- About
- Editorial & advisory board
- Articles
- Special issues
- Highlight articles
- Manuscript tracking
- Subscribe to alerts
- Peer review
- For authors
- For reviewers
- EGU publications
- Imprint
- Data protection
Journal cover
Journal topic
Atmospheric Chemistry and Physics
An interactive open-access journal of the European Geosciences Union
Journal topic
- About
- Editorial & advisory board
- Articles
- Special issues
- Highlight articles
- Manuscript tracking
- Subscribe to alerts
- Peer review
- For authors
- For reviewers
- EGU publications
- Imprint
- Data protection
Journal metrics
Journal metrics
IF 5.668
6.201CiteScore
6.13SNIP 1.633
SJR 2.938
index 174h5-index 87
Abstracted/indexed
Abstracted/indexed
ACP | Articles | Volume 19, issue 4
Atmos. Chem. Phys., 19, 2713–2723, 2019
https://doi.org/10.5194/acp-19-2713-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-19-2713-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
Special issue: Flow in complex terrain: the Perdigão campaigns (WES/ACP/AMT...
Atmos. Chem. Phys., 19, 2713–2723, 2019
https://doi.org/10.5194/acp-19-2713-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-19-2713-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article 01 Mar 2019
Research article | 01 Mar 2019
Characterization of flow recirculation zones at the Perdigão site using multi-lidar measurements
Robert Menke et al.Related authors
Robert Menke, Nikola Vasiljević, Johannes Wagner, Steven P. Oncley, and Jakob Mann
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-85, https://doi.org/10.5194/wes-2019-85, 2019
Manuscript under review for WES
Short summary
Short summary
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 of wind resource estimations in complex terrain making such areas more interesting for future development.
Tyler Bell, Petra Klein, Norman Wildmann, and Robert Menke
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2018-417, https://doi.org/10.5194/amt-2018-417, 2019
Revised manuscript under review for AMT
Short summary
Short summary
This study investigates the utility of using multi-Doppler retrievals during the Perdigão 2017 campaign. By combining scans from the multitude of Doppler lidars, it was possible to derive virtual towers that greatly extend the range of traditional in-situ meteorological towers. Uncertainties from the measurements are analyzed and discussed. Despite multiple sources of error, it was found that the virtual towers are useful for analyzing the complex flows observed during the campaign.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Norman Wildmann, Nicola Bodini, Julie K. Lundquist, Ludovic Bariteau, and Johannes Wagner
Atmos. Meas. Tech., 12, 6401–6423, https://doi.org/10.5194/amt-12-6401-2019, https://doi.org/10.5194/amt-12-6401-2019, 2019
Short summary
Short summary
Turbulence is the variation of wind velocity on short timescales. In this study we introduce a new method to measure turbulence in a two-dimensionial plane with lidar instruments. The method allows for the detection and quantification of subareas of distinct turbulence conditions in the observed plane. We compare the results to point and profile measurements with more established instruments. It is shown that turbulence below low-level jets and in wind turbine wakes can be investigated this way.
Patrick Murphy, Julie K. Lundquist, and Paul Fleming
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-86, https://doi.org/10.5194/wes-2019-86, 2019
Manuscript under review for WES
Short summary
Short summary
We present and evaluate an improved method for predicting wind turbine power production based on measurements of the wind speed and direction profile across the rotor disk for a wind turbine in complex terrain. By comparing predictions to actual power production from a utility-scale wind turbine, we show this method is more accurate than methods based on hub-height wind speed or surface-based atmospheric characterization.
Robert Menke, Nikola Vasiljević, Johannes Wagner, Steven P. Oncley, and Jakob Mann
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-85, https://doi.org/10.5194/wes-2019-85, 2019
Manuscript under review for WES
Short summary
Short summary
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 of wind resource estimations in complex terrain making such areas more interesting for future development.
Laura Bianco, Irina V. Djalalova, James M. Wilczak, Joseph B. Olson, Jaymes S. Kenyon, Aditya Choukulkar, Larry K. Berg, Harindra J. S. Fernando, Eric P. Grimit, Raghavendra Krishnamurthy, Julie K. Lundquist, Paytsar Muradyan, Mikhail Pekour, Yelena Pichugina, Mark T. Stoelinga, and David D. Turner
Geosci. Model Dev., 12, 4803–4821, https://doi.org/10.5194/gmd-12-4803-2019, https://doi.org/10.5194/gmd-12-4803-2019, 2019
Short summary
Short summary
During the second Wind Forecast Improvement Project, improvements to the parameterizations were applied to the High Resolution Rapid Refresh model and its nested version. The impacts of the new parameterizations on the forecast of 80 m wind speeds and power are assessed, using sodars and profiling lidars observations for comparison. Improvements are evaluated as a function of the model’s initialization time, forecast horizon, time of the day, season, site elevation, and meteorological phenomena.
Felix Kelberlau and Jakob Mann
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-71, https://doi.org/10.5194/wes-2019-71, 2019
Manuscript under review for WES
Short summary
Short summary
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 blows aligned with one of the lidar beams.
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
Short summary
Short summary
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.
Antonia Englberger, Andreas Dörnbrack, and Julie K. Lundquist
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-45, https://doi.org/10.5194/wes-2019-45, 2019
Revised manuscript under review for WES
Short summary
Short summary
At night, the wind direction often changes with height, and this veer affects structures near the surface like wind turbines. Wind turbines usually rotate clockwise, but this rotational direction interacts with veer to impact the flow field behind a wind turbine. If another turbine is located downwind, the direction of the upwind turbine's rotation will affect the downwind turbine's power production.
Charlotte B. Hasager, Andrea N. Hahmann, Tobias Ahsbahs, Ioanna Karagali, Tija Sile, Merete Badger, and Jakob Mann
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-38, https://doi.org/10.5194/wes-2019-38, 2019
Revised manuscript under review for WES
Short summary
Short summary
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.
Nikola Vasiljević, Michael Harris, Anders Tegtmeier Pedersen, Gunhild Rolighed Thorsen, Mark Pitter, Jane Harris, Kieran Bajpai, and Michael Courtney
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2019-102, https://doi.org/10.5194/amt-2019-102, 2019
Revised manuscript under review for AMT
Short summary
Short summary
In this paper we present the preliminary results of the proof of concept stage of a drone-based wind lidar system development. To test the POC drone-lidar system we hovered the drone next to mast-mounted sonic anemometers at the Risø test center. The preliminary results of the intercomparison between the measurements derived from the POC system and one of the sonic anemometers show good agreement.
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
Short summary
Short summary
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..
Simon K. Siedersleben, Andreas Platis, Julie K. Lundquist, Bughsin Djath, Astrid Lampert, Konrad Bärfuss, Beatriz Canadillas, Johannes Schultz-Stellenfleth, Jens Bange, Tom Neumann, and Stefan Emeis
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2019-100, https://doi.org/10.5194/gmd-2019-100, 2019
Manuscript under review for GMD
Short summary
Short summary
Wind farms affect local weather and microclimates. These effects can be simulated in weather models, usually by removing momentum at the location of the wind farm. Some debate exists whether additional turbulence should be added to capture the enhanced mixing of wind farms. By comparing simulations to measurements from airborne campaigns near offshore wind farms, we show that additional turbulence is necessary. Without added turbulence, the mixing is underestimated during stable conditions.
Philipp Gasch, Andreas Wieser, Julie K. Lundquist, and Norbert Kalthoff
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2019-118, https://doi.org/10.5194/amt-2019-118, 2019
Manuscript under review for AMT
Short summary
Short summary
We present an airborne Doppler lidar simulator (ADLS) based on high resolution atmospheric wind fields (LES), which is used to evaluate the retrieval accuracy of airborne wind profiling under inhomogeneous wind field conditions. For the conditions considered, flow inhomogeneities exert the dominant influence on wind profiling error. In comparison, errors due to measurement system inaccuracies are smaller. The ADLS allows for determination of preferable system setups and retrieval strategies.
