Articles | Volume 12, issue 1
https://doi.org/10.5194/amt-12-237-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-12-237-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
15 Jan 2019
Research article |
| 15 Jan 2019
| 15 Jan 2019
A method to assess the accuracy of sonic anemometer measurements
DTU Wind Energy, Technical University of Denmark, Roskilde, Denmark
Ebba Dellwik
DTU Wind Energy, Technical University of Denmark, Roskilde, Denmark
Jakob Mann
DTU Wind Energy, Technical University of Denmark, Roskilde, Denmark
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Wind Energ. Sci., 3, 191–202, https://doi.org/10.5194/wes-3-191-2018, https://doi.org/10.5194/wes-3-191-2018, 2018
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Wind Energ. Sci., 2, 133–152, https://doi.org/10.5194/wes-2-133-2017, https://doi.org/10.5194/wes-2-133-2017, 2017
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Nacelle lidars are nowadays extensively used to scan the turbine inflow. Thus, it is important to characterize turbulence from their measurements. We present two methods to perform turbulence estimation and demonstrate them using two types of lidars. With one method we can estimate the along-wind unfiltered variance accurately. With the other we can estimate the filtered radial velocity variance accurately and velocity-tensor parameters under neutral and high wind-speed conditions.
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Wind Energ. Sci., 1, 101–114, https://doi.org/10.5194/wes-1-101-2016, https://doi.org/10.5194/wes-1-101-2016, 2016
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We have developed flow models from different complexities. Unfortunately, high quality and reliable wind observations affected by obstacles are rare and so we have few means to evaluate our models. We have therefore performed a campaign in which we measured the effect of a fence on the atmosphere using laser-based instruments. The effect can still be noticed as far as 11 fence heights. A wake theory seems to predict the obstacle effect when we are looking at distances beyond 6 fence heights.
Etienne Cheynet, Jan Markus Diezel, Hilde Haakenstad, Øyvind Breivik, Alfredo Peña, and Joachim Reuder
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2024-119, https://doi.org/10.5194/wes-2024-119, 2024
Preprint under review for WES
Short summary
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This study aims to help future large offshore wind turbines and airborne wind energy systems by providing insights into wind speeds at much higher altitudes than previously examined. We assessed three wind models (ERA5, NORA3, and NEWA) to predict wind speeds up to 500 m. Using lidar data from Norway and the North Sea, we found that ERA5 excels offshore, while NORA3 performs best onshore. However, the performance of the models depends on the locations and the evaluation criteria.
Alfredo Peña, Ginka Georgieva Yankova, and Vasiliki Mallini
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2024-108, https://doi.org/10.5194/wes-2024-108, 2024
Revised manuscript accepted for WES
Short summary
Short summary
Lidars are vastly used in wind energy but most users struggle when interpreting lidar turbulence measures. Here we explain why is difficult to convert them into standard measurements. We show two ways to convert lidar to in-situ turbulence measurements, both using neural networks with one of them based on physics while the other is purely data driven. They show promising results when compared to high-quality turbulence measurements from a tall mast.
Abdul Haseeb Syed and Jakob Mann
Wind Energ. Sci., 9, 1381–1391, https://doi.org/10.5194/wes-9-1381-2024, https://doi.org/10.5194/wes-9-1381-2024, 2024
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Wind flow consists of swirling patterns of air called eddies, some as big as many kilometers across, while others are as small as just a few meters. This paper introduces a method to simulate these large swirling patterns on a flat grid. Using these simulations we can better figure out how these large eddies affect big wind turbines in terms of loads and forces.
Liqin Jin, Mauro Ghirardelli, Jakob Mann, Mikael Sjöholm, Stephan Thomas Kral, and Joachim Reuder
Atmos. Meas. Tech., 17, 2721–2737, https://doi.org/10.5194/amt-17-2721-2024, https://doi.org/10.5194/amt-17-2721-2024, 2024
Short summary
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Three-dimensional wind fields can be accurately measured by sonic anemometers. However, the traditional mast-mounted sonic anemometers are not flexible in various applications, which can be potentially overcome by drones. Therefore, we conducted a proof-of-concept study by applying three continuous-wave Doppler lidars to characterize the complex flow around a drone to validate the results obtained by CFD simulations. Both methods show good agreement, with a velocity difference of 0.1 m s-1.
Isadora Coimbra, Jakob Mann, and José Palma
EGUsphere, https://doi.org/10.5194/egusphere-2024-936, https://doi.org/10.5194/egusphere-2024-936, 2024
Short summary
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Dual-lidar measurements are explored here as a cost-effective alternative for measuring the wind at great heights. From measurements at a mountainous site, we showed that this methodology can accurately capture mean wind speeds and turbulence under different flow conditions, and we recommended optimal lidar placement and sampling rates. This methodology allows the construction of vertical wind profiles up to 430 m, surpassing traditional meteorological mast heights and single lidar capabilities.
Oscar García-Santiago, Andrea N. Hahmann, Jake Badger, and Alfredo Peña
Wind Energ. Sci., 9, 963–979, https://doi.org/10.5194/wes-9-963-2024, https://doi.org/10.5194/wes-9-963-2024, 2024
Short summary
Short summary
This study compares the results of two wind farm parameterizations (WFPs) in the Weather Research and Forecasting model, simulating a two-turbine array under three atmospheric stabilities with large-eddy simulations. We show that the WFPs accurately depict wind speeds either near turbines or in the far-wake areas, but not both. The parameterizations’ performance varies by variable (wind speed or turbulent kinetic energy) and atmospheric stability, with reduced accuracy in stable conditions.
Wei Fu, Feng Guo, David Schlipf, and Alfredo Peña
Wind Energ. Sci., 8, 1893–1907, https://doi.org/10.5194/wes-8-1893-2023, https://doi.org/10.5194/wes-8-1893-2023, 2023
Short summary
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A high-quality preview of the rotor-effective wind speed is a key element of the benefits of feedforward pitch control. We model a one-beam lidar in the spinner of a 15 MW wind turbine. The lidar rotates with the wind turbine and scans the inflow in a circular pattern, mimicking a multiple-beam lidar at a lower cost. We found that a spinner-based one-beam lidar provides many more control benefits than the one on the nacelle, which is similar to a four-beam nacelle lidar for feedforward control.
Liqin Jin, Jakob Mann, Nikolas Angelou, and Mikael Sjöholm
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Short summary
By sampling the spectra from continuous-wave Doppler lidars very fast, the rain-induced Doppler signal can be suppressed and the bias in the wind velocity estimation can be reduced. The method normalizes 3 kHz spectra by their peak values before averaging them down to 50 Hz. Over 3 h, we observe a significant reduction in the bias of the lidar data relative to the reference sonic data when the largest lidar focus distance is used. The more it rains, the more the bias is reduced.
Alessandro Sebastiani, James Bleeg, and Alfredo Peña
Wind Energ. Sci., 8, 1795–1808, https://doi.org/10.5194/wes-8-1795-2023, https://doi.org/10.5194/wes-8-1795-2023, 2023
Short summary
Short summary
The power curve of a wind turbine indicates the turbine power output in relation to the wind speed. Therefore, power curves are critically important to estimate the production of future wind farms as well as to assess whether operating wind farms are functioning correctly. Since power curves are often measured in wind farms, they might be affected by the interactions between the turbines. We show that these effects are not negligible and present a method to correct for them.
Nikolas Angelou, Jakob Mann, and Camille Dubreuil-Boisclair
Wind Energ. Sci., 8, 1511–1531, https://doi.org/10.5194/wes-8-1511-2023, https://doi.org/10.5194/wes-8-1511-2023, 2023
Short summary
Short summary
This study presents the first experimental investigation using two nacelle-mounted wind lidars that reveal the upwind and downwind conditions relative to a full-scale floating wind turbine. We find that in the case of floating wind turbines with small pitch and roll oscillating motions (< 1°), the ambient turbulence is the main driving factor that determines the propagation of the wake characteristics.
Maarten Paul van der Laan, Oscar García-Santiago, Mark Kelly, Alexander Meyer Forsting, Camille Dubreuil-Boisclair, Knut Sponheim Seim, Marc Imberger, Alfredo Peña, Niels Nørmark Sørensen, and Pierre-Elouan Réthoré
Wind Energ. Sci., 8, 819–848, https://doi.org/10.5194/wes-8-819-2023, https://doi.org/10.5194/wes-8-819-2023, 2023
Short summary
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Offshore wind farms are more commonly installed in wind farm clusters, where wind farm interaction can lead to energy losses. In this work, an efficient numerical method is presented that can be used to estimate these energy losses. The novel method is verified with higher-fidelity numerical models and validated with measurements of an existing wind farm cluster.
Wei Fu, Alessandro Sebastiani, Alfredo Peña, and Jakob Mann
Wind Energ. Sci., 8, 677–690, https://doi.org/10.5194/wes-8-677-2023, https://doi.org/10.5194/wes-8-677-2023, 2023
Short summary
Short summary
Nacelle lidars with different beam scanning locations and two types of systems are considered for inflow turbulence estimations using both numerical simulations and field measurements. The turbulence estimates from a sonic anemometer at the hub height of a Vestas V52 turbine are used as references. The turbulence parameters are retrieved using the radial variances and a least-squares procedure. The findings from numerical simulations have been verified by the analysis of the field measurements.
