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Long-term measurements of refractive index structure constant in atmospheric boundary layer

10.1117/12.974422 ◽

2012 ◽

Author(s):

Otakar Jicha ◽

Pavel Pechac ◽

Stanislav Zvanovec ◽

Martin Grabner ◽

Vaclav Kvicera

Keyword(s):

Boundary Layer ◽

Refractive Index ◽

Atmospheric Boundary Layer ◽

Structure Constant ◽

Index Structure

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Analysis of physicochemical characteristics in the atmospheric boundary layer over the North Plain China based on large tethered balloon and Doppler wind lidar

10.5194/egusphere-egu2020-2795 ◽

2020 ◽

Author(s):

Haijiong Sun ◽

Yu Shi ◽

Fei Hu ◽

Zhe Zhang ◽

Weichen Ding

Keyword(s):

Boundary Layer ◽

Atmospheric Boundary Layer ◽

Vertical Profile ◽

Layer Structure ◽

Physicochemical Characteristics ◽

Transport Processes ◽

Observation Data ◽

Tethered Balloon ◽

Wind Lidar ◽

Doppler Wind Lidar

Physicochemical characteristics of the atmospheric boundary layer over North Plain China during the comprehensive observation experiment from 10 to 21 December 2018 were investigated in this paper. The observation data are obtained from the large tethered balloon, Doppler wind lidar, ground-level instruments. The maximum concentration of PM2.5 exceeded 200 &#181;g m-3, and the ratio value of PM2.5/PM10 was basically around 0.4 (maximum has reached approximately 0.8) during the whole observation period, indicating that explosive growth of fine ode dominant aerosols during the winter heating season. The peak solar irradiance was slightly larger on the clean day, compared with the value during the pollution process. The correlation coefficient between the concentration of PM2.5 and CO was highest (0.725) among the gas pollutants, and the relationship between O3 and PM2.5 was basically negative correlated, not simple linear relationship. Three distinctly different vertical profile types of the PM2.5 were categorized according to the vertical changes based on the total 33 vertical profiles obtained by the tethered balloon. Type 1 was mainly observed in the daytime, accounted for nearly 51.5%, the PM2.5 concentration decreased nearly linearly as a function of height below approximate 600 m; Type 2 shows a sharp decreasing trend from the ground to about 200 m; Type 3 shows multi-layer structure of pollutants, some pollutants suspended aloft in upper air. The vertical profile of PM2.5 was closely related to the atmospheric vertical structure such as the wind, temperature and turbulent kinetic energy, caused by the diurnal variation of the boundary layer. Small wind layer and the weak turbulence activities contributed to the accumulation of pollutants. Vertical patterns of the concentration of PM2.5 were also greatly affected by the local ground emission sources and regional transport processes.

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Integrated System for Atmospheric Boundary Layer Height Estimation (ISABLE) using a ceilometer and microwave radiometer

Atmospheric Measurement Techniques ◽

10.5194/amt-13-6965-2020 ◽

2020 ◽

Vol 13 (12) ◽

pp. 6965-6987

Author(s):

Jae-Sik Min ◽

Moon-Soo Park ◽

Jung-Hoon Chae ◽

Minsoo Kang

Keyword(s):

Boundary Layer ◽

Atmospheric Boundary Layer ◽

Layer Structure ◽

Microwave Radiometer ◽

Accurate Determination ◽

Integrated System ◽

Lapse Rate ◽

High Temporal Resolution ◽

Near Surface ◽

Boundary Layer Structure

Abstract. Accurate boundary layer structure and height are critical in the analysis of the features of air pollutants and local circulation. Although surface-based remote sensing instruments provide a high temporal resolution of the boundary layer structure, there are numerous uncertainties in terms of the accurate determination of the atmospheric boundary layer heights (ABLHs). In this study, an algorithm for an integrated system for ABLH estimation (ISABLE) was developed and applied to the vertical profile data obtained using a ceilometer and a microwave radiometer in Seoul city, Korea. A maximum of 19 ABLHs were estimated via the conventional time-variance, gradient, wavelet, and clustering methods using the backscatter coefficient from the ceilometer. Meanwhile, several stable boundary layer heights were extracted through near-surface inversion and environmental lapse rate methods using the potential temperature from the microwave radiometer. The ISABLE algorithm can find an optimal ABLH from post-processing, such as k-means clustering and density-based spatial clustering of applications with noise (DBSCAN) techniques. It was found that the ABLH determined using ISABLE exhibited more significant correlation coefficients and smaller mean bias and root mean square error between the radiosonde-derived ABLHs than those obtained using the most conventional methods. Clear skies exhibited higher daytime ABLH than cloudy skies, and the daily maximum ABLH was recorded in summer because of the more intense radiation. The ABLHs estimated by ISABLE are expected to contribute to the parameterization of vertical diffusion in the atmospheric boundary layer.

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Joint retrievals of cloud and drizzle in marine boundary layer clouds using ground-based radar, lidar and zenith radiances

Atmospheric Measurement Techniques ◽

10.5194/amt-8-2663-2015 ◽

2015 ◽

Vol 8 (7) ◽

pp. 2663-2683 ◽

Cited By ~ 21

Author(s):

M. D. Fielding ◽

J. C. Chiu ◽

R. J. Hogan ◽

G. Feingold ◽

E. Eloranta ◽

...