Paul Fleming, Jennifer King, Katherine Dykes, Eric Simley, Jason Roadman, Andrew Scholbrock, Patrick Murphy, Julie K. Lundquist, Patrick Moriarty, Katherine Fleming, Jeroen van Dam, Christopher Bay, Rafael Mudafort, Hector Lopez, Jason Skopek, Michael Scott, Brady Ryan, Charles Guernsey, and Dan Brake
Wind Energ. Sci., 4, 273–285, https://doi.org/10.5194/wes-4-273-2019, https://doi.org/10.5194/wes-4-273-2019, 2019
Short summary
Short summary
Wake steering is a form of wind farm control in which turbines use yaw offsets to affect wakes in order to yield an increase in total energy production. In this first phase of a study of wake steering at a commercial wind farm, two turbines implement a schedule of offsets. For two closely spaced turbines, an approximate 14 % increase in energy was measured on the downstream turbine over a 10° sector, with a 4 % increase in energy production of the combined turbine pair.
Miguel Sanchez Gomez and Julie K. Lundquist
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-22, https://doi.org/10.5194/wes-2019-22, 2019
Revised manuscript accepted for WES
Short summary
Short summary
Wind turbine performance depends on various atmospheric conditions. We quantified the effect of the change in wind direction with height on turbine power output at a wind farm in Iowa. We found that turbine performance was primarily undermined for below rated wind speeds. Also, performance was more severely affected during a time period of increasing electricity demand. These effects make direction shear significant when analyzing different atmospheric regimes and for wind resource assessment.
Nikola Vasiljević, Andrea Vignaroli, Andreas Bechmann, and Rozenn Wagner
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-13, https://doi.org/10.5194/wes-2019-13, 2019
Revised manuscript accepted for WES
Short summary
Short summary
A WindScanner system consisting of two synchronized scanning lidar potentially represents a cost-effective solution for multi-point measurements. However, the lidar limitations and the site limitations are detrimental to the installation of lidars and number and location of measurement positions. To simplify the process of finding suitable measurement positions and lidar installation locations campaign planning workflow was devised. The paper describes the workflow and how it was digitized.
Nicola Bodini, Julie K. Lundquist, Raghavendra Krishnamurthy, Mikhail Pekour, Larry K. Berg, and Aditya Choukulkar
Atmos. Chem. Phys., 19, 4367–4382, https://doi.org/10.5194/acp-19-4367-2019, https://doi.org/10.5194/acp-19-4367-2019, 2019
Short summary
Short summary
To improve the parameterization of the turbulence dissipation rate (ε) in numerical weather prediction models, we have assessed its temporal and spatial variability at various scales in the Columbia River Gorge during the WFIP2 field experiment. The turbulence dissipation rate shows large spatial variability, even at the microscale, with larger values in sites located downwind of complex orographic structures or in wind farm wakes. Distinct diurnal and seasonal cycles in ε have also been found.
Jonas Kazda and Jakob Mann
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-10, https://doi.org/10.5194/wes-2019-10, 2019
Manuscript under review for WES
Short summary
Short summary
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 is then investigated.
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
Short summary
Short summary
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.
Tyler Bell, Petra Klein, Norman Wildmann, and Robert Menke
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2018-417, https://doi.org/10.5194/amt-2018-417, 2019
Revised manuscript under review for AMT
Short summary
Short summary
This study investigates the utility of using multi-Doppler retrievals during the Perdigão 2017 campaign. By combining scans from the multitude of Doppler lidars, it was possible to derive virtual towers that greatly extend the range of traditional in-situ meteorological towers. Uncertainties from the measurements are analyzed and discussed. Despite multiple sources of error, it was found that the virtual towers are useful for analyzing the complex flows observed during the campaign.
Alfredo Peña, Ebba Dellwik, and Jakob Mann
Atmos. Meas. Tech., 12, 237–252, https://doi.org/10.5194/amt-12-237-2019, https://doi.org/10.5194/amt-12-237-2019, 2019
Short summary
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.
Elliot Simon, Michael Courtney, and Nikola Vasiljevic
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2018-71, https://doi.org/10.5194/wes-2018-71, 2018
Short summary
Short summary
Remotely measured winds upstream of a wind farm presents the opportunity for improving wind energy forecasts on minute timescales. Forward looking information about conditions which advect to some degree downwind provides useful information not available in existing methods. In order to explore this, a field experiment was conduced using scanning lidar to measure winds 7 km ahead of a reference met-mast. Using this dataset, an online learning forecast system has been demonstrated and benchmarked.
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
Short summary
Short summary
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.
Joseph C. Y. Lee, M. Jason Fields, and Julie K. Lundquist
Wind Energ. Sci., 3, 845–868, https://doi.org/10.5194/wes-3-845-2018, https://doi.org/10.5194/wes-3-845-2018, 2018
Short summary
Short summary
To find the ideal way to quantify long-term wind-speed variability, we compare 27 metrics using 37 years of wind and energy data. We conclude that the robust coefficient of variation can effectively assess and correlate wind-speed and energy-production variabilities. We derive adequate results via monthly mean data, whereas uncertainty arises in interannual variability calculations. We find that reliable estimates of wind-speed variability require 10 ± 3 years of monthly mean wind data.
Jessica M. Tomaszewski, Julie K. Lundquist, Matthew J. Churchfield, and Patrick J. Moriarty
Wind Energ. Sci., 3, 833–843, https://doi.org/10.5194/wes-3-833-2018, https://doi.org/10.5194/wes-3-833-2018, 2018
Short summary
Short summary
Wind energy development has increased rapidly in rural locations of the United States, areas that also serve general aviation airports. The spinning rotor of a wind turbine creates an area of increased turbulence, and we question if this turbulent air could pose rolling hazards for light aircraft flying behind turbines. We analyze high-resolution simulations of wind flowing past a turbine to quantify the rolling risk and find that wind turbines pose no significant roll hazards to light aircraft.
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
Short summary
Short summary
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.
Nicola Bodini, Julie K. Lundquist, and Rob K. Newsom
Atmos. Meas. Tech., 11, 4291–4308, https://doi.org/10.5194/amt-11-4291-2018, https://doi.org/10.5194/amt-11-4291-2018, 2018
Short summary
Short summary
Turbulence within the atmospheric boundary layer is critically important to transfer heat, momentum, and moisture. Currently, improved turbulence parametrizations are crucially needed to refine the accuracy of model results at fine horizontal scales. In this study, we calculate turbulence dissipation rate from sonic anemometers and discuss a novel approach to derive turbulence dissipation from profiling lidar measurements.
Norman Wildmann, Nikola Vasiljevic, and Thomas Gerz
Atmos. Meas. Tech., 11, 3801–3814, https://doi.org/10.5194/amt-11-3801-2018, https://doi.org/10.5194/amt-11-3801-2018, 2018
Short summary
Short summary
Wind turbines extract energy from the flow which manifests in a region of lower wind speeds and increased turbulence downstream of the rotor, the so-called wake. Understanding the characteristics of the wake is a key challenge for wind-energy research. A new strategy for measuring the wind in the wake with three synchronized lidar instruments is presented. The measurement points are automatically adapted to the prevailing wind direction to achieve continuous monitoring of wake properties.
Rochelle P. Worsnop, Michael Scheuerer, Thomas M. Hamill, and Julie K. Lundquist
Wind Energ. Sci., 3, 371–393, https://doi.org/10.5194/wes-3-371-2018, https://doi.org/10.5194/wes-3-371-2018, 2018
Short summary
Short summary
This paper uses four statistical methods to generate probabilistic wind speed and power ramp forecasts from the High Resolution Rapid Refresh model. The results show that these methods can provide necessary uncertainty information of power ramp forecasts. These probabilistic forecasts can aid in decisions regarding power production and grid integration of wind power.
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
Short summary
Short summary
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.