Abdul Haseeb Syed, Jakob Mann, Andreas Platis, and Jens Bange
Wind Energ. Sci., 8, 125–139, https://doi.org/10.5194/wes-8-125-2023, https://doi.org/10.5194/wes-8-125-2023, 2023
Short summary
Short summary
Wind turbines extract energy from the incoming wind flow, which needs to be recovered. In very large offshore wind farms, the energy is recovered mostly from above the wind farm in a process called entrainment. In this study, we analyzed the effect of atmospheric stability on the entrainment process in large offshore wind farms using measurements recorded by a research aircraft. This is the first time that in situ measurements are used to study the energy recovery process above wind farms.
Andrea N. Hahmann, Oscar García-Santiago, and Alfredo Peña
Wind Energ. Sci., 7, 2373–2391, https://doi.org/10.5194/wes-7-2373-2022, https://doi.org/10.5194/wes-7-2373-2022, 2022
Short summary
Short summary
We explore the changes in wind energy resources in northern Europe using output from simulations from the Climate Model Intercomparison Project (CMIP6) under the high-emission scenario. Our results show that climate change does not particularly alter annual energy production in the North Sea but could affect the seasonal distribution of these resources, significantly reducing energy production during the summer from 2031 to 2050.
Felix Kelberlau and Jakob Mann
Atmos. Meas. Tech., 15, 5323–5341, https://doi.org/10.5194/amt-15-5323-2022, https://doi.org/10.5194/amt-15-5323-2022, 2022
Short summary
Short summary
Floating lidar systems are used for measuring wind speeds offshore, and their motion influences the measurements. This study describes the motion-induced bias on mean wind speed estimates by simulating the lidar sampling pattern of a moving lidar. An analytic model is used to validate the simulations. The bias is low and depends on amplitude and frequency of motion as well as on wind shear. It has been estimated for the example of the Fugro SEAWATCH wind lidar buoy carrying a ZX 300M lidar.
Alessandro Sebastiani, Alfredo Peña, Niels Troldborg, and Alexander Meyer Forsting
Wind Energ. Sci., 7, 875–886, https://doi.org/10.5194/wes-7-875-2022, https://doi.org/10.5194/wes-7-875-2022, 2022
Short summary
Short summary
The power performance of a wind turbine is often tested with the turbine standing in a row of several wind turbines, as it is assumed that the performance is not affected by the neighbouring turbines. We test this assumption with both simulations and measurements, and we show that the power performance can be either enhanced or lowered by the neighbouring wind turbines. Consequently, we also show how power performance testing might be biased when performed on a row of several wind turbines.
Wei Fu, Alfredo Peña, and Jakob Mann
Wind Energ. Sci., 7, 831–848, https://doi.org/10.5194/wes-7-831-2022, https://doi.org/10.5194/wes-7-831-2022, 2022
Short summary
Short summary
Measuring the variability of the wind is essential to operate the wind turbines safely. Lidars of different configurations have been placed on the turbines’ nacelle to measure the inflow remotely. This work found that the multiple-beam lidar is the only one out of the three employed nacelle lidars that can give detailed information about the inflow variability. The other two commercial lidars, which have two and four beams, respectively, measure only the fluctuation in the along-wind direction.
Nikolas Angelou, Jakob Mann, and Ebba Dellwik
Atmos. Chem. Phys., 22, 2255–2268, https://doi.org/10.5194/acp-22-2255-2022, https://doi.org/10.5194/acp-22-2255-2022, 2022
Short summary
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In this study we use state-of-the-art scanning wind lidars to investigate the wind field in the near-wake region of a mature, open-grown tree. Our measurements provide for the first time a picture of the mean and the turbulent spatial fluctuations in the flow in the wake of a tree in its natural environment. Our observations support the hypothesis that even simple models can realistically simulate the turbulent fluctuations in the wake and thus predict the effect of trees in flow models.
Davide Conti, Nikolay Dimitrov, Alfredo Peña, and Thomas Herges
Wind Energ. Sci., 6, 1117–1142, https://doi.org/10.5194/wes-6-1117-2021, https://doi.org/10.5194/wes-6-1117-2021, 2021
Short summary
Short summary
We carry out a probabilistic calibration of the Dynamic Wake Meandering (DWM) model using high-spatial- and high-temporal-resolution nacelle-based lidar measurements of the wake flow field. The experimental data were collected from the Scaled Wind Farm Technology (SWiFT) facility in Texas. The analysis includes the velocity deficit, wake-added turbulence, and wake meandering features under various inflow wind and atmospheric-stability conditions.
Toby D. Jackson, Sarab Sethi, Ebba Dellwik, Nikolas Angelou, Amanda Bunce, Tim van Emmerik, Marine Duperat, Jean-Claude Ruel, Axel Wellpott, Skip Van Bloem, Alexis Achim, Brian Kane, Dominick M. Ciruzzi, Steven P. Loheide II, Ken James, Daniel Burcham, John Moore, Dirk Schindler, Sven Kolbe, Kilian Wiegmann, Mark Rudnicki, Victor J. Lieffers, John Selker, Andrew V. Gougherty, Tim Newson, Andrew Koeser, Jason Miesbauer, Roger Samelson, Jim Wagner, Anthony R. Ambrose, Andreas Detter, Steffen Rust, David Coomes, and Barry Gardiner
Biogeosciences, 18, 4059–4072, https://doi.org/10.5194/bg-18-4059-2021, https://doi.org/10.5194/bg-18-4059-2021, 2021
Short summary
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We have all seen trees swaying in the wind, but did you know that this motion can teach us about ecology? We summarized tree motion data from many different studies and looked for similarities between trees. We found that the motion of trees in conifer forests is quite similar to each other, whereas open-grown trees and broadleaf forests show more variation. It has been suggested that additional damping or amplification of tree motion occurs at high wind speeds, but we found no evidence of this.
Davide Conti, Vasilis Pettas, Nikolay Dimitrov, and Alfredo Peña
Wind Energ. Sci., 6, 841–866, https://doi.org/10.5194/wes-6-841-2021, https://doi.org/10.5194/wes-6-841-2021, 2021
Short summary
Short summary
We define two lidar-based procedures for improving the accuracy of wind turbine load assessment under wake conditions. The first approach incorporates lidar observations directly into turbulence fields serving as inputs for aeroelastic simulations; the second approach imposes lidar-fitted wake deficit time series on the turbulence fields. The uncertainty in the lidar-based power and load predictions is quantified for a variety of scanning configurations and atmosphere turbulence conditions.
Alfredo Peña, Branko Kosović, and Jeffrey D. Mirocha
Wind Energ. Sci., 6, 645–661, https://doi.org/10.5194/wes-6-645-2021, https://doi.org/10.5194/wes-6-645-2021, 2021
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We investigate the ability of a community-open weather model to simulate the turbulent atmosphere by comparison with measurements from a 250 m mast at a flat site in Denmark. We found that within three main atmospheric stability regimes, idealized simulations reproduce closely the characteristics of the observations with regards to the mean wind, direction, turbulent fluxes, and turbulence spectra. Our work provides foundation for the use of the weather model in multiscale real-time simulations.
Pedro Santos, Jakob Mann, Nikola Vasiljević, Elena Cantero, Javier Sanz Rodrigo, Fernando Borbón, Daniel Martínez-Villagrasa, Belén Martí, and Joan Cuxart
Wind Energ. Sci., 5, 1793–1810, https://doi.org/10.5194/wes-5-1793-2020, https://doi.org/10.5194/wes-5-1793-2020, 2020
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This study presents results from the Alaiz experiment (ALEX17), featuring the characterization of two cases with flow features ranging from 0.1 to 10 km in complex terrain. We show that multiple scanning lidars can capture in detail a type of atmospheric wave that can happen up to 10 % of the time at this site. The results are in agreement with multiple ground observations and demonstrate the role of atmospheric stability in flow phenomena that need to be better captured by numerical models.
Johan Arnqvist, Julia Freier, and Ebba Dellwik
Biogeosciences, 17, 5939–5952, https://doi.org/10.5194/bg-17-5939-2020, https://doi.org/10.5194/bg-17-5939-2020, 2020
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Data generated by airborne laser scans enable the characterization of surface vegetation for any application that might need it, such as forest management, modeling for numerical weather prediction, or wind energy estimation. In this work we present a new algorithm for calculating the vegetation density using data from airborne laser scans. The new routine is more robust than earlier methods, and an implementation in popular programming languages accompanies the article to support new users.
Martin Dörenkämper, Bjarke T. Olsen, Björn Witha, Andrea N. Hahmann, Neil N. Davis, Jordi Barcons, Yasemin Ezber, Elena García-Bustamante, J. Fidel González-Rouco, Jorge Navarro, Mariano Sastre-Marugán, Tija Sīle, Wilke Trei, Mark Žagar, Jake Badger, Julia Gottschall, Javier Sanz Rodrigo, and Jakob Mann
Geosci. Model Dev., 13, 5079–5102, https://doi.org/10.5194/gmd-13-5079-2020, https://doi.org/10.5194/gmd-13-5079-2020, 2020
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This is the second of two papers that document the creation of the New European Wind Atlas (NEWA). The paper includes a detailed description of the technical and practical aspects that went into running the mesoscale simulations and the microscale downscaling for generating the climatology. A comprehensive evaluation of each component of the NEWA model chain is presented using observations from a large set of tall masts located all over Europe.