Keyword(s):

Boundary Layer ◽

Marine Boundary Layer ◽

Microwave Radiometer ◽

Cloud Water ◽

Radar Reflectivity ◽

New Method ◽

Error Statistics ◽

Water Path ◽

Boundary Layer Clouds ◽

Cloud Water Path

Abstract. Active remote sensing of marine boundary-layer clouds is challenging as drizzle drops often dominate the observed radar reflectivity. We present a new method to simultaneously retrieve cloud and drizzle vertical profiles in drizzling boundary-layer clouds using surface-based observations of radar reflectivity, lidar attenuated backscatter, and zenith radiances under conditions when precipitation does not reach the surface. Specifically, the vertical structure of droplet size and water content of both cloud and drizzle is characterised throughout the cloud. An ensemble optimal estimation approach provides full error statistics given the uncertainty in the observations. To evaluate the new method, we first perform retrievals using synthetic measurements from large-eddy simulation snapshots of cumulus under stratocumulus, where cloud water path is retrieved with an error of 31 g m−2. The method also performs well in non-drizzling clouds where no assumption of the cloud profile is required. We then apply the method to observations of marine stratocumulus obtained during the Atmospheric Radiation Measurement MAGIC deployment in the Northeast Pacific. Here, retrieved cloud water path agrees well with independent three-channel microwave radiometer retrievals, with a root mean square difference of 10–20 g m−2.

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Estimating local seeing at Observatorio Astronómico Nacional in San Pedro Mártir using CFD simulations of the atmospheric boundary layer

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1910 ◽

2020 ◽

Vol 496 (4) ◽

pp. 5552-5563

Author(s):

R Sánchez García ◽

M G Richer ◽

R Gómez Martínez ◽

R Avila

Keyword(s):

Boundary Layer ◽

Wind Speed ◽

Atmospheric Boundary Layer ◽

Vertical Profile ◽

Structure Constant ◽

Index Of Refraction ◽

San Pedro ◽

Computational Fluid Dynamics Simulations ◽

Dynamics Simulations ◽

Sierra San Pedro Martir

ABSTRACT We present computational fluid dynamics simulations of the atmospheric boundary layer (ABL) at the Observatorio Astronómico Nacional in the Sierra San Pedro Mártir (OAN-SPM) whose objective is to model the seeing observed at the site. We constrain the simulations using observations of the seeing, the vertical profile of the wind speed, and the vertical profile of the temperature, the first two resolved as a function of wind direction. We successfully model the seeing observed under typical wind conditions for each direction by adopting input profiles of the wind speed, the turbulent kinetic energy, and the energy dissipation. The resulting vertical profiles of the index of refraction structure constant are qualitatively similar to the mean profile derived from studies at the site.

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Review of Integrated System for Atmospheric Boundary Layer Height Estimation (ISABLE) using a Ceilometer and Microwave Radiometer. By Min et al.

10.5194/amt-2020-18-rc1 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Boundary Layer ◽

Atmospheric Boundary Layer ◽

Microwave Radiometer ◽

Integrated System ◽

Height Estimation ◽

Layer Height ◽

Boundary Layer Height ◽

Atmospheric Boundary Layer Height

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Review of Integrated System for Atmospheric Boundary Layer Height Estimation (ISABLE) using a Ceilometer and Microwave Radiometer. By Min et al.

10.5194/amt-2020-18-rc2 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Boundary Layer ◽

Atmospheric Boundary Layer ◽

Microwave Radiometer ◽

Integrated System ◽

Height Estimation ◽

Layer Height ◽

Boundary Layer Height ◽

Atmospheric Boundary Layer Height

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Planetary Boundary Layer Height Estimation from Doppler Wind Lidar Measurements, Radiosonde and Hysplit Model Comparison

Optica Pura y Aplicada ◽

10.7149/opa.48.3.179 ◽

2015 ◽

Vol 48 (3) ◽

pp. 179-183 ◽

Cited By ~ 3

Author(s):

G. de A. Moreira ◽

M. T. A. Marques ◽

W. Nakaema ◽

A.C. de C. A. Moreira ◽

E. Landulfo

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Model Comparison ◽

Planetary Boundary Layer Height ◽

Hysplit Model ◽

Layer Height ◽

Boundary Layer Height ◽

Lidar Measurements ◽

Wind Lidar ◽

Doppler Wind Lidar

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The COTUR project: Remote sensing of offshore turbulence for wind energy application

10.5194/amt-2020-511 ◽

2021 ◽

Author(s):

Etienne Cheynet ◽

Martin Flügge ◽

Joachim Reuder ◽

Jasna B. Jakobsen ◽

Yngve Heggelund ◽

...

Keyword(s):

Remote Sensing ◽

Boundary Layer ◽

Surface Layer ◽

Atmospheric Boundary Layer ◽

Wind Turbines ◽

Microwave Radiometer ◽

Wind Load ◽

Offshore Wind ◽

Offshore Wind Turbines ◽

Sensing Technology

Abstract. The paper presents the measurement strategy and dataset collected during the COTUR (COherence of TURbulence with lidars) campaign. This field experiment took place from February 2019 to April 2020 on the southwestern coast of Norway. The coherence quantifies the spatial correlation of eddies and is little known in the marine atmospheric boundary layer. The study was motivated by the need to better characterize the lateral coherence, which partly governs the dynamic wind load on multi-megawatt offshore wind turbines. During the COTUR campaign, the coherence was studied using land-based remote sensing technology. The instrument setup consisted of three long-range scanning Doppler wind lidars, one Doppler wind lidar profiler and one passive microwave radiometer. Both the WindScanner software and Lidar Planner software were used jointly to simultaneously orient the three scanner heads into the mean wind direction, which was provided by the lidar wind profiler. The radiometer instrument complemented these measurements by providing temperature and humidity profiles in the atmospheric boundary layer. The preliminary results show an undocumented variation of the lateral coherence with the distance from the coast. The scanning beams were pointed slightly upwards to record turbulence characteristics both within and above the surface layer, providing further insight on the applicability of surface-layer scaling to model the turbulent wind load on offshore wind turbines.

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