Artykuły w czasopismach na temat „Wind direction”
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1
Mahrt, Larry. "Surface Wind Direction Variability". Journal of Applied Meteorology and Climatology 50, nr 1 (1.01.2011): 144–52. http://dx.doi.org/10.1175/2010jamc2560.1.
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Abstract Common large shifts of wind direction in the weak-wind nocturnal boundary layer are poorly understood and are not adequately captured by numerical models and statistical parameterizations. The current study examines 15 datasets representing a variety of surface conditions to study the behavior of wind direction variability. In contrast to previous studies, the current investigation directly examines wind direction changes with emphasis on weak winds and wind direction changes over smaller time periods of minutes to tens of minutes, including large wind direction shifts. A formulation of the wind direction changes is offered that provides more realistic behavior for very weak winds and for complex terrain.
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Hisaki, Yukiharu. "Sea Surface Wind Correction Using HF Ocean Radar and Its Impact on Coastal Wave Prediction". Journal of Atmospheric and Oceanic Technology 34, nr 9 (wrzesień 2017): 2001–20. http://dx.doi.org/10.1175/jtech-d-16-0249.1.
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AbstractBoth wind speeds and wind directions are important for predicting wave heights near complex coastal areas, such as small islands, because the fetch is sensitive to the wind direction. High-frequency (HF) radar can be used to estimate sea surface wind directions from first-order scattering. A simple method is proposed to correct sea surface wind vectors from reanalysis data using the wind directions estimated from HF radar. The constraints for wind speed corrections are that the corrections are small and that the corrections of horizontal divergences are small. A simple algorithm for solving the solution that minimizes the weighted sum of the constraints is developed. Another simple method is proposed to correct sea surface wind vectors. The constraints of the method are that corrections of wind vectors and horizontal divergences from the reanalysis wind vectors are small and that the projection of the corrected wind vectors to the direction orthogonal to the HF radar–estimated wind direction is small. The impact of wind correction on wave parameter prediction is large in the area in which the fetch is sensitive to wind direction. The accuracy of the wave prediction is improved by correcting the wind in that area, where correction of wind direction is more important than correction of wind speeds for the improvement. This method could be used for near-real-time wave monitoring by correcting forecast winds using HF radar data.
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Boyce, Richard L. "Wind direction and fir wave motion". Canadian Journal of Forest Research 18, nr 4 (1.04.1988): 461–66. http://dx.doi.org/10.1139/x88-067.
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The direction of travel for each of 11 fir waves in the White Mountains of New Hampshire was determined from their positions on aerial photographs taken in 1978, 1966, and 1943–1944. The direction toward which trees within each wave were flagged was determined in the field and used to infer the direction of prevailing winds. Flagging and fir wave directions are found to be closely related. Most wave velocities fall within the range 1–3 m year−1, as found in earlier studies. Wave direction generally parallels the fall line, but in cases where the flagging direction crosses the fall line, the wave follows the flagging direction. The flagging observed in fir waves appears to be caused by rime ice damage. It indicates that a narrow range of mean annual wind velocities are present where waves occur. The close relationship between flagging and fir wave directions suggests that wind and rime ice buildup are important factors in advancing the dieback zone of fir waves.
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WEERASINGHE, R. M., A. S. PANNILA, M. K. JAYANANDA i D. U. J. SONNADARA. "MULTIFRACTAL BEHAVIOR OF WIND SPEED AND WIND DIRECTION". Fractals 24, nr 01 (marzec 2016): 1650003. http://dx.doi.org/10.1142/s0218348x16500031.
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In this paper, an analysis of temporal variation of wind speed and wind direction recorded at 10 min intervals are presented. The measurements were carried out at Hambanthota, a site located in the southern coastal belt of Sri Lanka which has a high potential for wind power generation. The multifractal detrended fluctuation analysis was used to analyze the temporal scaling properties of wind speeds and wind directions. The analysis was carried out for seasonal variation of wind speed and wind direction. It was observed that the scaling behavior of wind speed in Hambanthota is similar to the scaling behavior observed in previous studies which were carried out in other parts of the world. The seasonal wind and wind direction change exhibits different scaling behavior. No difference in scaling behavior was observed with heights. The degree of multifractality is high for wind direction when compared with wind speed for each season.
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Tai, Hui Xin, Yu Lan Yang i Fuying Liu. "The All-Wind-Direction Computer Simulation on the Outdoor Wind Environment". Advanced Materials Research 599 (listopad 2012): 202–5. http://dx.doi.org/10.4028/www.scientific.net/amr.599.202.
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This paper aims to investigate how the wind drection influence the outdoor wind environment. Fluent Airpak is used to simulate the wind environment of a residential area in Hangzhou city of China, the atmosphere boundary layer （ABL） is setted up as 16 wind direction with the mean velocity on each wind direction throughout the local typical year meteorological data. The simulation yield the data for the Maximum Wind Velocity (MWV) and the Amplification Factor (AF) Two main findings are:1)The MWV and AF vary greatly according to the wind direction setted up in ABL. 2)None of the wind directions which present to the maximum MWV and the maximum AF in the residential area is consistent with the wind direction with highest frequency in the local typical year meteorological data. Therefore, it is suggested that the outdoor wind simulation should be carried out by the all directions rather than the wind direction with the highest frequency.
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Sang, Le Quang, Takao Maeda i Yasunari Kamada. "Study effect of extreme wind direction change on 3-bladed horizontal axis wind turbine". International Journal of Renewable Energy Development 8, nr 3 (22.10.2019): 261–66. http://dx.doi.org/10.14710/ijred.8.3.261-266.