Joseph C. Y. Lee and Julie K. Lundquist
Geosci. Model Dev., 10, 4229–4244, https://doi.org/10.5194/gmd-10-4229-2017, https://doi.org/10.5194/gmd-10-4229-2017, 2017
Short summary
Short summary
We evaluate the wind farm parameterization (WFP) in the Weather Research and Forecasting (WRF) model, a powerful tool to simulate wind farms and their meteorological impacts numerically. In our case study, the WFP simulations with fine vertical grid resolution are skilful in matching the observed winds and the actual power productions. Moreover, the WFP tends to underestimate power in windy conditions. We also illustrate that the modeled wind speed is a critical determinant to improve the WFP.
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
Short summary
Short summary
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.
Nicola Bodini, Dino Zardi, and Julie K. Lundquist
Atmos. Meas. Tech., 10, 2881–2896, https://doi.org/10.5194/amt-10-2881-2017, https://doi.org/10.5194/amt-10-2881-2017, 2017
Short summary
Short summary
Wind turbine wakes have considerable impacts on downwind turbines in wind farms, given their slower wind speeds and increased turbulence. Based on lidar measurements, we apply a quantitative algorithm to assess wake parameters for wakes from a row of four turbines in CWEX-13 campaign. We describe how wake characteristics evolve, and for the first time we quantify the relation between wind veer and a stretching of the wake structures, and we highlight different results for inner and outer wakes.
Clara M. St. Martin, Julie K. Lundquist, Andrew Clifton, Gregory S. Poulos, and Scott J. Schreck
Wind Energ. Sci., 2, 295–306, https://doi.org/10.5194/wes-2-295-2017, https://doi.org/10.5194/wes-2-295-2017, 2017
Short summary
Short summary
We use upwind and nacelle-based measurements from a wind turbine and investigate the influence of atmospheric stability and turbulence regimes on nacelle transfer functions (NTFs) used to correct nacelle-mounted anemometer measurements. This work shows that correcting nacelle winds using NTFs results in similar energy production estimates to those obtained using upwind tower-based wind speeds. Further, stability and turbulence metrics have been found to have an effect on NTFs below rated speed.
Laura Bianco, Katja Friedrich, James M. Wilczak, Duane Hazen, Daniel Wolfe, Ruben Delgado, Steven P. Oncley, and Julie K. Lundquist
Atmos. Meas. Tech., 10, 1707–1721, https://doi.org/10.5194/amt-10-1707-2017, https://doi.org/10.5194/amt-10-1707-2017, 2017
Short summary
Short summary
XPIA is a study held in 2015 at NOAA's Boulder Atmospheric Observatory facility, aimed at assessing remote-sensing capabilities for wind energy applications. We use well-defined reference systems to validate temperature retrieved by two microwave radiometers (MWRs) and virtual temperature measured by wind profiling radars with radio acoustic sounding systems (RASSs). Water vapor density and relative humidity by the MWRs were also compared with similar measurements from the reference systems.
Rob K. Newsom, W. Alan Brewer, James M. Wilczak, Daniel E. Wolfe, Steven P. Oncley, and Julie K. Lundquist
Atmos. Meas. Tech., 10, 1229–1240, https://doi.org/10.5194/amt-10-1229-2017, https://doi.org/10.5194/amt-10-1229-2017, 2017
Short summary
Short summary
Doppler lidars are remote sensing instruments that use infrared light to measure wind velocity in the lowest 2 to 3 km of the atmosphere. Quantifying the uncertainty in these measurements is crucial for applications ranging from wind resource assessment to model data assimilation. In this study, we evaluate three methods for estimating the random uncertainty by comparing the lidar wind measurements with nearly collocated in situ wind measurements at multiple levels on a tall tower.
Mithu Debnath, Giacomo Valerio Iungo, W. Alan Brewer, Aditya Choukulkar, Ruben Delgado, Scott Gunter, Julie K. Lundquist, John L. Schroeder, James M. Wilczak, and Daniel Wolfe
Atmos. Meas. Tech., 10, 1215–1227, https://doi.org/10.5194/amt-10-1215-2017, https://doi.org/10.5194/amt-10-1215-2017, 2017
Short summary
Short summary
The XPIA experiment was conducted in 2015 at the Boulder Atmospheric Observatory to estimate capabilities of various remote-sensing techniques for the characterization of complex atmospheric flows. Among different tests, XPIA provided the unique opportunity to perform simultaneous virtual towers with Ka-band radars and scanning Doppler wind lidars. Wind speed and wind direction were assessed against lidar profilers and sonic anemometer data, highlighting a good accuracy of the data retrieved.
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
Short summary
Short summary
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.
Mithu Debnath, G. Valerio Iungo, Ryan Ashton, W. Alan Brewer, Aditya Choukulkar, Ruben Delgado, Julie K. Lundquist, William J. Shaw, James M. Wilczak, and Daniel Wolfe
Atmos. Meas. Tech., 10, 431–444, https://doi.org/10.5194/amt-10-431-2017, https://doi.org/10.5194/amt-10-431-2017, 2017
Short summary
Short summary
Triple RHI scans were performed with three simultaneous scanning Doppler wind lidars and assessed with lidar profiler and sonic anemometer data. This test is part of the XPIA experiment. The scan strategy consists in two lidars performing co-planar RHI scans, while a third lidar measures the transversal velocity component. The results show that horizontal velocity and wind direction are measured with good accuracy, while the vertical velocity is typically measured with a significant error.
Katherine McCaffrey, Paul T. Quelet, Aditya Choukulkar, James M. Wilczak, Daniel E. Wolfe, Steven P. Oncley, W. Alan Brewer, Mithu Debnath, Ryan Ashton, G. Valerio Iungo, and Julie K. Lundquist
Atmos. Meas. Tech., 10, 393–407, https://doi.org/10.5194/amt-10-393-2017, https://doi.org/10.5194/amt-10-393-2017, 2017
Short summary
Short summary
During the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) field campaign, the wake and flow distortion from a 300-meter meteorological tower was identified using pairs of sonic anemometers mounted on opposite sides of the tower, as well as profiling and scanning lidars. Wind speed deficits up to 50% and TKE increases of 2 orders of magnitude were observed at wind directions in the wake, along with wind direction differences (flow deflection) outside of the wake.
Aditya Choukulkar, W. Alan Brewer, Scott P. Sandberg, Ann Weickmann, Timothy A. Bonin, R. Michael Hardesty, Julie K. Lundquist, Ruben Delgado, G. Valerio Iungo, Ryan Ashton, Mithu Debnath, Laura Bianco, James M. Wilczak, Steven Oncley, and Daniel Wolfe
Atmos. Meas. Tech., 10, 247–264, https://doi.org/10.5194/amt-10-247-2017, https://doi.org/10.5194/amt-10-247-2017, 2017
Short summary
Short summary
This paper discusses trade-offs among various wind measurement strategies using scanning Doppler lidars. It is found that the trade-off exists between being able to make highly precise point measurements versus covering large spatial extents. The highest measurement precision is achieved when multiple lidar systems make wind measurements at one point in space, while highest spatial coverage is achieved through using single lidar scanning measurements and using complex retrieval techniques.
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
Short summary
Short summary
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.
Clara M. St. Martin, Julie K. Lundquist, Andrew Clifton, Gregory S. Poulos, and Scott J. Schreck
Wind Energ. Sci., 1, 221–236, https://doi.org/10.5194/wes-1-221-2016, https://doi.org/10.5194/wes-1-221-2016, 2016
Short summary
Short summary
We use turbine nacelle-based measurements and measurements from an upwind tower to calculate wind turbine power curves and predict the production of energy. We explore how different atmospheric parameters impact these power curves and energy production estimates. Results show statistically significant differences between power curves and production estimates calculated with turbulence and stability filters, and we suggest implementing an additional step in analyzing power performance data.