Pedro Santos, Alfredo Peña, and Jakob Mann
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-960, https://doi.org/10.5194/acp-2020-960, 2020
Preprint withdrawn
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We show that the vector of vertical flux of horizontal momentum and the vector of the mean vertical gradient of horizontal velocity are not aligned, based on Doppler wind lidar observations up to 500 m, both offshore and onshore. We illustrate that a mesoscale model output matches the observed mean wind speed and momentum fluxes well, but that this model output as well as idealized large-eddy simulations have deviations with the observations when looking at the turning of the wind.
Davide Conti, Nikolay Dimitrov, and Alfredo Peña
Wind Energ. Sci., 5, 1129–1154, https://doi.org/10.5194/wes-5-1129-2020, https://doi.org/10.5194/wes-5-1129-2020, 2020
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We propose a method for carrying out wind turbine load validation in wake conditions using measurements from forward-looking nacelle lidars. The uncertainty of aeroelastic load predictions is quantified against wind turbine on-board sensor data. This work demonstrates the applicability of nacelle-mounted lidar measurements to extend load and power validations under wake conditions and highlights the main challenges.
Robert Menke, Nikola Vasiljević, Johannes Wagner, Steven P. Oncley, and Jakob Mann
Wind Energ. Sci., 5, 1059–1073, https://doi.org/10.5194/wes-5-1059-2020, https://doi.org/10.5194/wes-5-1059-2020, 2020
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The estimation of wind resources in complex terrain is challenging as the wind conditions change significantly over short distances, different to flat terrain, where spatial changes are small. We demonstrate in this work that wind lidars can remotely map wind resources over large areas. This will have implications for the planning of wind energy projects and ultimately reduce uncertainties in wind resource estimations in complex terrain, making such areas more interesting for future development.
Andrey Sogachev, Dalibor Cavar, Mark Kelly, Ebba Dellwik, Tobias Klaas, and Paul Kühn
Adv. Sci. Res., 17, 53–61, https://doi.org/10.5194/asr-17-53-2020, https://doi.org/10.5194/asr-17-53-2020, 2020
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Recently an objective method was suggested to translate realistic vegetation characteristics into spatially varying values of effective roughness. This parameter allows prediction of wind flow over vegetation using models, without incorporating local drag forces in each grid volume of a three-dimensional model domain. Results of the flow simulations over different forested sites show that an approach based on a roughness representation of forest is appropriate only for the flat terrain.
Felix Kelberlau and Jakob Mann
Wind Energ. Sci., 5, 519–541, https://doi.org/10.5194/wes-5-519-2020, https://doi.org/10.5194/wes-5-519-2020, 2020
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Wind speeds can be measured remotely from the ground with lidars. Their estimates are accurate for mean speeds, but turbulence leads to measurement errors. We predict these errors using computer-generated data and compare lidar measurements with data from a meteorological mast. The comparison shows that deviations depend on wind direction, measurement height, and wind conditions. Our method to reduce the measurement error is successful when the wind is aligned with one of the lidar beams.
Jonas Kazda and Jakob Mann
Wind Energ. Sci., 5, 439–450, https://doi.org/10.5194/wes-5-439-2020, https://doi.org/10.5194/wes-5-439-2020, 2020
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This work presents the first analytical solution for the quantification of the spatial variance of the second-order moment of correlated wind speeds. The spatial variance is defined as random differences in the sample variance of wind speed between different points in space. The approach is successfully verified using simulation and field data. The impact of the spatial variance on wind farm control, the verification of wind turbine performance and sensor verification are then investigated.
Charlotte B. Hasager, Andrea N. Hahmann, Tobias Ahsbahs, Ioanna Karagali, Tija Sile, Merete Badger, and Jakob Mann
Wind Energ. Sci., 5, 375–390, https://doi.org/10.5194/wes-5-375-2020, https://doi.org/10.5194/wes-5-375-2020, 2020
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Europe's offshore wind resource mapping is part of the New European Wind Atlas (NEWA) international consortium effort. This study presents the results of analysis of synthetic aperture radar (SAR) ocean wind maps based on Envisat and Sentinel-1 with a brief description of the wind retrieval process and Advanced Scatterometer (ASCAT) ocean wind maps. Furthermore, the Weather Research and Forecasting (WRF) offshore wind atlas of NEWA is presented.
Maarten Paul van der Laan, Mark Kelly, Rogier Floors, and Alfredo Peña
Wind Energ. Sci., 5, 355–374, https://doi.org/10.5194/wes-5-355-2020, https://doi.org/10.5194/wes-5-355-2020, 2020
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The design of wind turbines and wind farms can be improved by increasing the accuracy of the inflow models representing the atmospheric boundary layer (ABL). In this work we employ numerical simulations of the idealized ABL, which can represent the mean effects of Coriolis and buoyancy forces and surface roughness. We find a new model-based similarity that provides a better understanding of the idealized ABL. In addition, we extend the model to include effects of convective buoyancy forces.
Dominique P. Held and Jakob Mann
Wind Energ. Sci., 4, 421–438, https://doi.org/10.5194/wes-4-421-2019, https://doi.org/10.5194/wes-4-421-2019, 2019
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In this study a model of the coherence between turbine- and lidar-estimated rotor-effective wind speed (REWS) is presented. The model is compared against experimental data from two field tests using two- and four-beam nacelle-mounted lidar systems on a test turbine. The proposed model agrees better with the field data than previously used models. Also, it was shown that the advection speed can be estimated by the REWS measured by the lidar.
Dominique P. Held and Jakob Mann
Wind Energ. Sci., 4, 407–420, https://doi.org/10.5194/wes-4-407-2019, https://doi.org/10.5194/wes-4-407-2019, 2019
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In this study the capabilities of detecting wakes in the inflow of turbines by nacelle-mounted lidars are investigated. It is shown that higher turbulence levels can be measured within a wake by estimating the Doppler spectrum width. In an experimental setup all half- and full-wake situations have been identified. A correction method for the influence of the wake on the lidar system has also been proposed..
Felix Kelberlau and Jakob Mann
Atmos. Meas. Tech., 12, 1871–1888, https://doi.org/10.5194/amt-12-1871-2019, https://doi.org/10.5194/amt-12-1871-2019, 2019
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Lidars are devices that can measure wind velocities remotely from the ground. Their estimates are very accurate in the mean but wind speed fluctuations lead to measurement errors. The presented data processing methods mitigate several of the error causes: first, by making use of knowledge about the mean wind direction and, second, by determining the location of air packages and sensing them in the best moment. Both methods can be applied to existing wind lidars and results are very promising.
Robert Menke, Nikola Vasiljević, Jakob Mann, and Julie K. Lundquist
Atmos. Chem. Phys., 19, 2713–2723, https://doi.org/10.5194/acp-19-2713-2019, https://doi.org/10.5194/acp-19-2713-2019, 2019
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This research utilizes several months of lidar measurements from the Perdigão 2017 campaign to investigate flow recirculation zones that occur at the two parallel ridges at the measurement site in Portugal. We found that recirculation occurs in over 50 % of the time when the wind direction is perpendicular to the direction of the ridges. Moreover, we show three-dimensional changes of the zones along the ridges and the implications of recirculation on wind turbines that are operating downstream.
Dominique P. Held and Jakob Mann
Atmos. Meas. Tech., 11, 6339–6350, https://doi.org/10.5194/amt-11-6339-2018, https://doi.org/10.5194/amt-11-6339-2018, 2018
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In this paper we study the effect of different methods to derive the radial wind speed from a lidar Doppler spectrum. Numerical simulations and experimental results both indicate that the median method has slight improvements over the centroid method in terms of turbulent attenuation and also showed the lowest root mean squared error. Thus, when the aim is to reduce the volume averaging effect and obtain time series with a high temporal resolution, we recommend using the median method.
Robert Menke, Nikola Vasiljević, Kurt S. Hansen, Andrea N. Hahmann, and Jakob Mann
Wind Energ. Sci., 3, 681–691, https://doi.org/10.5194/wes-3-681-2018, https://doi.org/10.5194/wes-3-681-2018, 2018
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This study investigates the behaviour of wind turbine wakes in complex terrain. Using six scanning lidars, we measured the wake of a single turbine at the Perdigão site in Portugal in 2015. Our findings show that wake propagation is highly dependent on the atmospheric stability, which is mostly ignored in flow simulation used for wind farm layout design. The wake is lifted up during unstable atmospheric conditions and follows the terrain downwards during stable conditions.
Rogier Floors, Peter Enevoldsen, Neil Davis, Johan Arnqvist, and Ebba Dellwik
Wind Energ. Sci., 3, 353–370, https://doi.org/10.5194/wes-3-353-2018, https://doi.org/10.5194/wes-3-353-2018, 2018
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Applying erroneous boundary conditions (surface roughness) for wind flow modelling can have a large impact on the estimated performance of wind turbines, particularly in forested areas. Traditionally the estimation of the surface roughness is based on a subjective process that requires assigning a value to each land use class in the vicinity of the wind farm. Here we propose a new method which converts lidar scans from a plane into maps that can be used for wind flow modelling.