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The Horizontal Axis Wind Turbines (HAWT) are used very popular in the world. They were installed mainly on land. However, on the land, the wind regime change is very complex such as high turbulence and constantly changing wind direction. In the International Electrotechnical Commission (IEC) 61400-1 standard, the wind regime is devided into the normal wind conditions and the extreme wind conditions. This study will focus on the extreme wind direction change and estimate the aerodynamic forces acting on a 3-bladed HAWT under this condition. Because the extreme wind direction change may cause extreme loads and it will affect the lifetime of HAWTs. This issue is experimented in the wind tunnel in Mie University, Japan to understand these effects. The wind turbine model is the 3-bladed HAWT type and using Avistar airfoil for making blades. A 6-component balance is used to measure the forces and the moments acting on the entire wind turbine in the three directions of x, y and z-axes. This study estimates the load fluctuation of the 3-bladed wind turbine under extreme wind direction change. The results show that the yaw moment and the pitch moment under the extreme wind direction change fluctuate larger than the normal wind condition. Specifically, before the sudden wind direction change happened, the averaged maximum pitch moment MX is -1.78 Nm, and after that MX is 4.45 Nm at inrush azimuth of 0°.©2019. CBIORE-IJRED. All rights reserved
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Guo, Peng, Si Chen, Jingchun Chu i David Infield. "Wind direction fluctuation analysis for wind turbines". Renewable Energy 162 (grudzień 2020): 1026–35. http://dx.doi.org/10.1016/j.renene.2020.07.137.
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Lokoshchenko, M. A. "Wind direction in Moscow". Russian Meteorology and Hydrology 40, nr 10 (październik 2015): 639–46. http://dx.doi.org/10.3103/s1068373915100015.
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Brettle, M. J. "WIND DIRECTION AND GUSTS". Weather 45, nr 10 (październik 1990): 373–75. http://dx.doi.org/10.1002/j.1477-8696.1990.tb05557.x.
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Slizhе, M. O., A. B. Semergei-Chumachenko i El Hadri Youssef. "Current distribution of wind in Morocco". Ukrainian hydrometeorological journal, nr 17 (29.10.2017): 61–69. http://dx.doi.org/10.31481/uhmj.17.2016.07.
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Information about wind is widely used in many sectors of the economy. Wind also causes many dangerous and extreme weather events. Modern climate changes require a certain revision of weather patterns previously accepted for the area. This article provides information on the current space and time distribution of wind characteristics within the territory of Morocco. During the period of 2005-2014 some monthly average wind speed values and data on repeatability of wind directions by gradations were obtained on the basis of physical and statistical analysis of results of observations of wind speed and directions performed at 26 stations.
The authors defined the character of distribution of monthly averages of wind speed within the territory and its seasonal changes. Most of the territory is covered by mountains of Morocco which encourages development of local winds. At central and northern regions of Morocco predominance of weak winds due to complex orography of terrain is observed. In the central part of Morocco there is a region with the lowest values of wind speed. Formation of the wind regime at the coastal stations takes place in a developed breeze circulation. Wind speed and direction are significantly different at the nearby stations, such as Larache and Chefchaouen, Meknes and Fez.
Increase of wind during the warmer half of a year was revealed at all stations. Nature of annual variation of average wind speed at the stations allows us to split the stations into two groups. The first group includes the stations where the average wind speed increases in summer and decreases in winter. The second group includes the stations where the average wind speed increases in spring and decreases in autumn. In the southern part and along the coast, where the terrain is flat, an increase of wind speed is observed. On open plains of the southern part of Atlantic coast during all seasons wind has a direction corresponding to direction of trade winds of the Northern hemisphere. It should be noted that the main factor forming air circulation within the territory of Morocco is represented by trade winds the intensity of which nearly doubles from summer to winter.
Formation of wind directions at the stations takes place mainly under the influence of terrain of the area. At many stations predominant wind direction in January changes by 180º in comparison to the respective July values. Therefore, characteristics of the wind regime of Morocco in 2005-2014 consist in increase of wind speed in the coastal zone and decrease thereof in mountain areas together with presence of two types of annual variation of wind speed depending on physical and geographical conditions.
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Faig Bayramova, Ulker. "Wind analysis at Ganja International Airport". SCIENTIFIC WORK 61, nr 12 (25.12.2020): 162–65. http://dx.doi.org/10.36719/2663-4619/61/162-165.
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The article reviews wind conditions at Ganja International Airport and specifies the maximum winds observed during the month and the direction of the winds. The direction of the mean, maximum wind speed of the prevailing wind was analyzed. Based on our analysis, we can see that the prevailing wind direction isnortheast and the maximum speed was recorded in March. Key words: wind, temperature, aviation, wind rose, visibility
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Li, Fengjiao, Guoyi Jiang i Tingting Hu. "Coughing Intensity and Wind Direction Effects on the Transmission of Respiratory Droplets: A Computation with Euler–Lagrange Method". Atmosphere 13, nr 4 (7.04.2022): 594. http://dx.doi.org/10.3390/atmos13040594.
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Studies on droplet transmission are needed to understand the infection mechanism of SARS-CoV-2. This research investigated the effects of coughing intensity and wind direction on respiratory droplets transportation using the Euler–Lagrange method. The results revealed that both coughing intensity and wind conditions considerably influence the transmission of small and medium droplets but had little effect on large droplets. A stronger coughing intensity resulted in small and medium droplets traveling farther in a calm wind and spreading widely and rapidly in a windy environment. The droplets do not travel far in the absence of ambient wind, even with stronger coughing. Medium droplets spread in clusters, and small droplets drifted out of the domain in the band area in different wind conditions except for 60° and 90° wind directions, in which cases, the droplets were blown directly downstream. In 0° wind direction, many droplets were deposited on the human body. The fast and upward movement of particles in 60° and 90° directions could cause infection risk with short exposure. In 180° wind direction, droplets spread widely and traveled slowly because of the reverse flow downstream, prolonged exposure can result in a high risk of infection.
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Bentamy, A., D. Croize-Fillon i C. Perigaud. "Characterization of ASCAT measurements based on buoy and QuikSCAT wind vector observations". Ocean Science 4, nr 4 (11.12.2008): 265–74. http://dx.doi.org/10.5194/os-4-265-2008.