Nicola Bodini, Julie K. Lundquist, Dino Zardi, and Mark Handschy
Wind Energ. Sci., 1, 115–128, https://doi.org/10.5194/wes-1-115-2016, https://doi.org/10.5194/wes-1-115-2016, 2016
Short summary
Short summary
Year-to-year variability of wind speeds limits the certainty of wind-plant preconstruction energy estimates ("resource assessments"). Using 62-year records from 60 stations across Canada we show that resource highs and lows persist for decades, which makes estimates 2–3 times less certain than if annual levels were uncorrelated. Comparing chronological data records with randomly permuted versions of the same data reveals this in an unambiguous and easy-to-understand way.
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
Short summary
Short summary
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.
J. K. Lundquist, M. J. Churchfield, S. Lee, and A. Clifton
Atmos. Meas. Tech., 8, 907–920, https://doi.org/10.5194/amt-8-907-2015, https://doi.org/10.5194/amt-8-907-2015, 2015
Short summary
Short summary
Wind-profiling lidars are now regularly used in boundary-layer meteorology and in applications like wind energy, but their use often relies on assuming homogeneity in the wind. Using numerical simulations of stable flow past a wind turbine, we quantify the error expected because of the inhomogeneity of the flow. Large errors (30%) in winds are found near the wind turbine, but by three rotor diameters downwind, errors in the horizontal components have decreased to 15% of the inflow.
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
Short summary
Short summary
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: Dynamics | Research Activity: Remote Sensing | Altitude Range: Mesosphere | Science Focus: Physics (physical properties and processes)
Winter 2018 major sudden stratospheric warming impact on midlatitude mesosphere from microwave radiometer measurements
Climatology of the mesopause relative density using a global distribution of meteor radars
Observations of OH airglow from ground, aircraft, and satellite: investigation of wave-like structures before a minor stratospheric warming
Mesospheric semidiurnal tides and near-12 h waves through jointly analyzing observations of five specular meteor radars from three longitudinal sectors at boreal midlatitudes
Statistical climatology of mid-latitude mesospheric summer echoes characterised by OSWIN (Ostsee-Wind) radar observations
Can VHF radars at polar latitudes measure mean vertical winds in the presence of PMSE?
The global climatology of the intensity of the ionospheric sporadic E layer
Long-term lidar observations of the gravity wave activity near the mesopause at Arecibo
Solar 27-day signatures in standard phase height measurements above central Europe
The MATS Satellite Mission – Gravity Waves Studies by Mesospheric Airglow/Aerosol Tomography and Spectroscopy
Mesospheric bores at southern midlatitudes observed by ISS-IMAP/VISI: a first report of an undulating wave front
Simultaneous observations of NLCs and MSEs at midlatitudes: implications for formation and advection of ice particles
Long-term observation of midlatitude quasi 2-day waves by a water vapor radiometer
Climatology of mesopause region nocturnal temperature, zonal wind and sodium density observed by sodium lidar over Hefei, China (32° N, 117° E)
Multi-static spatial and angular studies of polar mesospheric summer echoes combining MAARSY and KAIRA
Observation of Kelvin–Helmholtz instabilities and gravity waves in the summer mesopause above Andenes in Northern Norway
Temporal variability of tidal and gravity waves during a record long 10-day continuous lidar sounding
Quasi 18 h wave activity in ground-based observed mesospheric H2O over Bern, Switzerland
Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidar
Short-period mesospheric gravity waves and their sources at the South Pole
Long-term dynamics of OH * temperatures over central Europe: trends and solar correlations
MIPAS observations of longitudinal oscillations in the mesosphere and the lower thermosphere: climatology of odd-parity daily frequency modes
Neutral atmosphere temperature trends and variability at 90 km, 70 °N, 19 °E, 2003–2014
Response of OH airglow emissions to mesospheric gravity waves and comparisons with full-wave model simulation at a low-latitude Indian station
First continuous ground-based observations of long period oscillations in the vertically resolved wind field of the stratosphere and mesosphere
Semi-annual oscillation (SAO) of the nighttime ionospheric D region as detected through ground-based VLF receivers
Meteor radar quasi 2-day wave observations over 10 years at Collm (51.3° N, 13.0° E)
Observations of planetary waves in the mesosphere-lower thermosphere during stratospheric warming events
Evidence for tropospheric wind shear excitation of high-phase-speed gravity waves reaching the mesosphere using the ray-tracing technique
The quasi 16-day wave in mesospheric water vapor during boreal winter 2011/2012
Quantification of waves in lidar observations of noctilucent clouds at scales from seconds to minutes
Mean winds in the MLT, the SQBO and MSAO over Ascension Island (8° S, 14° W)
The diurnal and semidiurnal tides over Ascension Island (° S, 14° W) and their interaction with the stratospheric quasi-biennial oscillation: studies with meteor radar, eCMAM and WACCM
The roles of vertical advection and eddy diffusion in the equatorial mesospheric semi-annual oscillation (MSAO)
Transport of mesospheric H2O during and after the stratospheric sudden warming of January 2010: observation and simulation
First detection of tidal behaviour in polar mesospheric water vapour by ground based microwave spectroscopy
The climatology, propagation and excitation of ultra-fast Kelvin waves as observed by meteor radar, Aura MLS, TRMM and in the Kyushu-GCM
Mean winds, temperatures and the 16- and 5-day planetary waves in the mesosphere and lower thermosphere over Bear Lake Observatory (42° N, 111° W)
Aura MLS observations of the westward-propagating s=1, 16-day planetary wave in the stratosphere, mesosphere and lower thermosphere
Dynamics of the Antarctic and Arctic mesosphere and lower thermosphere – Part 1: Mean winds
Study on the impact of sudden stratosphere warming in the upper mesosphere-lower thermosphere regions using satellite and HF radar measurements
The 16-day wave in the Arctic and Antarctic mesosphere and lower thermosphere
Correlations of mesospheric winds with subtle motion of the Arctic polar vortex
The two-day wave in the Antarctic and Arctic mesosphere and lower thermosphere
Yuke Wang, Valerii Shulga, Gennadi Milinevsky, Aleksey Patoka, Oleksandr Evtushevsky, Andrew Klekociuk, Wei Han, Asen Grytsai, Dmitry Shulga, Valery Myshenko, and Oleksandr Antyufeyev
Atmos. Chem. Phys., 19, 10303–10317, https://doi.org/10.5194/acp-19-10303-2019, https://doi.org/10.5194/acp-19-10303-2019, 2019
Short summary
Short summary
The major sudden stratospheric warming (SSW) dramatically changed atmospheric conditions. This event is accompanied by a sharp increase in the polar stratosphere temperature, zonal wind reverse, and strong changes in the polar mesosphere. These changes affect even the midlatitude mesosphere, which is not widely covered by observations. Our newly installed microwave radiometer allowed for studying mesospheric zonal wind and CO variations to understand the SSW 2018 effects at midlatitudes.
Wen Yi, Xianghui Xue, Iain M. Reid, Damian J. Murphy, Chris M. Hall, Masaki Tsutsumi, Baiqi Ning, Guozhu Li, Robert A. Vincent, Jinsong Chen, Jianfei Wu, Tingdi Chen, and Xiankang Dou
Atmos. Chem. Phys., 19, 7567–7581, https://doi.org/10.5194/acp-19-7567-2019, https://doi.org/10.5194/acp-19-7567-2019, 2019
Short summary
Short summary
The seasonal variations in the mesopause densities, especially with regard to its global structure, are still unclear. In this study, we report the climatology of the mesopause density estimated using multiyear observations from nine meteor radars from Arctic to Antarctic latitudes. The results reveal a significant AO and SAO in mesopause density, an asymmetry between the two polar regions and evidence of intraseasonal oscillations (ISOs), perhaps associated with the ISOs of the troposphere.
Sabine Wüst, Carsten Schmidt, Patrick Hannawald, Michael Bittner, Martin G. Mlynczak, and James M. Russell III
Atmos. Chem. Phys., 19, 6401–6418, https://doi.org/10.5194/acp-19-6401-2019, https://doi.org/10.5194/acp-19-6401-2019, 2019
Short summary
Short summary
In winter 2016, the camera system FAIM derived information about the OH* airglow at ca. 86 km height during six flights on board the research aircraft FALCON in northern Scandinavia. Coincident ground- and satellite-based measurements (GRIPS and TIMED-SABER) complete the data set. The data are analysed with respect to the temporal and spatial evolution of small-scale atmospheric dynamics just before a minor stratospheric warming. Special emphasis is placed on possible instability features.