Laura Valldecabres, Alfredo Peña, Michael Courtney, Lueder von Bremen, and Martin Kühn
Wind Energ. Sci., 3, 313–327, https://doi.org/10.5194/wes-3-313-2018, https://doi.org/10.5194/wes-3-313-2018, 2018
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This paper focuses on the use of scanning lidars for very short-term forecasting of wind speeds in a near-coastal area. An extensive data set of offshore lidar measurements up to 6 km has been used for this purpose. Using dual-doppler measurements, the topographic characteristics of the area have been modelled. Assuming Taylor's frozen turbulence and applying the topographic corrections, we demonstrate that we can forecast wind speeds with more accuracy than the benchmarks persistence or ARIMA.
Jakob Mann, Alfredo Peña, Niels Troldborg, and Søren J. Andersen
Wind Energ. Sci., 3, 293–300, https://doi.org/10.5194/wes-3-293-2018, https://doi.org/10.5194/wes-3-293-2018, 2018
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Turbulence is usually assumed to be unmodified by the stagnation occurring in front of a wind turbine rotor. All manufacturers assume this in their dynamic load calculations. If this assumption is not true it might bias the load calculations and the turbines might not be designed optimally. We investigate the assumption with a Doppler lidar measuring forward from the top of the nacelle and find small but systematic changes in the approaching turbulence that depend on the power curve.
Alfredo Peña, Kurt Schaldemose Hansen, Søren Ott, and Maarten Paul van der Laan
Wind Energ. Sci., 3, 191–202, https://doi.org/10.5194/wes-3-191-2018, https://doi.org/10.5194/wes-3-191-2018, 2018
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We analyze the wake of the Anholt offshore wind farm in Denmark by intercomparing models and measurements. We also look at the effect of the land on the wind farm by intercomparing mesoscale winds and measurements. Annual energy production and capacity factor estimates are performed using different approaches. Lastly, the uncertainty of the wake models is determined by bootstrapping the data; we find that the wake models generally underestimate the wake losses.
Nikola Vasiljević, José M. L. M. Palma, Nikolas Angelou, José Carlos Matos, Robert Menke, Guillaume Lea, Jakob Mann, Michael Courtney, Luis Frölen Ribeiro, and Vitor M. M. G. C. Gomes
Atmos. Meas. Tech., 10, 3463–3483, https://doi.org/10.5194/amt-10-3463-2017, https://doi.org/10.5194/amt-10-3463-2017, 2017
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In this paper we present a methodology for atmospheric multi-Doppler lidar experiments accompanied with the description and results from the Perdigão-2015 experiment, where the methodology was demonstrated. To our knowledge, this is the first time that steps leading to the acquisition of high-quality datasets from field studies are described and systematically defined and organized.
Alfredo Peña, Jakob Mann, and Nikolay Dimitrov
Wind Energ. Sci., 2, 133–152, https://doi.org/10.5194/wes-2-133-2017, https://doi.org/10.5194/wes-2-133-2017, 2017
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Nacelle lidars are nowadays extensively used to scan the turbine inflow. Thus, it is important to characterize turbulence from their measurements. We present two methods to perform turbulence estimation and demonstrate them using two types of lidars. With one method we can estimate the along-wind unfiltered variance accurately. With the other we can estimate the filtered radial velocity variance accurately and velocity-tensor parameters under neutral and high wind-speed conditions.
Ryan Kilpatrick, Horia Hangan, Kamran Siddiqui, Dan Parvu, Julia Lange, Jakob Mann, and Jacob Berg
Wind Energ. Sci., 1, 237–254, https://doi.org/10.5194/wes-1-237-2016, https://doi.org/10.5194/wes-1-237-2016, 2016
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This paper contributes to the scientific knowledge of flow behaviour over complex topography by extending the physical modelling work of the flow over the Bolund Hill escarpment, a test case for the validation of numerical models in complex terrain for wind resource assessment. The influence of inflow conditions on the flow over the topography has been examined in detail using a large-scale topographic model at high resolution at the unique WindEEE dome wind research facility.
Alfredo Peña, Andreas Bechmann, Davide Conti, and Nikolas Angelou
Wind Energ. Sci., 1, 101–114, https://doi.org/10.5194/wes-1-101-2016, https://doi.org/10.5194/wes-1-101-2016, 2016
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We have developed flow models from different complexities. Unfortunately, high quality and reliable wind observations affected by obstacles are rare and so we have few means to evaluate our models. We have therefore performed a campaign in which we measured the effect of a fence on the atmosphere using laser-based instruments. The effect can still be noticed as far as 11 fence heights. A wake theory seems to predict the obstacle effect when we are looking at distances beyond 6 fence heights.
G. A. M. van Kuik, J. Peinke, R. Nijssen, D. Lekou, J. Mann, J. N. Sørensen, C. Ferreira, J. W. van Wingerden, D. Schlipf, P. Gebraad, H. Polinder, A. Abrahamsen, G. J. W. van Bussel, J. D. Sørensen, P. Tavner, C. L. Bottasso, M. Muskulus, D. Matha, H. J. Lindeboom, S. Degraer, O. Kramer, S. Lehnhoff, M. Sonnenschein, P. E. Sørensen, R. W. Künneke, P. E. Morthorst, and K. Skytte
Wind Energ. Sci., 1, 1–39, https://doi.org/10.5194/wes-1-1-2016, https://doi.org/10.5194/wes-1-1-2016, 2016
C. F. Abari, A. T. Pedersen, E. Dellwik, and J. Mann
Atmos. Meas. Tech., 8, 4145–4153, https://doi.org/10.5194/amt-8-4145-2015, https://doi.org/10.5194/amt-8-4145-2015, 2015
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Continuous-wave coherent Doppler lidars (CW CDL) are a class of short-range wind lidars. This paper presents the measurement results from a field campaign where the performance of a recently built all-fiber image-reject homodyne CW CDL is compared against a sonic anemometer. The results are weighed against another instrument, i.e., a CW CDL benefiting from a heterodyne receiver. The results show that the new system has a superior measurement performance, especially for close-to-zero velocities.
A. Sathe, J. Mann, N. Vasiljevic, and G. Lea
Atmos. Meas. Tech., 8, 729–740, https://doi.org/10.5194/amt-8-729-2015, https://doi.org/10.5194/amt-8-729-2015, 2015
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A so-called six-beam method is proposed to measure atmospheric turbulence using a ground-based wind lidar. This method is presented as an alternative to the so-called velocity azimuth display (VAD) method that is routinely used in commercial wind lidars, and which usually results in significant averaging effects of measured turbulence.