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Abstract. The new scatterometer Advanced SCATterometer (ASCAT) onboard MetOp-A satellite provides surface wind speed and direction over global ocean with a spatial resolution of 25 km square over two swaths of 550 km widths. The accuracy of ASCAT wind retrievals is determined through various comparisons with moored buoys. The comparisons indicate that the remotely sensed wind speeds and directions agree well with buoy data. The root-mean-squared differences of the wind speed and direction are less than 1.72 m/s and 18°, respectively. At global scale, ASCAT winds are compared with surface winds derived from QuikSCAT scatterometer. The results confirm the buoy analyses, especially for wind speed ranging between 3 m/s and 20 m/s. For higher wind conditions, ASCAT is biased low. The ASCAT underestimation with respect to QuikSCAT winds is wind speed dependent. The comparisons based on the collocated scatterometer data collected after 17 of October 2007 indicate that there are significant improvements compared to previous periods.
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Bentamy, A. "Characterization of ASCAT measurements based on buoy and QuikSCAT wind vector observations". Ocean Science Discussions 5, nr 1 (19.03.2008): 77–101. http://dx.doi.org/10.5194/osd-5-77-2008.
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Abstract. The new scatterometer Advanced SCATterometer (ASCAT) onboard MetOp-A satellite provides surface wind speed and direction over global ocean with a spatial resolution of 25 km square over two swaths of 550 km widths. The accuracy of ASCAT wind retrievals is determined through various comparisons with moored buoys. The comparisons indicate that the remotely sensed wind speeds and directions agree well with buoy data. The root-mean-squared differences of the wind speed and direction are less than 1.72 m/s and 18°, respectively. At global scale, ASCAT winds are compared with surface winds derived from QuikSCAT scatterometer. The results confirm the buoy analyses, especially for wind speed ranging between 3 m/s and 20 m/s. For higher wind conditions, ASCAT is biased low. The ASCAT underestimation with respect to QuikSCAT winds is wind speed dependent. The comparisons based on the collocated scatterometer data collected after 17 October 2007 indicate that there are significant improvements compared to previous periods.
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Holmes, J. D. "Wind climate of the Melbourne metropolitan area". Proceedings of the Royal Society of Victoria 133, nr 2 (2021): 82. http://dx.doi.org/10.1071/rs21011.
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This paper describes a probabilistic analysis of data recorded by the Bureau of Meteorology (BoM) for the wind climate of the Melbourne metropolitan area. It is based on 10-minute average wind data from four automatic weather stations (AWS) ‒ at Melbourne and Essendon airports, Fawkner Beacon in Port Phillip Bay, and Moorabbin Airport. Corrections to the data were made to adjust to standard terrain conditions and height. For the land stations, these were based on estimates of the surface roughness length at each site as a function of wind direction, making use of recorded gust factors. For the Fawkner Beacon, which is completely surrounded by open water, the surface roughness length is a function of mean wind speed, and the Charnock relationship was used in determining the corrections. For each station the terrain-corrected wind data were fitted with Weibull probability distributions, as an all-direction group and for sixteen direction sectors. Directional probabilities were also determined. The parameters of the all-direction Weibull distributions are very similar for all four stations, but there are differences in directional probabilities for some directions, with a geographic trend from north to south in the region being apparent. Some possible explanations based on the general topography are given.
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Zaini, S. S., N. Rossli, T. A. Majid, S. N. C. Deraman i N. A. Razak. "Wind Directional Effect on a Single Storey House Using Educational Wind Tunnel". MATEC Web of Conferences 206 (2018): 01006. http://dx.doi.org/10.1051/matecconf/201820601006.
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Wind tunnel testing of single-storey isolated building with 1: 100 scale down model was carried out in an open circuit wind tunnel without roughness elements facilities. The gable roof building model with 30˚ roof pitch was studied for wind directions of 0˚, 30˚, 45˚, 60˚ and 90˚. Pressure measurements were performed on all the walls and the roof (Zone 1, 2, 3, 4 and 5) of the building model with wind speed of 12 m/s. The results showed that the high suctions were generally induced by the 90˚ wind direction for Zone 1 and 60˚ and 90˚ wind directions for Zone 2. Mostly, high suction was also observed in case of 45˚ and 60˚ wind direction in Zone 3. In zone 4 and zone 5, high suction was generally induced by the 0˚ wind direction.
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Koch, W. "Directional analysis of SAR images aiming at wind direction". IEEE Transactions on Geoscience and Remote Sensing 42, nr 4 (kwiecień 2004): 702–10. http://dx.doi.org/10.1109/tgrs.2003.818811.
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Quanduo, Gao, i Gerbrand Komen. "Directional Response of Ocean Waves to Changing Wind Direction". Journal of Physical Oceanography 23, nr 7 (lipiec 1993): 1561–66. http://dx.doi.org/10.1175/1520-0485(1993)023<1561:droowt>2.0.co;2.
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Rascle, Nicolas, Bertrand Chapron, Aurélien Ponte, Fabrice Ardhuin i Patrice Klein. "Surface Roughness Imaging of Currents Shows Divergence and Strain in the Wind Direction". Journal of Physical Oceanography 44, nr 8 (1.08.2014): 2153–63. http://dx.doi.org/10.1175/jpo-d-13-0278.1.