Maosheng He and Jorge Luis Chau
Atmos. Chem. Phys., 19, 5993–6006, https://doi.org/10.5194/acp-19-5993-2019, https://doi.org/10.5194/acp-19-5993-2019, 2019
Short summary
Short summary
We propose an approach to resolve waves with multiple spatial scales at a given frequency using ground-based detectors from few longitudinal sectors. The approach is used to investigate near-12 h waves. Results suggest that broadly reported enhancements of two solar nonmigrating tides during sudden stratospheric warming events are just low-frequency-resolved signatures of two neighboring waves. The tides do not enhance.
Dimitry Pokhotelov, Gunter Stober, and Jorge Luis Chau
Atmos. Chem. Phys., 19, 5251–5258, https://doi.org/10.5194/acp-19-5251-2019, https://doi.org/10.5194/acp-19-5251-2019, 2019
Short summary
Short summary
Twelve years of radar observations from a mid-latitude location in Kühlungsborn, Germany have been analysed to study characteristics of mesospheric summer echoes (MSEs). The statistical analysis shows that MSEs have a strong daytime preference and early summer seasonal preference. It is demonstrated that the meridional wind transport from polar regions is the important controlling factor for MSEs, while no clear connection to geomagnetic and solar activity is found.
Nikoloz Gudadze, Gunter Stober, and Jorge L. Chau
Atmos. Chem. Phys., 19, 4485–4497, https://doi.org/10.5194/acp-19-4485-2019, https://doi.org/10.5194/acp-19-4485-2019, 2019
Short summary
Short summary
We show a possibility of measuring mean vertical winds during the summer months using polar mesosphere summer echo (PMSE) observations. Middle Atmosphere Alomar Radar System observations of PMSE five-beam radial velocities are analysed to obtain the results. We found that sampling issues are the reason for bias in vertical wind measurements at the edges of PMSE altitudes. However, the PMSE is a good tracer for the mean vertical wind estimation at the central altitudes with its peak occurrence.
Bingkun Yu, Xianghui Xue, Xin'an Yue, Chengyun Yang, Chao Yu, Xiankang Dou, Baiqi Ning, and Lianhuan Hu
Atmos. Chem. Phys., 19, 4139–4151, https://doi.org/10.5194/acp-19-4139-2019, https://doi.org/10.5194/acp-19-4139-2019, 2019
Short summary
Short summary
It reports the long-term climatology of the intensity of Es layers from COSMIC satellites. The global Es maps present high-resolution spatial distributions and seasonal dependence. It mainly occurs at mid-latitudes and polar regions. Based on wind shear theory, simulation results indicate the convergence of vertical ion velocity could partially explain the Es seasonal dependence and some disagreements between observations and simulations suggest other processes play roles in the Es variations.
Xianchang Yue, Jonathan S. Friedman, Qihou Zhou, Xiongbin Wu, and Jens Lautenbach
Atmos. Chem. Phys., 19, 3207–3221, https://doi.org/10.5194/acp-19-3207-2019, https://doi.org/10.5194/acp-19-3207-2019, 2019
Short summary
Short summary
Using 11 years of lidar temperature data, the seasonal variations (SVs) of gravity waves (GWs) are addressed in the tropical mesopause region, shown to be clearly associated with the SVs of zonal winds reported in the literature. The SVs of GWs are determined by the filtering effect of the local background wind. The altitudes of GW potential energy have a close relation to the upper mesospheric temperature inversion layers (TILs), which provides support for the formation mechanism of TILs.
Christian von Savigny, Dieter H. W. Peters, and Günter Entzian
Atmos. Chem. Phys., 19, 2079–2093, https://doi.org/10.5194/acp-19-2079-2019, https://doi.org/10.5194/acp-19-2079-2019, 2019
Short summary
Short summary
This study investigates solar effects in radio reflection height observations in the ionospheric D region at an altitude of about 80 km at northern midlatitudes. The analyzed time series covers almost six solar cycles. Statistically significant solar 27-day and 11-year signatures are identified. However, the driving mechanisms are not fully understood. We also provide evidence for dynamical effects on the radio reflection heights with periods close to the solar rotational cycle.
Jörg Gumbel, Linda Megner, Ole Martin Christensen, Seunghyuk Chang, Joachim Dillner, Terese Ekebrand, Gabriel Giono, Arvid Hammar, Jonas Hedin, Nickolay Ivchenko, Bodil Karlsson, Mikael Kruse, Anqi Li, Steven McCallion, Donal P. Murtagh, Georgi Olentšenko, Soojong Pak, Woojin Park, Jordan Rouse, Jacek Stegman, and Georg Witt
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2018-1162, https://doi.org/10.5194/acp-2018-1162, 2018
Revised manuscript accepted for ACP
Short summary
Short summary
Atmospheric waves are important as they can link together conditions over large distances. MATS is a new Swedish satellite to be launched in 2019 that will study waves at altitudes around 80–110 km. MATS will take images of emissions from excited molecules, so-called airglow, and of the highest clouds in our atmosphere, so-called noctilucent clouds. These measurements will be analysed to provide three-dimensional wave structures, and these can then be related to other atmospheric altitudes.
Yuta Hozumi, Akinori Saito, Takeshi Sakanoi, Atsushi Yamazaki, and Keisuke Hosokawa
Atmos. Chem. Phys., 18, 16399–16407, https://doi.org/10.5194/acp-18-16399-2018, https://doi.org/10.5194/acp-18-16399-2018, 2018
Short summary
Short summary
Spatial structures of wave disturbances in the upper atmosphere were investigated with space-borne imaging from the International Space Station. The wave disturbance occurred around an altitude of 100 km, and is called a mesospheric bore. The large-scale structure of mesospheric bores has not been fully captured by previous ground-based imagers, but the space-borne imaging captured a bore with a wide field of view, and showed that bores can have a large undulating wave front as long as 2000 km.
Michael Gerding, Jochen Zöllner, Marius Zecha, Kathrin Baumgarten, Josef Höffner, Gunter Stober, and Franz-Josef Lübken
Atmos. Chem. Phys., 18, 15569–15580, https://doi.org/10.5194/acp-18-15569-2018, https://doi.org/10.5194/acp-18-15569-2018, 2018
Short summary
Short summary
We describe the first comparative study of noctilucent clouds (NLCs) and mesospheric summer echoes at midlatitudes. Therefore, this study compares fresh clouds (small particles) with fully evolved clouds in the mesosphere, hinting at their evolution. It is shown that, in contrast to higher latitudes, here only a thin layer of fresh particles exist above the NLCs. This gives evidence that NLCs are not formed locally but are typically advected. This needs to be acknowledged in trend studies.
Martin Lainer, Klemens Hocke, and Niklaus Kämpfer
Atmos. Chem. Phys., 18, 12061–12074, https://doi.org/10.5194/acp-18-12061-2018, https://doi.org/10.5194/acp-18-12061-2018, 2018
Short summary
Short summary
A long continuous record (in total 7 years) of middle atmospheric water vapor at the midlatitude NDACC station in Bern is investigated to study quasi 2-day wave oscillations (Q2DWs). We present monthly climatologies of the wave amplitudes and show the periods that the Q2DWs developed. What we observe is very-high-frequency variability. An autobicoherence analysis revealed nonlinear phase couplings between Q2DWs and other atmospheric waves. Our results are useful for model validation purposes.