A. Sathe and J. Mann
Atmos. Meas. Tech., 6, 3147–3167, https://doi.org/10.5194/amt-6-3147-2013, https://doi.org/10.5194/amt-6-3147-2013, 2013
E. Branlard, A. T. Pedersen, J. Mann, N. Angelou, A. Fischer, T. Mikkelsen, M. Harris, C. Slinger, and B. F. Montes
Atmos. Meas. Tech., 6, 1673–1683, https://doi.org/10.5194/amt-6-1673-2013, https://doi.org/10.5194/amt-6-1673-2013, 2013
Related subject area
Subject: Others (Wind, Precipitation, Temperature, etc.) | Technique: In Situ Measurement | Topic: Validation and Intercomparisons
Time-resolved measurements of the densities of individual frozen hydrometeors and fresh snowfall
Uncertainties in temperature statistics and fluxes determined by sonic anemometers due to wind-induced vibrations of mounting arms
Performance evaluation of MeteoTracker mobile sensor for outdoor applications
Impacts of anemometer changes, site relocations and processing methods on wind speed trends in China
Validation of Aeolus L2B products over the tropical Atlantic using radiosondes
Estimating the turbulent kinetic energy dissipation rate from one-dimensional velocity measurements in time
Evaluation of in situ observations on Marine Weather Observer during Typhoon Sinlaku
Validation of the WRF-ARW eclipse model with measurements from the 2019 and 2020 total solar eclipses
Assessing the Ducting Phenomenon and its Impact on GNSS Radio Occultation Refractivity Retrievals over the Northeast Pacific Ocean using Radiosondes and Global Reanalysis
How observations from automatic hail sensors in Switzerland shed light on local hailfall duration and compare with hailpad measurements
A data-driven persistence test for robust (probabilistic) quality control of measured environmental time series: constant value episodes
A comparative evaluation of snowflake particle shape estimation techniques used by the Precipitation Imaging Package (PIP), Multi-Angle Snowflake Camera (MASC), and Two-Dimensional Video Disdrometer (2DVD)
Comparison of GRUAN data products for Meisei iMS-100 and Vaisala RS92 radiosondes at Tateno, Japan
Validation of the Aeolus Level-2B wind product over Northern Canada and the Arctic
Boundary-layer height and surface stability at Hyytiälä, Finland, in ERA5 and observations
Characterizing and correcting the warm bias observed in Aircraft Meteorological Data Relay (AMDAR) temperature observations
Something fishy going on? Evaluating the Poisson hypothesis for rainfall estimation using intervalometers: results from an experiment in Tanzania
Suitability of fibre-optic distributed temperature sensing for revealing mixing processes and higher-order moments at the forest–air interface
Validation of Aeolus winds using radiosonde observations and numerical weather prediction model equivalents
Smartphone pressure data: quality control and impact on atmospheric analysis
Automated precipitation monitoring with the Thies disdrometer: biases and ways for improvement
More science with less: evaluation of a 3D-printed weather station
Characteristics and performance of wind profiles as observed by the radar wind profiler network of China
Confronting the boundary layer data gap: evaluating new and existing methodologies of probing the lower atmosphere
On the estimation of vertical air velocity and detection of atmospheric turbulence from the ascent rate of balloon soundings
Comparison of turbulence measurements by a CSAT3B sonic anemometer and a high-resolution bistatic Doppler lidar
Using computational fluid dynamics and field experiments to improve vehicle-based wind measurements for environmental monitoring
Comparison of the GRUAN data products for Meisei RS-11G and Vaisala RS92-SGP radiosondes at Tateno (36.06° N, 140.13° E), Japan
Using reference radiosondes to characterise NWP model uncertainty for improved satellite calibration and validation
Evaluation of OAFlux datasets based on in situ air–sea flux tower observations over Yongxing Island in 2016
Characteristics of vertical velocities estimated from drop size and fall velocity spectra of a Parsivel disdrometer
Effects of temporal averaging on short-term irradiance variability under mixed sky conditions
Comparison of Lyman-alpha and LI-COR infrared hygrometers for airborne measurement of turbulent fluctuations of water vapour
Hotplate precipitation gauge calibrations and field measurements
Field intercomparison of prevailing sonic anemometers
A new method for estimating UV fluxes at ground level in cloud-free conditions
Precipitable water characteristics during the 2013 Colorado flood using ground-based GPS measurements
Comparison of Vaisala radiosondes RS41 and RS92 launched over the oceans from the Arctic to the tropics
Comparison of hourly surface downwelling solar radiation estimated from MSG–SEVIRI and forecast by the RAMS model with pyranometers over Italy
Quantitative analysis of the radiation error for aerial coiled-fiber-optic distributed temperature sensing deployments using reinforcing fabric as support structure
An automated method for the evaluation of the pointing accuracy of Sun-tracking devices
Assessment of snowfall accumulation underestimation by tipping bucket gauges in the Spanish operational network
Compatibility of different measurement techniques of global solar radiation and application for long-term observations at Izaña Observatory
Uncertainties of ground-based microwave radiometer retrievals in zenith and off-zenith observations under snow conditions
Performance of post-processing algorithms for rainfall intensity using measurements from tipping-bucket rain gauges
Comparison of Vaisala radiosondes RS41 and RS92 at the ARM Southern Great Plains site
HOAPS and ERA-Interim precipitation over the sea: validation against shipboard in situ measurements
Quality assessment of solar UV irradiance measured with array spectroradiometers
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Performance of WVSS-II hygrometers on the FAAM research aircraft
Dhiraj K. Singh, Eric R. Pardyjak, and Timothy J. Garrett
Atmos. Meas. Tech., 17, 4581–4598, https://doi.org/10.5194/amt-17-4581-2024, https://doi.org/10.5194/amt-17-4581-2024, 2024
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Accurate measurements of the properties of snowflakes are challenging to make. We present a new technique for the real-time measurement of the density of freshly fallen individual snowflakes. A new thermal-imaging instrument, the Differential Emissivity Imaging Disdrometer (DEID), is shown to be capable of providing accurate estimates of individual snowflake and bulk snow hydrometeor density. The method exploits the rate of heat transfer during the melting of a snowflake on a hotplate.
Zhongming Gao, Heping Liu, Dan Li, Bai Yang, Von Walden, Lei Li, and Ivan Bogoev
Atmos. Meas. Tech., 17, 4109–4120, https://doi.org/10.5194/amt-17-4109-2024, https://doi.org/10.5194/amt-17-4109-2024, 2024
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Using data collected from three levels of a 62 m tower, we found that both the temperature variances and sensible heat flux obtained from sonic anemometers are consistently lower, by a few percent, compared to those from fine-wire thermocouples.
Francesco Barbano, Erika Brattich, Carlo Cintolesi, Abdul Ghafoor Nizamani, Silvana Di Sabatino, Massimo Milelli, Esther E. M. Peerlings, Sjoerd Polder, Gert-Jan Steeneveld, and Antonio Parodi
Atmos. Meas. Tech., 17, 3255–3278, https://doi.org/10.5194/amt-17-3255-2024, https://doi.org/10.5194/amt-17-3255-2024, 2024
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The characterization of the urban microclimate starts with atmospheric monitoring using a dense array of sensors to capture the spatial variations induced by the different morphology, land cover, and presence of vegetation. To provide a new sensor for this scope, this paper evaluates the outdoor performance of a commercial mobile sensor. The results mark the sensor's ability to capture the same atmospheric variability as the reference, making it a valid solution for atmospheric monitoring.
Yi Liu, Lihong Zhou, Yingzuo Qin, Cesar Azorin-Molina, Cheng Shen, Rongrong Xu, and Zhenzhong Zeng
Atmos. Meas. Tech., 17, 1123–1131, https://doi.org/10.5194/amt-17-1123-2024, https://doi.org/10.5194/amt-17-1123-2024, 2024
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Our research analyzed China's wind speed data and addressed inconsistencies caused by factors like equipment changes and station relocations. After improving data quality, China's recent wind speed decrease reduced by 41 %, revealing an increasing trend. This emphasizes the importance of rigorous data processing for accurate trend assessments in various research fields.
Maurus Borne, Peter Knippertz, Martin Weissmann, Benjamin Witschas, Cyrille Flamant, Rosimar Rios-Berrios, and Peter Veals
Atmos. Meas. Tech., 17, 561–581, https://doi.org/10.5194/amt-17-561-2024, https://doi.org/10.5194/amt-17-561-2024, 2024
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This study assesses the quality of Aeolus wind measurements over the tropical Atlantic. The results identified the accuracy and precision of the Aeolus wind measurements and the potential source of errors. For instance, the study revealed atmospheric conditions that can deteriorate the measurement quality, such as weaker laser signal in cloudy or dusty conditions, and confirmed the presence of an orbital-dependant bias. These results can help to improve the Aeolus wind measurement algorithm.
Marcel Schröder, Tobias Bätge, Eberhard Bodenschatz, Michael Wilczek, and Gholamhossein Bagheri
Atmos. Meas. Tech., 17, 627–657, https://doi.org/10.5194/amt-17-627-2024, https://doi.org/10.5194/amt-17-627-2024, 2024
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The rate at which energy is dissipated in a turbulent flow is an extremely important quantity. In the atmosphere, it is usually measured by recording a velocity time at a specific location. Our goal is to understand how best to estimate the dissipation rate from such data based on various available methods. Our reference for evaluating the performance of the different methods is data generated with direct numerical simulations and in highly controlled laboratory setups.
Wenying He, Hongbin Chen, Hongyong Yu, Jun Li, Jidong Pan, Shuqing Ma, Xuefen Zhang, Rang Guo, Bingke Zhao, Xi Chen, Xiangao Xia, and Kaicun Wang
Atmos. Meas. Tech., 17, 135–144, https://doi.org/10.5194/amt-17-135-2024, https://doi.org/10.5194/amt-17-135-2024, 2024
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The Marine Weather Observer (MWO) system completed a long-term observation, actively approaching the center of Typhoon Sinlaku on 24 July–2 August 2020, over the South China Sea. The in situ observations were evaluated through comparison with buoy observations during the evolution of Typhoon Sinlaku. As a mobile observation station, MWO has shown its unique advantages over traditional observation methods, and the results preliminarily demonstrate the reliable observation capability of MWO.
Carl E. Spangrude, Jennifer W. Fowler, W. Graham Moss, and June Wang
Atmos. Meas. Tech., 16, 5167–5179, https://doi.org/10.5194/amt-16-5167-2023, https://doi.org/10.5194/amt-16-5167-2023, 2023
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Atmospheric measurements were completed for two total solar eclipses. An eclipse-specific weather model was utilized to model the atmosphere before, during, and after the eclipse events. These measurements have enabled further validation of the model's performance in simulating atmospheric responses to total solar eclipses. The paper concludes by recommending further scientific analyses to be explored utilizing the unique datasets presented.
Thomas E. Winning, Feiqin Xie, and Kevin J. Nelson
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2023-150, https://doi.org/10.5194/amt-2023-150, 2023
Revised manuscript accepted for AMT
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The effect of ducting due to the presence of the planetary boundary layer (PBL) is prevalent over the northeastern Pacific Ocean from Los Angeles to Honolulu. The ducting induced refractivity bias in the radiosonde climatology and global reanalysis data is highly correlated with the height of the PBL. The magnitude of bias is linearly dependent on the strength of ducting but not the location and the overall reanalysis data systematically underestimates the height of the PBL by as much as 120 m.
Jérôme Kopp, Agostino Manzato, Alessandro Hering, Urs Germann, and Olivia Martius
Atmos. Meas. Tech., 16, 3487–3503, https://doi.org/10.5194/amt-16-3487-2023, https://doi.org/10.5194/amt-16-3487-2023, 2023
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We present the first study of extended field observations made by a network of 80 automatic hail sensors from Switzerland. The sensors record the exact timing of hailstone impacts, providing valuable information about the local duration of hailfall. We found that the majority of hailfalls lasts just a few minutes and that most hailstones, including the largest, fall during a first phase of high hailstone density, while a few remaining and smaller hailstones fall in a second low-density phase.