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Abstract Images of sea surface roughness—for example, obtained by synthetic aperture radars (SAR) or by radiometers viewing areas in and around the sun glitter—at times provide clear observations of meso- and submesoscale oceanic features. Interacting with the surface wind waves, particular deformation properties of surface currents are responsible for those manifestations. Ignoring other sources of surface roughness variations, the authors limit their discussion to the mean square slope (mss) variability. This study confirms that vortical currents and currents with shear in the wind direction shall not be expressed in surface roughness images. Only divergent currents or currents with no divergence but strained in the wind direction can exhibit surface roughness signatures. More specifically, nondivergent currents might be traced with a 45° sensitivity to the wind direction. A simple method is proposed in order to interpret high-resolution roughness images, where roughness variations are proportional to ∂u/∂x + α∂υ/∂y, a linear combination of the along-wind and crosswind current gradients. The polarization parameter α depends upon the sensor look direction and the directional properties of the surface waves selected by the sensor. The use of multiple look directions or possible acquisitions with different wind directions shall thus help to retrieve surface currents from surface roughness observations.
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Van Vledder, G. Ph, i L. H. Holthuijsen. "WAVES IN TURNING WIND FIELDS". Coastal Engineering Proceedings 1, nr 21 (29.01.1988): 43. http://dx.doi.org/10.9753/icce.v21.43.
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A numerical model to compute to a high degree of accuracy nonlinear wave-wave interactions of wind generated waves supplemented with formulations of wind generation and white-capping, has been used to estimate qualitatively and quantitatively the effect of these physical processes on the directional response of waves in a turning wind field. After a sudden shift in wind direction the wave spectrum develops a secondary peak in the new wind direction. The initial peak of the spectrum either merges fairly quickly with this new peak or it slowly disappears, depending on the magnitude of the directional wind shift. The turning of the mean wave direction towards the new wind direction is caused by wind generation. The processes of nonlinear wave-wave interactions and white-capping tend to slow down the turning rate induced by the wind generation. The net turning rate of the mean wave direction in the model is twice as slow as in observations acquired in the central and southern North Sea.
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Liu, Wen Jian. "Safety Performance Evaluation of Wind Power Tower under Wind Load". Applied Mechanics and Materials 437 (październik 2013): 281–85. http://dx.doi.org/10.4028/www.scientific.net/amm.437.281.
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The 3d finite element model of wind power tower is established, and strain, displacement, bending moment and shearing forcing were calculated under different angle of wind blade and opening direction of wind power tower. Finally, the mechanical performance of wind power tower in different wind directions were analyzed with limited element method. The results show that the maximum strain appeared at the opening position under 180° between wind blade and opening direction, while the maximum strain value appeared at the upper position of the wind power tower under 0° and 90°. Shearing force and bending moment under 180° are greatest while shearing force and bending moment under 0° are the least. The force of wind power tower facing wind direction is greater than that 90°sidewind, and the strength design of wind power tower under 50 years design wind loads satisfies the requirement.
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Simiu, E., i N. A. Heckert. "Wind direction and hurricane-induced ultimate wind loads". Journal of Wind Engineering and Industrial Aerodynamics 74-76 (kwiecień 1998): 1037–46. http://dx.doi.org/10.1016/s0167-6105(98)00095-6.
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Soukissian, Takvor, i Maria-Aliki Sotiriou. "Long-Term Variability of Wind Speed and Direction in the Mediterranean Basin". Wind 2, nr 3 (28.07.2022): 513–34. http://dx.doi.org/10.3390/wind2030028.
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In this work, the ERA5 reanalysis dataset, with its fine spatial and temporal resolution, is used to study the wind speed and direction characteristics in the Mediterranean basin from 1979 to 2020. Their variability, trend and mean values, as well as their association, are examined in the monthly, annual and interannual/decadal time scales. The long-term variability of the wind direction is assessed using the angular variance, while the mean annual and interannual variability are used for the wind speed. The most characteristic and constant flow systems appear in the Gulf of Lion (Mistral) and the Aegean Sea during the summer (Etesian winds). The mean annual variability maximizes in the northern part of the basin, while the western part appears to have the most variable wind directions, while the fastest increasing wind speeds appear in the southwestern Levantine sub-basin. The long-term linear trend for the mean, the 95th and 99th quantiles of annual wind speed and the number of occurrences of extreme wind events have been also assessed. For particular areas, there is an increasing tendency in both intensity and frequency of occurrence of extreme wind events. Τhe linear-circular correlation coefficient has been implemented in order to quantify the linear association between the wind direction and the wind speed. This parameter demonstrates higher annual values for the Mistral wind in the Gulf of Lion and the Etesian winds in the Aegean Sea during the summer. Finally, the comparison of the results of ERA5 with the results of ERA-Interim highlighted significant differences in the Mediterranean wind speed and direction characteristics.
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Khalid, Mahmood. "Crosswise Wind Shear Represented as a Ramped Velocity Profile Impacting a Forward-Moving Aircraft". International Journal of Aerospace Engineering 2019 (18.08.2019): 1–18. http://dx.doi.org/10.1155/2019/7594737.
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Abrupt changes in wind velocities over small distances in a lateral or vertical direction can produce wind shear which is known to have serious effects upon the performance of an aircraft. Brought about by large-scale changes in the atmospheric conditions, it is a three-dimensional flow phenomenon imposing severe velocity gradients on an aircraft from all possible directions. While it would be difficult to model an instantaneous velocity gradient in a lateral plane, a vortical flow impinging from the sides which represents a wind shear in a vertical direction is imposed on a forward-moving aircraft to investigate the effect on the aerodynamic performance. The maximum shear wind speed from the side was fixed at 0.3 times the forward velocity. After due validations under no-wind shear conditions on simpler half-reflection plane models, a BGK airfoil-based full 3D wing and the ONERA M6 3D wing model were selected for preliminary studies. The investigation was concluded using the ARA M100 wing-fuselage model.
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Bessho, Kotaro, Mark DeMaria i John A. Knaff. "Tropical Cyclone Wind Retrievals from the Advanced Microwave Sounding Unit: Application to Surface Wind Analysis". Journal of Applied Meteorology and Climatology 45, nr 3 (1.03.2006): 399–415. http://dx.doi.org/10.1175/jam2352.1.