Tao Li, Chao Ban, Xin Fang, Jing Li, Zhaopeng Wu, Wuhu Feng, John M. C. Plane, Jiangang Xiong, Daniel R. Marsh, Michael J. Mills, and Xiankang Dou
Atmos. Chem. Phys., 18, 11683–11695, https://doi.org/10.5194/acp-18-11683-2018, https://doi.org/10.5194/acp-18-11683-2018, 2018
Short summary
Short summary
A total of 154 nights of observations by the USTC Na temperature and wind lidar (32° N, 117° E) suggest significant seasonal variability in the mesopause. Chemistry plays an important role in Na atom formation. More than half of the observed gravity wave (GW) momentum flux (MF), whose divergence determines the GW forcing, is induced by short-period (10 min–2 h) waves. The anticorrelation between MF and zonal wind (U) suggests strong filtering of short-period GWs by semiannual oscillation U.
Jorge L. Chau, Derek McKay, Juha P. Vierinen, Cesar La Hoz, Thomas Ulich, Markku Lehtinen, and Ralph Latteck
Atmos. Chem. Phys., 18, 9547–9560, https://doi.org/10.5194/acp-18-9547-2018, https://doi.org/10.5194/acp-18-9547-2018, 2018
Short summary
Short summary
Combining a phased-array power radar and a phased-array radio telescope, we have been able to identify and characterized horizontal structures and movement of noctilucent clouds, but at 3 m scales instead of optical scales. As a byproduct of our observations, we have studied their angular dependence. We show a new alternative to study these clouds on routine basis and therefore study the atmospheric dynamics that modulate them.
Gunter Stober, Svenja Sommer, Carsten Schult, Ralph Latteck, and Jorge L. Chau
Atmos. Chem. Phys., 18, 6721–6732, https://doi.org/10.5194/acp-18-6721-2018, https://doi.org/10.5194/acp-18-6721-2018, 2018
Kathrin Baumgarten, Michael Gerding, Gerd Baumgarten, and Franz-Josef Lübken
Atmos. Chem. Phys., 18, 371–384, https://doi.org/10.5194/acp-18-371-2018, https://doi.org/10.5194/acp-18-371-2018, 2018
Short summary
Short summary
Gravity waves (GWs) as well as solar tides are a key driving mechanism for the circulation in the Earth's atmosphere. The temporal variation of these waves is studied using a record long 10-day continuous Rayleigh–Mie–Raman lidar sounding at midlatitudes. This data set shows a large variability of these waves on timescales of a few days and therefore provides new insights into wave intermittency phenomena, which can help to improve model simulations.
Martin Lainer, Klemens Hocke, Rolf Rüfenacht, and Niklaus Kämpfer
Atmos. Chem. Phys., 17, 14905–14917, https://doi.org/10.5194/acp-17-14905-2017, https://doi.org/10.5194/acp-17-14905-2017, 2017
Short summary
Short summary
We report on middle-atmospheric water vapor measurements above Bern from the ground-based microwave radiometer MIAWARA (NDACC affiliated) during two winter periods of 6 months. Quasi 18 h oscillations of mesospheric water vapor above 0.1 hPa are observed. Further, the 18 h wave is seen in a zonal wind data set from the Doppler wind radiometer WIRA. Inertia-gravity-wave-induced fluctuations or a nonlinear coupling between tides and quasi 2-day waves are considered as possible drivers.
Jens Hildebrand, Gerd Baumgarten, Jens Fiedler, and Franz-Josef Lübken
Atmos. Chem. Phys., 17, 13345–13359, https://doi.org/10.5194/acp-17-13345-2017, https://doi.org/10.5194/acp-17-13345-2017, 2017
Short summary
Short summary
We present altitude profiles of winds and temperatures in the Arctic strato- and mesosphere obtained during three Januaries. The data show large year-to-year variations. We compare the observations to model data. For monthly mean profiles we find good agreement below 55 km altitude but also differences of up to 20 K and 20 m s-1 above. The fluctuations during single nights indicate gravity waves. The kinetic energy of such waves is typically 5 to 10 times larger than their potential energy.
Dhvanit Mehta, Andrew J. Gerrard, Yusuke Ebihara, Allan T. Weatherwax, and Louis J. Lanzerotti
Atmos. Chem. Phys., 17, 911–919, https://doi.org/10.5194/acp-17-911-2017, https://doi.org/10.5194/acp-17-911-2017, 2017
Short summary
Short summary
This paper presents an investigation into the sources of atmospheric gravity waves observed at 90 km above Amundsen-Scott South Pole Station, Antarctica. By combining gravity wave characteristics obtained from imager data and a numerical model for 3-D wave propagation through the atmosphere, we find that the development of baroclinic instabilities via displacement of the polar vortex is a significant and unique source of vertically propagating, short-period (< 1 h) gravity waves in the region.
Christoph Kalicinsky, Peter Knieling, Ralf Koppmann, Dirk Offermann, Wolfgang Steinbrecht, and Johannes Wintel
Atmos. Chem. Phys., 16, 15033–15047, https://doi.org/10.5194/acp-16-15033-2016, https://doi.org/10.5194/acp-16-15033-2016, 2016
Short summary
Short summary
The analysis of temperatures in the mesopause region between 1988 to 2015 shows, besides the known correlation with the 11-year solar activity cycle, a trend reversal in 2008 that can be described by a long-term oscillation. Understanding such long periodic oscillations in the atmosphere is of prime importance for climate modelling and predictions of future trends.
Maya García-Comas, Francisco González-Galindo, Bernd Funke, Angela Gardini, Aythami Jurado-Navarro, Manuel López-Puertas, and William E. Ward
Atmos. Chem. Phys., 16, 11019–11041, https://doi.org/10.5194/acp-16-11019-2016, https://doi.org/10.5194/acp-16-11019-2016, 2016
Short summary
Short summary
In this paper, for the first time, temperature longitudinal oscillations are derived from 20 to 150 km from a single instrument. A climatology of amplitudes and phases of zonal waves with odd daily frequencies is presented on a global scale. The interannual variability in amplitudes of the migrating modes shows a QBO in the MLT, which is probably originated in the stratosphere. The results are useful for testing general circulation models considering tidal effects in the MLT region.
Silje Eriksen Holmen, Chris M. Hall, and Masaki Tsutsumi
Atmos. Chem. Phys., 16, 7853–7866, https://doi.org/10.5194/acp-16-7853-2016, https://doi.org/10.5194/acp-16-7853-2016, 2016
Short summary
Short summary
Atmospheric temperatures at 90 km height above Tromsø, Norway, from 2003 to 2014 have been determined using meteor radar. Periodic oscillations ranging from ~ 9 days to a year were found in the dataset, which were related to the large-scale circulation in the middle atmosphere and with wave activity. A trend analysis was performed, revealing an overall weak cooling trend from 2003 to 2014, which is in line with other recent studies on mesopause region (~ 90 km) temperature trends.
Rupesh N. Ghodpage, Michael P. Hickey, Alok K. Taori, Devendraa Siingh, and Parashram T. Patil
Atmos. Chem. Phys., 16, 5611–5621, https://doi.org/10.5194/acp-16-5611-2016, https://doi.org/10.5194/acp-16-5611-2016, 2016
Short summary
Short summary
Gravity-wave-induced oscillations have been characterized over Kolhapur (16.8°N and 74.2°E), India, using the adiabatic variations in OH airglow intensity and temperature data. The results show that there exist large deviations from one investigation to the other. We also use a full-wave model to simulate the response of OH emission to the wave motion and compare the results with observed values. This report discusses the observed wave characteristics and cause of the noted difference.
Rolf Rüfenacht, Klemens Hocke, and Niklaus Kämpfer
Atmos. Chem. Phys., 16, 4915–4925, https://doi.org/10.5194/acp-16-4915-2016, https://doi.org/10.5194/acp-16-4915-2016, 2016
Short summary
Short summary
We quantitatively analyze oscillations with periods from 5 to 50 days in horizontal wind profiles between mid-stratosphere and mesopause based on more than 44 months of data from high, mid- and low latitudes measured by a novel instrument. For the first time, long time series of continuous wind measurements allow direct observations of dynamics throughout this altitude range. The observations agree remarkably well with the ECMWF model in the stratosphere but discrepancies exist in the mesosphere.
