THE POSSIBILITY TO USE POLARIMETRIC RADAR FOR ATMOSPHERIC TURBULENCE INTENSITY ESTIMATE

Abstract. The energy observed in the surface layer, when using eddy-covariance techniques to measure turbulent fluxes, is not balanced. Important progress has been made in recent years in identifying potential reasons for this lack of closure in the energy balance, but the problem is not yet resolved. In this paper, long-term data that include output of tower, radiation, surface turbulence flux and soil measurement collected from September 2006 to August 2010 in the Semi-Arid Climate Change and Environment Observatory, Lanzhou University, in the semi-arid Loess Plateau of Northwest China, were analysed, focusing on the seasonal characteristics of the surface energy and the factors that have impact on the energy balance closure (EBC). The analysis shows that (1) the long-term observations are successful; the interaction between the land and the atmosphere in semi-arid climates can be represented by the turbulent transport of energy. In addition, even though the residual is obvious, this suggests that the factors that impact the EBC are stable, and their seasonal variations are identical. The analysis also shows that (2) four factors have obvious impact on the EBC: the diverse schemes for surface soil heat flux, the flux contribution from the target source area, the low-frequency part of the turbulence spectra, and the strength of atmospheric turbulence motion. The impact of these four factors on the EBC are similar in all seasons. Lastly, the results indicate that (3) atmospheric turbulence intensity is a very important factor in terms of its impact on the EBC. The relative turbulence intensity, RIw, characterises the strength of atmospheric turbulence motion, and is found to exert a noticeable impact on the EBC; in all seasons, the EBC is increased when the relative turbulence intensity is enlarged.

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Estimation of atmospheric turbulence intensity based on deep learning

10.1117/12.2603106 ◽

2021 ◽

Author(s):

Shengjie Ma ◽

Shiqia Hao ◽

Qingsong Zhao ◽

Chenlu Xu

Keyword(s):

Deep Learning ◽

Atmospheric Turbulence ◽

Turbulence Intensity

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Laboratory Measurements of the Influence of Turbulence Intensity on the Instantaneous-Fading Reciprocity of Bidirectional Atmospheric Laser Propagation Link

Applied Sciences ◽

10.3390/app11083499 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3499

Author(s):

Yi Liu ◽

Zhi Liu ◽

Yidi Chang ◽

Yang Liu ◽

Huilin Jiang

Keyword(s):

Correlation Coefficient ◽

Atmospheric Turbulence ◽

Turbulence Intensity ◽

Optical Signal ◽

Optical Channel ◽

Optical Signals ◽

Optical Channels ◽

Laser Propagation ◽

Hot Air ◽

Air Convection

The reciprocity of the atmospheric turbulence channel in the bidirectional atmospheric laser propagation link is experimentally tested. The bidirectional transceiving coaxial atmospheric laser propagation link is built by using a hot air convection-type atmospheric turbulence emulation device with adjustable turbulence intensity. The influence of different turbulence intensities on the instantaneous-fading correlation of channel is analyzed by the spot characteristics. When there is no atmospheric turbulence in the bidirectional transceiving coaxial atmospheric laser propagation link, the value of channel instantaneous fading correlation coefficient was merely 0.023, which indicates we did not find any reciprocity in the optical channel. With the increment in turbulence intensity, the channel instantaneous fading correlation coefficient presented a constant increasing trend and then tended to be stable around 0.9 in the end. At this moment, the similarity of the instantaneous change trends for these two receiving terminal optical signals, and the consistency of their probability density function, indicates that there is good reciprocity between the bidirectional atmospheric turbulence optical channels. With the increase in the optical signal scintillation factor, we can obtain the result where the correlation coefficient value decreases accordingly.

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Analysis on the Effects of Atmospheric Turbulence on Line-of-Sight Ultraviolet Communication System Performance

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1014.102 ◽

2014 ◽

Vol 1014 ◽

pp. 102-105

Author(s):

Yong Wang ◽

Meng Ying Su

Keyword(s):

Information Transmission ◽

Atmospheric Turbulence ◽

Turbulence Intensity ◽

Communication System ◽

Transmission Rate ◽

Optical Signals ◽

Communication System Performance ◽

Intensity Changes ◽

Ultraviolet Communication ◽

Ber Performance

In the ultraviolet communication system, optical signals being transmitted are not only attenuated in energy, but also affected by the atmospheric turbulence. The effects of atmospheric turbulence intensity and information transmission rate on the BER performance of UV communication system are analyzed and simulated in this paper. It can be found that when the atmospheric turbulence intensity changes from weak to strong, the BER performance deteriorates along, and under the certain atmospheric turbulence intensity, information transmission rate will also have an impact on the system BER performance, the information transmission rate becomes faster, the BER performance gets worse.