Najmeh Kaffashzadeh
Atmos. Meas. Tech., 16, 3085–3100, https://doi.org/10.5194/amt-16-3085-2023, https://doi.org/10.5194/amt-16-3085-2023, 2023
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Although quality control is a well-known issue in data application, research initiatives and organizations apply given methods based on traditional techniques (ad hoc thresholds and manual). These approaches are not only error prone but also unsuitable for a large volume of data. The method proposed in this paper is based on a new concept (probability) as an intuitive indicator and data’s characteristics, which leads it to be applicable to a wide variety of data and eases its
fit for purpose.
Charles Nelson Helms, Stephen Joseph Munchak, Ali Tokay, and Claire Pettersen
Atmos. Meas. Tech., 15, 6545–6561, https://doi.org/10.5194/amt-15-6545-2022, https://doi.org/10.5194/amt-15-6545-2022, 2022
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This study compares the techniques used to measure snowflake shape by three instruments: PIP, MASC, and 2DVD. Our findings indicate that the MASC technique produces reliable shape measurements; the 2DVD technique performs better than expected considering the instrument was designed to measure raindrops; and the PIP technique does not produce reliable snowflake shape measurements. We also demonstrate that the PIP images can be reprocessed to correct the shape measurement issues.
Shunsuke Hoshino, Takuji Sugidachi, Kensaku Shimizu, Eriko Kobayashi, Masatomo Fujiwara, and Masami Iwabuchi
Atmos. Meas. Tech., 15, 5917–5948, https://doi.org/10.5194/amt-15-5917-2022, https://doi.org/10.5194/amt-15-5917-2022, 2022
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GRUAN data products (GDPs) from Meisei iMS-100 and Vaisala RS92 were compared with 59 dual sounding data. For daytime observations, the iMS-100 temperature is around 0.5 K lower than RS92-GDP in the stratosphere, but for nighttime observations, the difference is around −0.1 K, and data are mostly in agreement. For relative humidity (RH), iMS-100 is around 1–2 % RH higher in the troposphere and 1 % RH smaller in the stratosphere than RS92, but both GDPs are in agreement for most of the profile.
Chih-Chun Chou, Paul J. Kushner, Stéphane Laroche, Zen Mariani, Peter Rodriguez, Stella Melo, and Christopher G. Fletcher
Atmos. Meas. Tech., 15, 4443–4461, https://doi.org/10.5194/amt-15-4443-2022, https://doi.org/10.5194/amt-15-4443-2022, 2022
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Aeolus is the first satellite that provides global wind profile measurements. The mission aims to improve the weather forecasts in the tropics, but also, potentially, in the polar regions. We evaluate the performance of the instrument over the Canadian North and the Arctic by comparing its measured winds in both cloudy and non-cloudy layers to wind data from forecasts, reanalysis, and ground-based instruments. Overall, good agreement was seen, but Aeolus winds have greater dispersion.
Victoria Anne Sinclair, Jenna Ritvanen, Gabin Urbancic, Irene Erner, Yurii Batrak, Dmitri Moisseev, and Mona Kurppa
Atmos. Meas. Tech., 15, 3075–3103, https://doi.org/10.5194/amt-15-3075-2022, https://doi.org/10.5194/amt-15-3075-2022, 2022
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We investigate the boundary-layer (BL) height and surface stability in southern Finland using radiosondes, a microwave radiometer and ERA5 reanalysis. Accurately quantifying the BL height is challenging, and the diagnosed BL height can depend strongly on the method used. Microwave radiometers provide reliable estimates of the BL height but only in unstable conditions. ERA5 captures the BL height well except under very stable conditions, which occur most commonly at night during the warm season.
Siebren de Haan, Paul M. A. de Jong, and Jitze van der Meulen
Atmos. Meas. Tech., 15, 811–818, https://doi.org/10.5194/amt-15-811-2022, https://doi.org/10.5194/amt-15-811-2022, 2022
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AMDAR temperatures suffer from a bias, which can be related to a difference in the timing of height and measurement and to internal corrections applied to pressure altitude. Based on NWP model temperature data, combined with Mach number and true airspeed, we could estimate corrections. Comparing corrected temperatures with (independent) radiosonde observations demonstrates a reduction in the bias, from 0.5 K to around zero, and standard deviation, of almost 10 %.
Didier de Villiers, Marc Schleiss, Marie-Claire ten Veldhuis, Rolf Hut, and Nick van de Giesen
Atmos. Meas. Tech., 14, 5607–5623, https://doi.org/10.5194/amt-14-5607-2021, https://doi.org/10.5194/amt-14-5607-2021, 2021
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Ground-based rainfall observations across the African continent are sparse. We present a new and inexpensive rainfall measuring instrument (the intervalometer) and use it to derive reasonably accurate rainfall rates. These are dependent on a fundamental assumption that is widely used in parameterisations of the rain drop size distribution. This assumption is tested and found to not apply for most raindrops but is still useful in deriving rainfall rates. The intervalometer shows good potential.
Olli Peltola, Karl Lapo, Ilkka Martinkauppi, Ewan O'Connor, Christoph K. Thomas, and Timo Vesala
Atmos. Meas. Tech., 14, 2409–2427, https://doi.org/10.5194/amt-14-2409-2021, https://doi.org/10.5194/amt-14-2409-2021, 2021
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We evaluated the suitability of fiber-optic distributed temperature sensing (DTS) for observing spatial (>25 cm) and temporal (>1 s) details of airflow within and above forests. The DTS measurements could discern up to third-order moments of the flow and observe spatial details of coherent flow motions. Similar measurements are not possible with more conventional measurement techniques. Hence, the DTS measurements will provide key insights into flows close to roughness elements, e.g. trees.
Anne Martin, Martin Weissmann, Oliver Reitebuch, Michael Rennie, Alexander Geiß, and Alexander Cress
Atmos. Meas. Tech., 14, 2167–2183, https://doi.org/10.5194/amt-14-2167-2021, https://doi.org/10.5194/amt-14-2167-2021, 2021
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This study provides an overview of validation activities to determine the Aeolus HLOS wind errors and to understand the biases by investigating possible dependencies and testing bias correction approaches. To ensure meaningful validation statistics, collocated radiosondes and two different global NWP models, the ECMWF IFS and the ICON model (DWD), are used as reference data. To achieve an estimate for the Aeolus instrumental error the representativeness errors for the comparisons are evaluated.
Rumeng Li, Qinghong Zhang, Juanzhen Sun, Yun Chen, Lili Ding, and Tian Wang
Atmos. Meas. Tech., 14, 785–801, https://doi.org/10.5194/amt-14-785-2021, https://doi.org/10.5194/amt-14-785-2021, 2021
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In this paper, we describe a bias-correction method based on machine learning without the need to obtain users' personal information and demonstrate that the method can effectively reduce the bias in smartphone pressure observations. The characteristics of this dataset are discussed, and the potential application of the bias-corrected data is illustrated by the fine-scale analysis of a hailstorm that occurred on 10 June 2016 in Beijing, China.
Michael Fehlmann, Mario Rohrer, Annakaisa von Lerber, and Markus Stoffel
Atmos. Meas. Tech., 13, 4683–4698, https://doi.org/10.5194/amt-13-4683-2020, https://doi.org/10.5194/amt-13-4683-2020, 2020
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The Thies disdrometer is used to monitor precipitation intensity and its phase and thus may provide valuable information for the management of meteorological and hydrological risks. In this study, we characterize biases of this instrument using common reference instruments at a pre-alpine study site in Switzerland. We find a systematic underestimation of liquid precipitation amounts and suggest possible reasons for and corrections to this bias and relate these findings to other study sites.
Adam Theisen, Max Ungar, Bryan Sheridan, and Bradley G. Illston
Atmos. Meas. Tech., 13, 4699–4713, https://doi.org/10.5194/amt-13-4699-2020, https://doi.org/10.5194/amt-13-4699-2020, 2020
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A low-cost weather station with 3D-printed components was built, based on the UCAR 3D-PAWS project, and deployed alongside an Oklahoma Mesonet station for an 8-month study to determine the longevity of these sensors and their performance compared with standard commercial sensors. Results show that the low-cost sensors can perform as well as the more expensive commercial ones for short-term deployments with the possibility for long-term deployments with proper maintenance and replacement.
Boming Liu, Jianping Guo, Wei Gong, Lijuan Shi, Yong Zhang, and Yingying Ma
Atmos. Meas. Tech., 13, 4589–4600, https://doi.org/10.5194/amt-13-4589-2020, https://doi.org/10.5194/amt-13-4589-2020, 2020
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Vertical wind profiles are crucial to a wide range of atmospheric disciplines. However, the wind profile across China remains poorly understood. Here we reveal the salient features of winds from the radar wind profile of China, including the main instruments, spatial coverage and sampling frequency. This work is expected to allow the public and scientific community to be more familiar with the nationwide network and encourage the use of these valuable data in future research and applications.