Israel Silber, Colin Price, and Craig J. Rodger
Atmos. Chem. Phys., 16, 3279–3288, https://doi.org/10.5194/acp-16-3279-2016, https://doi.org/10.5194/acp-16-3279-2016, 2016
Short summary
Short summary
We report for the first time that the semi-annual oscillation (SAO) is one of the dominant oscillations in the nighttime lower ionosphere, using ground-based measurements of VLF signals reflected off the lower part of the ionosphere. We conclude that the origins of this oscillation are oscillatory changes of the D region's electrical characteristics, driven by NOx transport from the lower thermosphere. This oscillation should be considered in lower ionospheric and VLF wave propagation models.
F. Lilienthal and Ch. Jacobi
Atmos. Chem. Phys., 15, 9917–9927, https://doi.org/10.5194/acp-15-9917-2015, https://doi.org/10.5194/acp-15-9917-2015, 2015
Short summary
Short summary
The quasi 2-day wave (QTDW), one of the most striking features in the mesosphere/lower thermosphere, is analyzed using meteor radar measurements at Collm (51°N, 13°E) during 2004-2014. The QTDW has periods lasting between 43 and 52h during strong summer bursts, and weaker enhancements are found during winter. A correlation between QTDW amplitudes and wind shear suggests baroclinic instability to be a likely forcing mechanism.
N. H. Stray, Y. J. Orsolini, P. J. Espy, V. Limpasuvan, and R. E. Hibbins
Atmos. Chem. Phys., 15, 4997–5005, https://doi.org/10.5194/acp-15-4997-2015, https://doi.org/10.5194/acp-15-4997-2015, 2015
Short summary
Short summary
Planetary wave activity measured in the mesosphere to lower thermosphere is shown to increase drastically after strong stratospheric polar cap wind reversals associated with sudden stratospheric warmings. In addition, a moderate but significant correlation was found between planetary wave enhancement in the mesosphere to lower thermosphere and all stratospheric polar cap wind reversals, irrespective of the strength of the reversal.
M. Pramitha, M. Venkat Ratnam, A. Taori, B. V. Krishna Murthy, D. Pallamraju, and S. Vijaya Bhaskar Rao
Atmos. Chem. Phys., 15, 2709–2721, https://doi.org/10.5194/acp-15-2709-2015, https://doi.org/10.5194/acp-15-2709-2015, 2015
Short summary
Short summary
Sources and propagation characteristics of high-frequency gravity waves observed in the mesosphere using airglow emissions from Gadanki and Hyderabad, India, are investigated using reverse ray tracing. Wave amplitudes are also traced back, including both radiative and diffusive damping. Interestingly, large vertical shears in the horizontal wind are noticed near the ray terminal points (at 10-12km altitude) and are thus identified to be the source for generating the observed gravity waves.
D. Scheiben, B. Tschanz, K. Hocke, N. Kämpfer, S. Ka, and J. J. Oh
Atmos. Chem. Phys., 14, 6511–6522, https://doi.org/10.5194/acp-14-6511-2014, https://doi.org/10.5194/acp-14-6511-2014, 2014
N. Kaifler, G. Baumgarten, J. Fiedler, and F.-J. Lübken
Atmos. Chem. Phys., 13, 11757–11768, https://doi.org/10.5194/acp-13-11757-2013, https://doi.org/10.5194/acp-13-11757-2013, 2013
K. A. Day and N. J. Mitchell
Atmos. Chem. Phys., 13, 9515–9523, https://doi.org/10.5194/acp-13-9515-2013, https://doi.org/10.5194/acp-13-9515-2013, 2013
R. N. Davis, J. Du, A. K. Smith, W. E. Ward, and N. J. Mitchell
Atmos. Chem. Phys., 13, 9543–9564, https://doi.org/10.5194/acp-13-9543-2013, https://doi.org/10.5194/acp-13-9543-2013, 2013
R. L. Gattinger, E. Kyrölä, C. D. Boone, W. F. J. Evans, K. A. Walker, I. C. McDade, P. F. Bernath, and E. J. Llewellyn
Atmos. Chem. Phys., 13, 7813–7824, https://doi.org/10.5194/acp-13-7813-2013, https://doi.org/10.5194/acp-13-7813-2013, 2013
C. Straub, B. Tschanz, K. Hocke, N. Kämpfer, and A. K. Smith
Atmos. Chem. Phys., 12, 5413–5427, https://doi.org/10.5194/acp-12-5413-2012, https://doi.org/10.5194/acp-12-5413-2012, 2012
K. Hallgren and P. Hartogh
Atmos. Chem. Phys., 12, 3753–3759, https://doi.org/10.5194/acp-12-3753-2012, https://doi.org/10.5194/acp-12-3753-2012, 2012
R. N. Davis, Y.-W. Chen, S. Miyahara, and N. J. Mitchell
Atmos. Chem. Phys., 12, 1865–1879, https://doi.org/10.5194/acp-12-1865-2012, https://doi.org/10.5194/acp-12-1865-2012, 2012
K. A. Day, M. J. Taylor, and N. J. Mitchell
Atmos. Chem. Phys., 12, 1571–1585, https://doi.org/10.5194/acp-12-1571-2012, https://doi.org/10.5194/acp-12-1571-2012, 2012
K. A. Day, R. E. Hibbins, and N. J. Mitchell
Atmos. Chem. Phys., 11, 4149–4161, https://doi.org/10.5194/acp-11-4149-2011, https://doi.org/10.5194/acp-11-4149-2011, 2011
D. J. Sandford, C. L. Beldon, R. E. Hibbins, and N. J. Mitchell
Atmos. Chem. Phys., 10, 10273–10289, https://doi.org/10.5194/acp-10-10273-2010, https://doi.org/10.5194/acp-10-10273-2010, 2010
N. Mbatha, V. Sivakumar, S. B. Malinga, H. Bencherif, and S. R. Pillay
Atmos. Chem. Phys., 10, 3397–3404, https://doi.org/10.5194/acp-10-3397-2010, https://doi.org/10.5194/acp-10-3397-2010, 2010
K. A. Day and N. J. Mitchell
Atmos. Chem. Phys., 10, 1461–1472, https://doi.org/10.5194/acp-10-1461-2010, https://doi.org/10.5194/acp-10-1461-2010, 2010
Y. Bhattacharya and A. J. Gerrard
Atmos. Chem. Phys., 10, 431–436, https://doi.org/10.5194/acp-10-431-2010, https://doi.org/10.5194/acp-10-431-2010, 2010
V. M. Tunbridge and N. J. Mitchell
Atmos. Chem. Phys., 9, 6377–6388, https://doi.org/10.5194/acp-9-6377-2009, https://doi.org/10.5194/acp-9-6377-2009, 2009
Cited articles
Aitken, M. L., Banta, R. M., Pichugina, Y. L., and Lundquist, J. K.:
Quantifying Wind Turbine Wake Characteristics from Scanning
Remote Sensor Data, J. Atmos. Ocean. Tech., 31,
765–787, https://doi.org/10.1175/JTECH-D-13-00104.1, 2014. a
Berg, J., Troldborg, N., Menke, R., Patton, E. G., Sullivan, P. P., Mann, J., and Sørensen,
N. N.: Flow in complex terrain – a Large Eddy Simulation comparison study, Journal of
Physics: Conference Series, 1037, p072015, 2018. a
Burns, S. P., Sun, J., Lenschow, D. H., Oncley, S. P., Stephens, B. B., Yi, C.,
Anderson, D. E., Hu, J., and Monson, R. K.: Atmospheric Stability Effects
on Wind Fields and Scalar Mixing Within and Just Above a
Subalpine Forest in Sloping Terrain, Bound.-Lay. Meteorol., 138,
231–262, https://doi.org/10.1007/s10546-010-9560-6, 2011. a
Chow, F. K. and Street, R. L.: Evaluation of Turbulence Closure Models
for Large-Eddy Simulation over Complex Terrain: Flow over
Askervein Hill, J. Appl. Meteorol. Clim., 48,
1050–1065, https://doi.org/10.1175/2008JAMC1862.1, 2009. a
Earth Observing Laboratory: Perdigão data archive, available at:
http://data.eol.ucar.edu/master_list/?project=PERDIGAO, last access: 26 February 2019. a
Fernando, H., Mann, J., Palma, J., Lundquist, J., Barthelmie, R., BeloPereira,
M., Brown, W., Chow, F., Gerz, T., Hocut, C., Klein, P., Leo, L., Matos, J.,
Oncley, S., Pryor, S., Bariteau, L., Bell, T., Bodini, N., Carney, M.,
Courtney, M., Creegan, E., Dimitrova, R., Gomes, S., Hagen, M., Hyde, J.,
Kigle, S., Krishnamurthy, R., Lopes, J., Mazzaro, L., Neher, J., Menke, R.,
Murphy, P., Oswald, L., Otarola-Bustos, S., Pattantyus, A., Rodrigues, C. V.,
Schady, A., Sirin, N., Spuler, S., Svensson, E., Tomaszewski, J., Turner, D.,
van Veen, L., Vasiljević, N., Vassallo, D., Voss, S., Wildmann, N., and
Wang, Y.: The Perdigão: Peering into Microscale Details of
Mountain Winds, B. Am. Meteorol. Soc.,
online first, https://doi.org/10.1175/BAMS-D-17-0227.1, 2018. a
Finnigan, J. and Belcher, S.: Flow over a hill covered with a plant canopy,
Q. J. Roy. Meteor. Soc., 130, 1–29, 2004. a
Hunt, J. C. R. and Snyder, W. H.: Experiments on stably and neutrally
stratified flow over a model three-dimensional hill, J. Fluid
Mech., 96, 671–704, https://doi.org/10.1017/S0022112080002303, 1980. a
Iungo, G. V., Wu, Y.-T., and Porté-Agel, F.: Field Measurements of Wind
Turbine Wakes with Lidars, J. Atmos. Ocean.