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Abstract Horizontal winds at 850 hPa from tropical cyclones retrieved using the nonlinear balance equation, where the mass field was determined from Advanced Microwave Sounding Unit (AMSU) temperature soundings, are compared with the surface wind fields derived from NASA's Quick Scatterometer (QuikSCAT) and Hurricane Research Division H*Wind analyses. It was found that the AMSU-derived wind speeds at 850 hPa have linear relations with the surface wind speeds from QuikSCAT or H*Wind. There are also characteristic biases of wind direction between AMSU and QuikSCAT or H*Wind. Using this information to adjust the speed and correct for the directional bias, a new algorithm was developed for estimation of the tropical cyclone surface wind field from the AMSU-derived 850-hPa winds. The algorithm was evaluated in two independent cases from Hurricanes Floyd (1999) and Michelle (2001), which were observed simultaneously by AMSU, QuikSCAT, and H*Wind. In this evaluation the AMSU adjustment algorithm for wind speed worked well. Results also showed that the bias correction algorithm for wind direction has room for improvement.
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Simley, Eric, Paul Fleming i Jennifer King. "Design and analysis of a wake steering controller with wind direction variability". Wind Energy Science 5, nr 2 (8.04.2020): 451–68. http://dx.doi.org/10.5194/wes-5-451-2020.
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Abstract. Wind farm control strategies are being developed to mitigate wake losses in wind farms, increasing energy production. Wake steering is a type of wind farm control in which a wind turbine's yaw position is misaligned from the wind direction, causing its wake to deflect away from downstream turbines. Current modeling tools used to optimize and estimate energy gains from wake steering are designed to represent wakes for fixed wind directions. However, wake steering controllers must operate in dynamic wind conditions and a turbine's yaw position cannot perfectly track changing wind directions. Research has been conducted on robust wake steering control optimized for variable wind directions. In this paper, the design and analysis of a wake steering controller with wind direction variability is presented for a two-turbine array using the FLOw Redirection and Induction in Steady State (FLORIS) control-oriented wake model. First, the authors propose a method for modeling the turbulent and low-frequency components of the wind direction, where the slowly varying wind direction serves as the relevant input to the wake model. Next, we explain a procedure for finding optimal yaw offsets for dynamic wind conditions considering both wind direction and yaw position uncertainty. We then performed simulations with the optimal yaw offsets applied using a realistic yaw offset controller in conjunction with a baseline yaw controller, showing good agreement with the predicted energy gain using the probabilistic model. Using the Gaussian wake model in FLORIS as an example, we compared the performance of yaw offset controllers optimized for static and dynamic wind conditions for different turbine spacings and turbulence intensity values, assuming uniformly distributed wind directions. For a spacing of five rotor diameters and a turbulence intensity of 10 %, robust yaw offsets optimized for variable wind directions yielded an energy gain equivalent to 3.24 % of wake losses recovered, compared to 1.42 % of wake losses recovered with yaw offsets optimized for static wind directions. In general, accounting for wind direction variability in the yaw offset optimization process was found to improve energy production more as the separation distance increased, whereas the relative improvement remained roughly the same for the range of turbulence intensity values considered.
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Kirincich, Anthony. "Toward Real-Time, Remote Observations of the Coastal Wind Resource Using High-Frequency Radar". Marine Technology Society Journal 47, nr 4 (1.07.2013): 206–17. http://dx.doi.org/10.4031/mtsj.47.4.22.
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AbstractThere is now a large installed base of high-frequency (HF) coastal ocean radars in the United States able to measure surface currents on an operational basis. However, these instruments also have the potential to provide estimates of the spatially variable surface wind field over distances ranging from 10 to 200 km offshore. This study investigates the ability of direction-finding HF radars to recover spatial maps of wind speed and direction from the dominant first-order region radar returns using empirical models. Observations of radar backscatter from the Martha’s Vineyard Coastal Observatory HF radar system were compared to wind observations from an offshore tower, finding significant correlations between wind speed and the backscatter power for a range of angles between the wind and radar loop directions. Models for the directional spreading of wind waves were analyzed in comparison to data-based results, finding potentially significant differences between the model and data-based spreading relationships. Using empirical fits, radar-based estimates of wind speed and direction at the location of the in situ wind sensor had error rates of 2 m/s and 60°, which decreased with hourly averaging. Attempts to extrapolate the results to the larger domain illustrated that spatially dependent transfer functions for wind speed and direction appear possible for large coastal ocean domains based on a small number of temporary, or potentially mobile, in situ wind sensors.
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Wang, Lai, i Xi Tong Dong. "Influence of Earthquake Directions on Wind Turbine Tower under Seismic Action". Advanced Materials Research 243-249 (maj 2011): 3883–88. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.3883.
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Influence of earthquake directions on wind turbine tower under seismic action are numerically investigated in this paper. First, equations of motion and an integrated finite element model of a wind turbine system consisting of a rotor, a nacelle and a tower shaft are established. Second, the finite element modal analysis is discussed. Third, relationships between upper displacements in x, y directions and bottom bending stress when the angle is 0, 30, 45, 60, 90 degree respectively between earthquake directions and concentrated eccentric mass direction (x direction) are analyzed by adjusted Taft seismic wave .The results show that: seismic responses of a wind turbine tower are remarkable and seismic action may be the dominant factor in the design of wind turbine towers that located at a seismically active zone. Under different earthquake directions structure’s dynamic responses are different, 90 degree with regard to x direction is the most unfavorable direction. Both maximum upper displacements in x, y directions and bottom bending stress appear at 90 degree direction with regard to x direction.
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Casswell, S. A. "A wind-direction display system". Weather 53, nr 1 (styczeń 1998): 20–22. http://dx.doi.org/10.1002/j.1477-8696.1998.tb06335.x.
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Hadnagy, István. "Climatic conditions of wind energy use in the Polonyna Borzhava Mountains (Transcarpathia, Ukraine)". DRC Sustainable Future: Journal of Environment, Agriculture, and Energy 1, nr 2 (21.11.2020): 136–46. http://dx.doi.org/10.37281/drcsf/1.2.6.