Tyler M. Bell, Brian R. Greene, Petra M. Klein, Matthew Carney, and Phillip B. Chilson
Atmos. Meas. Tech., 13, 3855–3872, https://doi.org/10.5194/amt-13-3855-2020, https://doi.org/10.5194/amt-13-3855-2020, 2020
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It is well known that the atmospheric boundary layer is under-sampled in the vertical dimension. Recently, weather-sensing uncrewed aerial systems (WxUAS) have created new opportunities to sample this region of the atmosphere. This study compares a WxUAS developed at the University of Oklahoma to ground-based remote sensing and radiosondes. We find that overall the systems generally agreed well both thermodynamically and kinematically. However, there is still room to improve each system.
Hubert Luce and Hiroyuki Hashiguchi
Atmos. Meas. Tech., 13, 1989–1999, https://doi.org/10.5194/amt-13-1989-2020, https://doi.org/10.5194/amt-13-1989-2020, 2020
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Vertical ascent rate Vb of meteorological balloons is sometimes used for retrieving vertical air velocity, an important parameter for meteorological applications. Comparisons with concurrent radar and unmanned aerial vehicle (UAV) measurements of atmospheric turbulence showed that Vb can be increased in turbulent layers due to the probable decrease in the drag coefficient of the balloon. We conclude that Vb can also potentially be used for the detection of atmospheric turbulence.
Matthias Mauder, Michael Eggert, Christian Gutsmuths, Stefan Oertel, Paul Wilhelm, Ingo Voelksch, Luise Wanner, Jens Tambke, and Ivan Bogoev
Atmos. Meas. Tech., 13, 969–983, https://doi.org/10.5194/amt-13-969-2020, https://doi.org/10.5194/amt-13-969-2020, 2020
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Sonic anemometers are prone to probe-induced flow distortion effects. Here, we present the results of an intercomparison experiment between a CSAT3B sonic anemometer and a high-resolution bistatic Doppler lidar, which is inherently free of flow distortion. Our results show an agreement of the mean wind velocity measurements and the standard deviations of the vertical wind speed with comparabilities of 0.082 and 0.020 m s−1, respectively. Friction velocity is underestimated by the CSAT3B by 3 %.
Tara Hanlon and David Risk
Atmos. Meas. Tech., 13, 191–203, https://doi.org/10.5194/amt-13-191-2020, https://doi.org/10.5194/amt-13-191-2020, 2020
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In this study, we aimed to improve accuracy of wind speed and direction measurements from an anemometer mounted atop a research vehicle. Controlled field tests and computer simulations showed that the vehicle shape biases airflow above the vehicle. The results indicate that placing an anemometer at a significant height (> 1 m) above the vehicle, and calibrating anemometer measurements for vehicle shape and wind angle, can be effective in reducing bias in measurements of wind speed and direction.
Eriko Kobayashi, Shunsuke Hoshino, Masami Iwabuchi, Takuji Sugidachi, Kensaku Shimizu, and Masatomo Fujiwara
Atmos. Meas. Tech., 12, 3039–3065, https://doi.org/10.5194/amt-12-3039-2019, https://doi.org/10.5194/amt-12-3039-2019, 2019
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The authors carried out dual flights of RS-11G and RS92-SGP radiosondes and investigated the differences in the performance of the radiosondes to help characterize GRUAN data products. A novel aspect of GRUAN data products is that vertically resolved uncertainty estimates and metadata are provided for each sounding and comparison of GRUAN data products is important in securing the temporal homogeneity of climate data records.
Fabien Carminati, Stefano Migliorini, Bruce Ingleby, William Bell, Heather Lawrence, Stuart Newman, James Hocking, and Andrew Smith
Atmos. Meas. Tech., 12, 83–106, https://doi.org/10.5194/amt-12-83-2019, https://doi.org/10.5194/amt-12-83-2019, 2019
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The GRUAN processor is a software developed to collocate radiosonde profiles and numerical weather prediction model fields, simulate top-of-atmosphere brightness temperature at frequencies used by space-borne instruments, and propagate the radiosonde uncertainties in that simulation. This work responds to an identified lack of metrologically traceable characterisation of uncertainties in model fields that are increasingly used for the validation and calibration of space-borne instruments.
Fenghua Zhou, Rongwang Zhang, Rui Shi, Ju Chen, Yunkai He, Dongxiao Wang, and Qiang Xie
Atmos. Meas. Tech., 11, 6091–6106, https://doi.org/10.5194/amt-11-6091-2018, https://doi.org/10.5194/amt-11-6091-2018, 2018
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In this work, successive air–sea heat flux-related data were acquired over the course of a year (01/02/2016–31/01/2017) at the YXASFT on Yongxing Island. Then, seasonal comparisons were conducted for the daily mean surface bulk variables and heat fluxes between the WHOI OAFlux products and YXASFT observations. The conclusions in this paper will provide useful reference for researchers on how to select the appropriate OAFlux datasets in different seasons over the South China Sea.
Dong-Kyun Kim and Chang-Keun Song
Atmos. Meas. Tech., 11, 3851–3860, https://doi.org/10.5194/amt-11-3851-2018, https://doi.org/10.5194/amt-11-3851-2018, 2018
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A new technique to estimate vertical velocities from Parsivel-measured drop and velocity spectra is developed. The estimated vertical velocities (w) were compared with w components of winds measured from the anemometer at the same site. They showed good agreement with each other, suggesting that this technique is reliable and applicable to rainfall studies. With these w values, rainfall characteristics related to up-/downdraft were investigated on the windward and leeward sides of a mountain.
Gerald M. Lohmann and Adam H. Monahan
Atmos. Meas. Tech., 11, 3131–3144, https://doi.org/10.5194/amt-11-3131-2018, https://doi.org/10.5194/amt-11-3131-2018, 2018
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Using high-resolution surface irradiance data with original temporal resolutions between 0.01 s and 1 s from six different locations in the Northern Hemisphere, we characterize the changes in representation of temporal variability resulting from time averaging. Our results indicate that a temporal averaging time scale of around 1 s marks a transition in representing single-point irradiance variability, such that longer averages result in substantial underestimates of variability.
Astrid Lampert, Jörg Hartmann, Falk Pätzold, Lennart Lobitz, Peter Hecker, Katrin Kohnert, Eric Larmanou, Andrei Serafimovich, and Torsten Sachs
Atmos. Meas. Tech., 11, 2523–2536, https://doi.org/10.5194/amt-11-2523-2018, https://doi.org/10.5194/amt-11-2523-2018, 2018
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We compared two different fast-response humidity sensors simultaneously on different airborne platforms. One is a particular, well-establed Lyman-alpha hygrometer that has been used for decades as the standard for fast airborne humidity measurements. However, it is not available any more. The other one is a hygrometer based on the absorption of infrared radiation, from LI-COR. For an environment of low vibrations, the LI-COR sensor is suitable for fast airborne water vapour measurements.
Nicholas Zelasko, Adam Wettlaufer, Bujidmaa Borkhuu, Matthew Burkhart, Leah S. Campbell, W. James Steenburgh, and Jefferson R. Snider
Atmos. Meas. Tech., 11, 441–458, https://doi.org/10.5194/amt-11-441-2018, https://doi.org/10.5194/amt-11-441-2018, 2018
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The hotplate precipitation gauge has the potential to solve some problems with conventional precipitation gauge measurements, especially for snowfall. This paper extends the seminal published work, Rasmussen et al. (2011). We assert that the precipitation rate algorithm we have developed for the hotplate is an improvement on that which was previously published.
Matthias Mauder and Matthias J. Zeeman
Atmos. Meas. Tech., 11, 249–263, https://doi.org/10.5194/amt-11-249-2018, https://doi.org/10.5194/amt-11-249-2018, 2018
William Wandji Nyamsi, Mikko R. A. Pitkänen, Youva Aoun, Philippe Blanc, Anu Heikkilä, Kaisa Lakkala, Germar Bernhard, Tapani Koskela, Anders V. Lindfors, Antti Arola, and Lucien Wald
Atmos. Meas. Tech., 10, 4965–4978, https://doi.org/10.5194/amt-10-4965-2017, https://doi.org/10.5194/amt-10-4965-2017, 2017
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This paper proposes a new, fast and accurate method for estimating UV fluxes at ground level in cloud-free conditions at any place and time. The method performs very well with the Copernicus Atmosphere Monitoring Service products as inputs describing the state of the atmosphere. An accuracy that is close to the uncertainty of the measurements themselves is reached. We believe that our research will be widely used in the near future.
Hannah K. Huelsing, Junhong Wang, Carl Mears, and John J. Braun
Atmos. Meas. Tech., 10, 4055–4066, https://doi.org/10.5194/amt-10-4055-2017, https://doi.org/10.5194/amt-10-4055-2017, 2017
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The precipitable water (PW) was examined for the 2013 Colorado flood to determine how climatologically abnormal this event was. The seasonal PW maximum extended into early September and the September monthly mean PW exceeded the 99th percentile of climatology with a value 25% higher than the 40-year climatology. The above-normal, near-saturation PW values during the flood were the result of large-scale moisture transport into Colorado from the eastern tropical Pacific and the Gulf of Mexico.