Tech., 30, 274–287, https://doi.org/10.1175/JTECH-D-12-00051.1, 2013. a
Kaimal, J. C. and Finnigan, J. J.: Atmospheric boundary layer flows: their
structure and measurement, Oxford university press, 1994. a
Käsler, Y., Rahm, S., Simmet, R., and Kühn, M.: Wake Measurements of a
Multi-MW Wind Turbine with Coherent Long-Range Pulsed
Doppler Wind Lidar, J. Atmos. Ocean. Tech., 27,
1529–1532, https://doi.org/10.1175/2010JTECHA1483.1, 2010. a
Kutter, E., Yi, C., Hendrey, G., Liu, H., Eaton, T., and Ni-Meister, W.:
Recirculation over complex terrain: Recirculation Over Complex
Terrain, J. Geophys. Res.-Atmos., 122, 6637–6651,
https://doi.org/10.1002/2016JD026409, 2017. a, b, c
Lange, J., Mann, J., Angelou, N., Berg, J., Sjöholm, M., and Mikkelsen, T.:
Variations of the Wake Height over the Bolund Escarpment Measured
by a Scanning Lidar, Bound.-Lay. Meteorol., 159, 147–159,
https://doi.org/10.1007/s10546-015-0107-8, 2016. a
Lange, J., Mann, J., Berg, J., Parvu, D., Kilpatrick, R., Costache, A.,
Chowdhury, J., Siddiqui, K., and Hangan, H.: For wind turbines in complex
terrain, the devil is in the detail, Environ. Res. Lett., 12,
094020, https://doi.org/10.1088/1748-9326/aa81db, 2017. a
Mann, J., Angelou, N., Arnqvist, J., Callies, D., Cantero, E., Arroyo, R. C.,
Courtney, M., Cuxart, J., Dellwik, E., Gottschall, J., Ivanell, S., Kÿhn,
P., Lea, G., Matos, J. C., Palma, J. M. L. M., Pauscher, L., Peña, A.,
Rodrigo, J. S., Söderberg, S., Vasiljevic, N., and Rodrigues, C. V.: Complex
terrain experiments in the New European Wind Atlas, Philos.
T. Roy. Soc. A, 375, 2016101, https://doi.org/10.1098/rsta.2016.0101, 2017. a, b, c
Menke, R., Vasiljevic, N., Hansen, K., Hahmann, A. N., and Mann, J.: Does the
wind turbine wake follow the topography? – A multi-lidar study in complex
terrain, Wind Energ. Sci., 3, 681–691, https://doi.org/10.5194/wes-3-681-2018, 2018a. a
Menke, R., Mann, J., and Vasiljevic, N.: Perdigão-2017: multi-lidar flow mapping over the complex terrain site, https://doi.org/10.11583/DTU.7228544.v1, 2018b. a
Porto University: WindsP data archive, available at: https://windsp.fe.up.pt/, last access: 26 February
2019.
a
Rotach, M. W. and Zardi, D.: On the boundary-layer structure over highly
complex terrain: Key findings from MAP, Q. J. Roy.
Meteor. Soc., 133, 937–948, https://doi.org/10.1002/qj.71, 2007. a
Sathe, A., Mann, J., Barlas, T., Bierbooms, W., and van Bussel, G.: Influence
of atmospheric stability on wind turbine loads: Atmospheric stability and
loads, Wind Energy, 16, 1013–1032, https://doi.org/10.1002/we.1528, 2013. a
Silva Lopes, A., Palma, J. M. L. M., and Castro, F. A.: Simulation of the
Askervein flow. Part 2: Large-eddy simulations, Bound.-Lay.
Meteorol., 125, 85–108, https://doi.org/10.1007/s10546-007-9195-4, 2007. a
Sogachev, A., Rannik, Ü., and Vesala, T.: Flux footprints over complex
terrain covered by heterogeneous forest, Agr. Forest Meteorol.,
127, 143–158, https://doi.org/10.1016/j.agrformet.2004.07.010, 2004. a
Taylor, P. A. and Teunissen, H. W.: Askervein'82: Report on the
September/October 1982 Experiment to Study Boundary Layer Flow
over Askervein, South Uist, Meteorological Services Research Branch,
Atmospheric Environment Service, 1983. a
Troen, I. and Petersen, E. L.: European wind atlas, Published for the
Commission of the European Communities, Directorate-General for Science,
Research, and Development, Brussels, Belgium by Risø National Laboratory,
Roskilde, Denmark, 1989. a
Vasiljevic, N., Lea, G., Courtney, M., Cariou, J.-P., Mann, J., and Mikkelsen,
T.: Long-range WindScanner system, Remote Sensing, 8, 896, https://doi.org/10.3390/rs8110896, 2016. a
Vasiljević, N., L. M. Palma, J. M., Angelou, N., Carlos Matos, J., Menke, R., Lea, G., Mann, J., Courtney, M., Frölen
Ribeiro, L., and M. G. C. Gomes, V. M.: Perdigão 2015: methodology for atmospheric multi-Doppler lidar experiment
Atmos. Meas. Tech., 10, 3463–3483, https://doi.org/10.5194/amt-10-3463-2017, 2017. a, b
WASP: Wind Atlas Analysis and Application Program, available at: http://www.wasp.dk, last access: January 31
2019. a
Wood, N.: The onset of separation in neutral, turbulent flow over hills,
Bound.-Lay. Meteorol., 76, 137–164, https://doi.org/10.1007/BF00710894, 1995. a
Xu, X. and Yi, C.: The influence of geometry on recirculation and CO2
transport over forested hills, Meteorol. Atmos. Phys., 119,
187–196, https://doi.org/10.1007/s00703-012-0224-6, 2013. a
Search articles
Short summary
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.
This research utilizes several months of lidar measurements from the Perdigão 2017 campaign to...
Atmospheric Chemistry and Physics
An interactive open-access journal of the European Geosciences Union