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This paper deals with the statistical structure, seasonal peculiarities of wind climate at meteorological station Play (in Ukrainian: метеорологічна станція Плай, location: 48°40’1” N; 23°11’51” E, 1330 m above sea level) located in the Polonyna Borzhava Mountain of the North-Eastern Carpathians. Furthermore, it determines significant parameters of exploiting wind energy. Weibull distribution was applied to determine specific wind power and characterize its annual course. Wind speed was analyzed together with the available daily and yearly course of wind power. Wind power density determined by means of distribution parameters at Play is 169.0 W/m2 and 8.0-9.0 m/s winds yield most energy over the year. The minimum number of energetically utilizable wind hours is in summer, while its maximum is in spring. On the territory represented by the measuring point, a 3 m/s start-up speed wind turbine could operate 63% time over the year. Finally, the periods were specified, and those wind directions were chosen that are richer in wind energy than others. The most frequent characteristic wind direction with the highest mean velocity in each season is south-western; its average relative frequency is 34.4%. Mean speed of characteristic wind directions is 5.8 m/s. South-western wind direction yields 47% of the total energy.
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Chen, Sheng, Fangli Qiao, Chuan Jiang Huang i Biao Zhao. "Deviation of Wind Stress From Wind Direction Under Low Wind Conditions". Journal of Geophysical Research: Oceans 123, nr 12 (grudzień 2018): 9357–68. http://dx.doi.org/10.1029/2018jc014137.
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Zhao, Ke, i Chaofang Zhao. "Evaluation of HY-2A Scatterometer Ocean Surface Wind Data during 2012–2018". Remote Sensing 11, nr 24 (11.12.2019): 2968. http://dx.doi.org/10.3390/rs11242968.
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This study focuses on the evaluation of global Haiyang-2A satellite scatterometer (HSCAT) operational wind products from 2012 to 2018. In order to evaluate HSCAT winds, HSCAT operational wind products were collocated with buoy measurements and rainfall data. Error varieties under different atmospheric stratification and rainfall conditions were taken into consideration. After data quality control, the average bias and root mean square error (RMSE) between buoys and HSCAT data were 0.1 m/s and 1.3 m/s for wind speed, and 1° and 27° for wind direction, respectively. Especially, the varieties of the wind direction difference change a lot under non-neutral atmospheric conditions. HSCAT wind speeds are overestimated with an increasing rainfall rate while wind directions tend to be perpendicular to buoys’. In brief, the HSCAT wind product qualities are not stable during 2012 to 2018, especially for the data in 2015 and 2016. Atmospheric stratification and rain effects should be considered in wind retrieval and marine application.
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Widyantara, Helmy, Muhammad Rivai i Djoko Purwanto. "Wind direction sensor based on thermal anemometer for olfactory mobile robot". Indonesian Journal of Electrical Engineering and Computer Science 13, nr 2 (1.02.2019): 475. http://dx.doi.org/10.11591/ijeecs.v13.i2.pp475-484.
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A wind direction sensor has been implemented for many applications, such as navigation, weather, and air pollution monitoring. In an odor tracking system, the wind plays the important role to carry gas from its source. Therefore, the precise, low-cost, and effective wind direction sensor is required to trace the gas source. In this study, a new design of wind direction sensor has been developed using thermal anemometer principle with the main component of the positive temperature coefficient thermistor. Three anemometers each of which has different directions are used as inputs for the neural network to determine the direction of the wind automatically.The experimental results show that the wind sensor system is able to detect twelve wind directions. A mobile robot equipped with this sensor system can navigate to a wind source in the open air with a success rate of 80%.This system is expected to increase the success rate of the mobile robot in searching for dangerous leaking gas in the open air.
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LUCENA, Leandro Ricardo Rodrigues de, i Moacyr CUNHA FILHO. "LACUNARITY AS INDEX OF EVALUATION OF WIND DIRECTION IN PERNAMBUCO". REVISTA BRASILEIRA DE BIOMETRIA 37, nr 1 (25.03.2019): 95. http://dx.doi.org/10.28951/rbb.v37i1.362.
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Wind direction data were recorded from January 2008 to February 2011, at nine weather stations (Recife, Caruaru, Arcoverde, Garanhuns, Surubim, Floresta, Ibimirim, Serra Talhada and, Cabrobó), in the state of Pernambuco, Brazil, operated by the Instituto Nacional de Meteorology (INMET). Lacunarity analysis was performed in order to evaluate wind direction on those weather stations. In Recife the predominance of the wind was in the east (E)-southeast (SE) direction. In the agreste of the state of Pernambuco the predominant direction of the wind is the same one of Recife. In the Sertão of Pernambuco the wind predominates in the east (E)-sul (S) direction. Small values of lacunarity are caused by the presence of local winds, while large values of lacunarity are caused by lack of wind in a certain direction.
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Ye, Zheng Wei, i Yi Qiang Xiang. "Bridge Design Basic Wind Speed Based on the Joint Distribution of Wind Speed and Direction". Applied Mechanics and Materials 90-93 (wrzesień 2011): 805–12. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.805.
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Based on the method of separation of wind speed and direction variable, considering the wind direction frequency function, ascending order to calculate the probability of the actual distribution of the sample, extreme type Ⅰ (Gumbel) and three parameters of extreme type Ⅱ (Frechet) and extreme type Ⅲ (Weibull) probability distribution to fit the sample, this paper has analyzed the weather station observations of 34 consecutive years of the joint distribution of wind speed and direction near to a huge bridge, gained the basic design wind speed in different directions, comparatively analyzed the impact of the sampling interval of change on the basic wind speed as well. The results shows: wind speed in different directions at the same location or different sampling intervals samples of the wind speed sample may be subject to different types of extreme value distribution, should separately fitting; different wind direction frequency of extreme wind speed occurrence and the basic wind speed there are certain differences, taking into account the joint distribution of wind speed and direction is necessary to determine the design basic wind speed of the bridge, and will be conservative without considering the joint distribution; for the same sample wind speed matrix, the shorter the sampling intervals, the optimal distribution of the higher probability model fitting precision, the smaller the basic wind speed, the more economic and reasonable the results.