Yoshimi Kawai, Masaki Katsumata, Kazuhiro Oshima, Masatake E. Hori, and Jun Inoue
Atmos. Meas. Tech., 10, 2485–2498, https://doi.org/10.5194/amt-10-2485-2017, https://doi.org/10.5194/amt-10-2485-2017, 2017
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The model RS92 radiosonde manufactured by Vaisala Ltd. is now being replaced with a successor model, the RS41, and we need to clarify accuracy differences between them for a variety of research. For this purpose, 36 twin-radiosonde flights were performed over the oceans from the Arctic to the tropics. Basically the differences between the RS41 and RS92 were smaller than the nominal combined uncertainties of the RS41; however, we found non-negligible biases in relative humidity and pressure.
Stefano Federico, Rosa Claudia Torcasio, Paolo Sanò, Daniele Casella, Monica Campanelli, Jan Fokke Meirink, Ping Wang, Stefania Vergari, Henri Diémoz, and Stefano Dietrich
Atmos. Meas. Tech., 10, 2337–2352, https://doi.org/10.5194/amt-10-2337-2017, https://doi.org/10.5194/amt-10-2337-2017, 2017
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In this paper we evaluate the performance of two estimates of the global horizontal irradiance (GHI), one derived from the Meteosat Second Generation and one from a meteorological model (Regional Atmospheric Modeling System) forecast. The focus area is Italy, and the performance is evaluated for 12 pyranometers spanning a range of climate conditions, from Mediterranean maritime to Alpine.
Armin Sigmund, Lena Pfister, Chadi Sayde, and Christoph K. Thomas
Atmos. Meas. Tech., 10, 2149–2162, https://doi.org/10.5194/amt-10-2149-2017, https://doi.org/10.5194/amt-10-2149-2017, 2017
Dietmar J. Baumgartner, Werner Pötzi, Heinrich Freislich, Heinz Strutzmann, Astrid M. Veronig, and Harald E. Rieder
Atmos. Meas. Tech., 10, 1181–1190, https://doi.org/10.5194/amt-10-1181-2017, https://doi.org/10.5194/amt-10-1181-2017, 2017
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In this work we present KSO-STREAMS (KSO-SunTRackEr Accuracy Monitoring System), a platform-independent, fully automated, and cost-effective system to evaluate the pointing accuracy of Sun-tracking devices as well as its application at the Kanzelhöhe Observatory (KSO) Austrian radiation monitoring network (ARAD) site and to the results from a 15-week evaluating period.
Samuel T. Buisán, Michael E. Earle, José Luís Collado, John Kochendorfer, Javier Alastrué, Mareile Wolff, Craig D. Smith, and Juan I. López-Moreno
Atmos. Meas. Tech., 10, 1079–1091, https://doi.org/10.5194/amt-10-1079-2017, https://doi.org/10.5194/amt-10-1079-2017, 2017
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Within the framework of the WMO-SPICE (Solid Precipitation Intercomparison Experiment) the Thies tipping bucket precipitation gauge, widely used at AEMET, was assessed against the SPICE reference.
Most countries use tipping buckets and for this reason the underestimation of snowfall precipitation is a large-scale problem.
The methodology presented here can be used by other national weather services to test precipitation bias corrections and to identify regions where errors are higher.
Rosa Delia García, Emilio Cuevas, Omaira Elena García, Ramón Ramos, Pedro Miguel Romero-Campos, Fernado de Ory, Victoria Eugenia Cachorro, and Angel de Frutos
Atmos. Meas. Tech., 10, 731–743, https://doi.org/10.5194/amt-10-731-2017, https://doi.org/10.5194/amt-10-731-2017, 2017
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A 1-year intercomparison of classical and modern radiation and sunshine duration instruments has been performed at Izaña Atmospheric Observatory. We compare global solar radiation (GSR) records measured with a Kipp & Zonen CM-21 pyranometer, taken in the framework of the Baseline Surface Radiation Network, with those measured with a multifilter rotating shadowband radiometer and a bimetallic pyranometer, and with GSR estimated from sunshine duration performed with a CS sunshine recorder.
Wengang Zhang, Guirong Xu, Yuanyuan Liu, Guopao Yan, Dejun Li, and Shengbo Wang
Atmos. Meas. Tech., 10, 155–165, https://doi.org/10.5194/amt-10-155-2017, https://doi.org/10.5194/amt-10-155-2017, 2017
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A comparison between a microwave radiometer and radiosonde is carried out, and performances of zenith and off-zenith observations during snowfall are shown. In off-zenith observations, the effect of snow is obviously mitigated, and the deviation between microwave radiometer and radiosonde is small. With the aid of off-zenith observation, reliable thermodynamic atmospheric profiles can be collected, and those will be useful for the analysis and forecasting of severe convective weather.
Mattia Stagnaro, Matteo Colli, Luca Giovanni Lanza, and Pak Wai Chan
Atmos. Meas. Tech., 9, 5699–5706, https://doi.org/10.5194/amt-9-5699-2016, https://doi.org/10.5194/amt-9-5699-2016, 2016
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The research presented in this work involves field data analysis, numerical modelling techniques and approaches to a long-standing problem of liquid precipitation measurements: the sampling and the interpretation of the tipping-bucket sensor signal. The present study shows relevant implications of the adopted data processing methods for the accuracy of the rainfall intensity measurements provided by traditional tipping-bucket gauges.
Michael P. Jensen, Donna J. Holdridge, Petteri Survo, Raisa Lehtinen, Shannon Baxter, Tami Toto, and Karen L. Johnson
Atmos. Meas. Tech., 9, 3115–3129, https://doi.org/10.5194/amt-9-3115-2016, https://doi.org/10.5194/amt-9-3115-2016, 2016
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An intercomparison of Vaisala's latest-generation radiosonde RS41 and the widely used RS92 was performed in north-central Oklahoma, USA, during June 2014. The results indicate that for the conditions observed during the intercomparison the measurements of pressure, temperature, humidity, and winds agree to within the manufacturer-specified combined uncertainties. Some important exceptions were noted when exiting liquid cloud layers where evaporative cooling has less impact for RS41 measurements.
Karl Bumke, Gert König-Langlo, Julian Kinzel, and Marc Schröder
Atmos. Meas. Tech., 9, 2409–2423, https://doi.org/10.5194/amt-9-2409-2016, https://doi.org/10.5194/amt-9-2409-2016, 2016
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Satellite-derived HOAPS and ERA-Interim reanalysis data were validated against shipboard precipitation measurements. Results show that HOAPS detects the frequency of precipitation well, while ERA-Interim strongly overestimates it, especially at low latitudes. However, HOAPS underestimates precipitation rates, while ERA-Interim's Atlantic-wide precipitation rate is close to measurements. ERA-Interim strongly overestimates it in the intertropical convergence zone and southern subtropics.
Luca Egli, Julian Gröbner, Gregor Hülsen, Luciano Bachmann, Mario Blumthaler, Jimmy Dubard, Marina Khazova, Richard Kift, Kees Hoogendijk, Antonio Serrano, Andrew Smedley, and José-Manuel Vilaplana
Atmos. Meas. Tech., 9, 1553–1567, https://doi.org/10.5194/amt-9-1553-2016, https://doi.org/10.5194/amt-9-1553-2016, 2016
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Array spectroradiometers are small, light, robust and cost-effective instruments, and are increasingly used for atmospheric measurements. The quality of array spectroradiometers is assessed for the reliable quantification of ultraviolet radiation (UV) in order to monitor the exposure of UV radiation to human health. The study shows that reliable UV measurements with these instruments are limited for observations around noon and show large biases in the morning and evening.
K.-L. Chang, S. Guillas, and V. E. Fioletov
Atmos. Meas. Tech., 8, 4487–4505, https://doi.org/10.5194/amt-8-4487-2015, https://doi.org/10.5194/amt-8-4487-2015, 2015
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The aim of this article is to analyze the total column ozone data from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC) that consists of around 150 stations irregularly spaced over the globe. Our use of a new statistical spatial technique over the globe can greatly outperform the currently used spatial approximation of the total column ozone in terms of approximation. We feel that this technique could benefit the ozone science community.
A. K. Vance, S. J. Abel, R. J. Cotton, and A. M. Woolley
Atmos. Meas. Tech., 8, 1617–1625, https://doi.org/10.5194/amt-8-1617-2015, https://doi.org/10.5194/amt-8-1617-2015, 2015
Short summary
Short summary
Comparisons on the FAAM BAe 146-301 aircraft show good agreement between chilled mirror hygrometers and a WVSS-II fed from a modified Rosemount inlet (wvssR) in coud-free conditions, but a WVSS-II fed from the standard flush inlet (wvssF) over-reads, except at higher humidities. Case studies in cloudy conditions show that wvssF is immune to liquid water and ice, whilst wvssR is susceptible to both. Both WVSS-II inlets respond much more rapidly than the chilled mirror devices, especially wvssF.
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Short summary
We propose a method to assess the accuracy of turbulence measurements by sonic anemometers. The idea is to compute the ratio of the vertical to along-wind velocity spectrum within the inertial subrange. We found that the Metek USA-1 and the Campbell CSAT3 sonic anemometers do not show the expected theoretical ratio. A wind-tunnel-based correction recovers the expected ratio for the USA-1. A correction for the CSAT3 does not, illustrating that this sonic anemometer suffers from flow distortion.
We propose a method to assess the accuracy of turbulence measurements by sonic anemometers. The...