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Doppler Radar Measurements of Spatial Turbulence Intensity in the Atmospheric Boundary Layer

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-18-0151.1 ◽

2019 ◽

Vol 58 (7) ◽

pp. 1535-1555 ◽

Cited By ~ 3

Author(s):

James B. Duncan ◽

Brian D. Hirth ◽

John L. Schroeder

Keyword(s):

Boundary Layer ◽

Atmospheric Boundary Layer ◽

Atmospheric Turbulence ◽

Turbulence Intensity ◽

Large Scale ◽

Doppler Radar ◽

Atmospheric Stability ◽

Temporal Analysis ◽

Spatiotemporal Variability ◽

Complex Flow

AbstractRemote sensing instruments that scan have the ability to provide high-resolution spatial measurements of atmospheric boundary layer winds across a region. However, the time required to collect the volume of measurements used to produce this spatial representation of atmospheric winds typically limits the extraction of atmospheric turbulence information using traditional temporal analysis techniques. To overcome this constraint, a spatial turbulence intensity (STI) metric was developed to quantify atmospheric turbulence intensity (TI) through analysis of spatial wind field variability. The methods used to determine STI can be applied throughout the measurement domain to transform the spatially distributed velocity fields to analogous measurement maps of STI. This method enables a comprehensive spatial characterization of atmospheric TI. STI efficacy was examined across a range of wind speeds and atmospheric stability regimes using both single- and dual-Doppler measurements. STI demonstrated the ability to capture rapid fluctuations in TI and was able to discern large-scale TI trends consistent with the early evening transition. The ability to spatially depict atmospheric TI could benefit a variety of research disciplines such as the wind energy industry, where an understanding of wind plant complex flow spatiotemporal variability is limited.

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TURBULENCE INTENSITY ESTIMATE IN THE SUBCRITICAL REGIME OF LIQUID HYDROMETEOR REVERSE DEFORMATION

Proceedings of National Aviation University ◽

10.18372/2306-1472.50.112 ◽

2012 ◽

Vol 50 (1) ◽

Author(s):

Ю. Авер’янова ◽

А. Аверьянов

Keyword(s):

Turbulence Intensity ◽

Subcritical Regime ◽

Reverse Deformation ◽

Intensity Estimate

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Using Doppler lidar systems to detect atmospheric turbulence in Iceland

10.5194/amt-2019-3 ◽

2019 ◽

Author(s):

Shu Yang ◽

Guðrún Nína Petersen ◽

Sibylle von Löwis ◽

Jana Preißler ◽

David Christian Finger

Keyword(s):

Atmospheric Turbulence ◽

Wind Velocity ◽

Turbulence Intensity ◽

Weather Conditions ◽

Wind Fields ◽

Air Traffic Controllers ◽

Noise Filter ◽

Filter Methods ◽

Kolmogorov Theory ◽

Lidar Observations

Abstract. The temporal and spatial scale of atmospheric turbulence is very dynamic, requiring an adequate method to detect and monitor turbulence with high resolution. Doppler Light Detection and Ranging (lidar) systems have been used widely to observe and monitor wind velocity and atmospheric turbulence profiles. Lidar systems can provide continuous information about wind fields using the Doppler effect from emitted light signals. In this study, we use a Leosphere Windcube 200S lidar system stationed in Reykjavik, Iceland, to evaluate turbulence intensity by estimating eddy dissipation rate (EDR). For this purpose, we retrieved radial wind velocity observations from velocity azimuth display (VAD) scans to compute EDR based on the Kolmogorov theory. We compared different noise filter methods, scan strategies and calculation approaches during different selected weather conditions to assess the accuracy of our EDR estimations. The results reveal that the lidar observations can detect and quantify atmospheric turbulence with high spatial and temporal resolution, our algorithm can retrieve EDR and indicate the turbulence intensity. These results suggest that lidar observation can be of high importance for potential end-user, e.g. air traffic controllers at the local airport. The work is an important step towards enhanced aviation safety in a subpolar climate characterized by severe wind turbulence.

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Retrieving atmospheric turbulence information from regular commercial aircraft using Mode-S and ADS-B

Atmospheric Measurement Techniques ◽

10.5194/amt-9-2253-2016 ◽

2016 ◽

Vol 9 (5) ◽

pp. 2253-2265 ◽

Cited By ~ 5

Author(s):

Jacek M. Kopeć ◽

Kamil Kwiatkowski ◽

Siebren de Haan ◽

Szymon P. Malinowski

Keyword(s):

Atmospheric Turbulence ◽

Turbulence Intensity ◽

Dissipation Rate ◽

Vertical Acceleration ◽

Background Wind ◽

Commercial Aircraft ◽

Data Set ◽

Processing Methods ◽

Research Aircraft

Abstract. Navigational information broadcast by commercial aircraft in the form of Mode-S EHS (Mode-S Enhanced Surveillance) and ADS-B (Automatic Dependent Surveillance–Broadcast) messages can be considered a new source of upper tropospheric and lower stratospheric turbulence estimates. A set of three processing methods is proposed and analysed using a quality record of turbulence encounters made by a research aircraft.The proposed methods are based on processing the vertical acceleration or the background wind into the eddy dissipation rate. Turbulence intensity can be estimated using the standard content of the Mode-S EHS/ADS-B.The results are based on a Mode-S EHS/ADS-B data set generated synthetically based on the transmissions from the research aircraft. This data set was validated using the overlapping record of the Mode-S EHS/ADS-B received from the same research aircraft. The turbulence intensity, meaning the eddy dissipation rate, obtained from the proposed methods based on the Mode-S EHS/ADS-B is compared with the value obtained using on-board accelerometer. The results of the comparison indicate the potential of the methods. The advantages and limitation of the presented approaches are discussed.

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