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Flügge, Martin, Mostafa Bakhoday-Paskyabi, Joachim Reuder i Omar El Guernaoui. "Wind Stress in the Coastal Zone: Observations from a Buoy in Southwestern Norway". Atmosphere 10, nr 9 (26.08.2019): 491. http://dx.doi.org/10.3390/atmos10090491.
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Several studies have focused on the investigation of the wind stress in open ocean conditions where coastal processes were negligible. However, the direction and magnitude of the wind stress vector in coastal areas are still not fully known due to the low number of available measurement datasets. Here, we present new observations of the wind stress magnitude and its deviation from the mean wind direction. The data were recorded from a surface buoy during a five-day measurement campaign in southwestern Norway and cover wind speeds up to 10 m s−1 and significant wave heights up to 3.5 m in a coastal area with a steeply sloping sea floor. The adjustment of the wind stress vector due to changes in the wind and the wave conditions is illustrated and discussed by means of seven sample cases associated with both wind-following swell, cross-swell and counter-swell conditions. For this purpose, the stress vector computed in the sonic anemometer’s orthogonal coordinate system is projected into a non-orthogonal wind-swell coordinate system with its components aligned with: (1) the local wind-generated waves propagating in the wind direction; and (2) the swell wave direction. The wind stress direction was found to deviate from the wind direction by more than 20° for 46% of the recorded wind-following swell and cross-swell cases and for 54% of the counter-swell cases. The wind stress magnitude was observed to approach zero during the counter-swell period, which suggest a decoupling between the sea surface and the atmospheric surface layer. This was further investigated by means of an idealized Large Eddy Simulation results. The results in this study provide additional experimental evidence that the wind stress direction in coastal areas with a steeply sloping sea floor is influenced by the swell waves, the wave age and the wave steepness when the wind blows from undisturbed open ocean directions. For landward wind directions, the influence of the land boundary layer can, possibly in combination with atmospheric stability, adjust the magnitude and direction of the wind stress.
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Zhang, Jian Guo, i Hui Min Zhuang. "Wind Tunnel Test of Symmetrical Twin-Tower Tall Building Model". Advanced Materials Research 919-921 (kwiecień 2014): 518–22. http://dx.doi.org/10.4028/www.scientific.net/amr.919-921.518.
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In this paper, taking symmetrical twin-tower tall building model as an example, a wind tunnel test with simultaneous surface pressure measurement, in 7 wind directions, was carried out. Integration of the surface pressures leads to base moment coefficient, of which the amplitude and frequency-domain characteristics were analyzed and compared with those of single tall building model. The result shows that mean value and root mean square of the interfering tower, in all wind directions, are basically the same as those of single tower, while in 0o wind direction, they differ greatly; mean value and root mean square of the interfered tower differ significantly, in every wind directions, from those of single tower. In 0o wind direction, the reduced spectrum of along-wind and across-wind base moment coefficient is greatly different from that of the single tower; in 90o wind direction, the along-wind base moment coefficient reduced spectrum for interfered tower is different from Davenport spectrum, while the peak value of across-wind base moment coefficient is half the corresponding value of single tower.
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Gao, Boya, Karl R. Wotton, Will L. S. Hawkes, Myles H. M. Menz, Don R. Reynolds, Bao-Ping Zhai, Gao Hu i Jason W. Chapman. "Adaptive strategies of high-flying migratory hoverflies in response to wind currents". Proceedings of the Royal Society B: Biological Sciences 287, nr 1928 (3.06.2020): 20200406. http://dx.doi.org/10.1098/rspb.2020.0406.
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Large migrating insects, flying at high altitude, often exhibit complex behaviour. They frequently elect to fly on winds with directions quite different from the prevailing direction, and they show a degree of common orientation, both of which facilitate transport in seasonally beneficial directions. Much less is known about the migration behaviour of smaller (10–70 mg) insects. To address this issue, we used radar to examine the high-altitude flight of hoverflies (Diptera: Syrphidae), a group of day-active, medium-sized insects commonly migrating over the UK. We found that autumn migrants, which must move south, did indeed show migration timings and orientation responses that would take them in this direction, despite the unfavourability of the prevailing winds. Evidently, these hoverfly migrants must have a compass (probably a time-compensated solar mechanism), and a means of sensing the wind direction (which may be determined with sufficient accuracy at ground level, before take-off). By contrast, hoverflies arriving in the UK in spring showed weaker orientation tendencies, and did not correct for wind drift away from their seasonally adaptive direction (northwards). However, the spring migrants necessarily come from the south (on warm southerly winds), so we surmise that complex orientation behaviour may not be so crucial for the spring movements.
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Doering, Che. "A NEW BACKGROUND SUBTRACTION METHOD FOR ASSESSING PUBLIC RADIATION EXPOSURE DUE TO RADON TRANSPORT FROM A URANIUM MINE". Radiation Protection Dosimetry 186, nr 4 (30.05.2019): 530–35. http://dx.doi.org/10.1093/rpd/ncz141.
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Abstract Environmental radon progeny concentration data for the Ranger mine in the Australian wet-dry tropics were analysed. Concentrations in air at public receptor locations correlated with wind direction and were generally higher when the wind had a southerly component. The regional setting suggested that correlations were due to geography rather than the mine. The line of best fit to the radon progeny data when plotted against angle of wind direction was used to estimate background concentrations when the wind was from the direction of the mine. This differed from the standard approach of averaging concentrations when the wind was not from the direction of the mine. Background concentrations in mine-related wind directions using the line of best fit approach were generally higher than those predicted from averaging, as mine-related wind directions included a southerly component. Estimates of mine-related doses to the public were generally lower as a result.
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Antonini, Enrico G. A., David A. Romero i Cristina H. Amon. "Improving CFD wind farm simulations incorporating wind direction uncertainty". Renewable Energy 133 (kwiecień 2019): 1011–23. http://dx.doi.org/10.1016/j.renene.2018.10.084.
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Torres, J. L., A. García, E. Prieto i A. de Francisco. "Characterization of wind speed data according to wind direction". Solar Energy 66, nr 1 (maj 1999): 57–64. http://dx.doi.org/10.1016/s0038-092x(99)00007-9.
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Song, Dongran, Jian Yang, Yao Liu, Mei Su, Anfeng Liu i Young Hoon Joo. "Wind direction prediction for yaw control of wind turbines". International Journal of Control, Automation and Systems 15, nr 4 (20.07.2017): 1720–28. http://dx.doi.org/10.1007/s12555-017-0289-6.
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van der Werf, Ivo, i Marcel van Gent. "Wave Overtopping over Coastal Structures with Oblique Wind and Swell Waves". Journal of Marine Science and Engineering 6, nr 4 (6.12.2018): 149. http://dx.doi.org/10.3390/jmse6040149.
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Most guidelines on wave overtopping over coastal structures are based on conditions with waves from one direction only. Here, wave basin tests with oblique wave attack are presented where waves from one direction are combined with waves from another direction. This is especially important for locations where wind waves approach a coastal structure under a specific direction while swell waves approach the coastal structure under another direction. The tested structure was a dike with a smooth and impermeable 1:4 slope. The test programme consisted of four types of wave loading: (1) Wind waves only: “sea” (approaching the structure with an angle of 45°), (2) Wind waves and swell waves from the same direction (45°), (3) Wind waves and swell waves, simultaneously from two different directions (45° and −45°, thus perpendicular to each other), and (4) Wind waves, simultaneously from two different directions (45° and −45°, thus perpendicular to each other). Existing guidelines on wave overtopping have been extended to predict wave overtopping discharges under the mentioned types of wave loading (oblique sea and swell conditions).
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Lacke, Matthew C., John A. Knox, John D. Frye, Alan E. Stewart, Joshua D. Durkee, Christopher M. Fuhrmann i Sarah M. Dillingham. "A Climatology of Cold-Season Nonconvective Wind Events in the Great Lakes Region". Journal of Climate 20, nr 24 (15.12.2007): 6012–22. http://dx.doi.org/10.1175/2007jcli1750.1.
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Abstract A 44-yr climatology of nonconvective wind events (NCWEs) for the Great Lakes region has been created using hourly wind data for 38 first-order weather stations during the months of November through April. The data were analyzed in terms of the two National Weather Service (NWS) criteria for a high-wind watch or warning: sustained winds of at least 18 m s−1 for at least 1 h or a wind gust of at least 26 m s−1 for any duration. The results indicate a pronounced southwest quadrant directional preference for nonconvective high winds in this region. Between 70% and 76% of all occurrences that satisfied the NWS criteria for NCWEs were associated with wind directions from 180° through 270°. Within the southwest quadrant, the west-southwest direction is preferred, with 14%–35% of all NCWEs coming from this particular compass heading. This directional preference is borne out in five out of six stations with high occurrences of cold-season NCWEs (Buffalo, New York; Dayton, Ohio; Lansing, Michigan; Moline, Illinois; Springfield, Illinois). Given the geographic spread of these stations, a nontopographic cause for the directional preference of cold-season NCWEs is indicated. The connection between NCWEs and low pressure systems found in this climatology and in case studies suggests that midlatitude cyclone dynamics may be a possible cause of the directional preference.
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Muñoz Arroyo, Gonzalo, i María Mateos-Rodríguez. "Do Seabirds Control Wind Drift during Their Migration across the Strait of Gibraltar? A Study Using Remote Tracking by Radar". Remote Sensing 14, nr 12 (10.06.2022): 2792. http://dx.doi.org/10.3390/rs14122792.
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This study presents data on the directional flying behaviour of the five most abundant seabird species migrating across the Strait of Gibraltar in relation to the wind, as observed from the north coast, based on radar tracking, and identified to species level by visual observations. A total of 318 seabird trajectories were analysed, illustrating the expected east–west or west–east movements in spring and autumn. We hypothesised that the seabirds that cross the Strait channel during their migrations would behave differently with respect to compensation for wind direction, depending on their flight styles, the migratory period, and the prevailing winds. In this regard, our results showed that flapping birds (Razorbill, Puffin, Northern Gannet, and Balearic shearwater) compensated for wind drift independently of the season and the predominant wind direction. This agrees with the theory that suggests that under moderate winds and whenever visual contact with the coastline is present (as in the case of our study), migrants should compensate for wind drift to avoid being drifted towards the coast, off their main direction of flight. However, Cory’s shearwater, an active gliding seabird with long, slender wings, showed an adaptive directional response to wind, allowing it to be drifted in spring when westerly tailwinds were prevalent, but compensated for wind in autumn, when both easterly and westerly winds were similarly frequent. This adaptive flight behaviour allows it to take advantage of the prevailing tailwinds in spring, gaining ground speed and saving energy during its passage through the Strait, while in autumn, more frequent headwind conditions and a more directional migration to the south may favour compensating for wind drift. Our results support the usefulness of bird radar as a remote tool for describing the pattern of animal movements in the marine environment, as well as their behavioural response to atmospheric conditions. These studies are particularly relevant in the current framework of climate change.
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Borghei, Leila, i Ramin Haghighi Khoshkho. "Effects of Wind on Hot Air Recirculation (HAR) Behavior". Applied Mechanics and Materials 110-116 (październik 2011): 2067–74. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.2067.
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The air-cooled condenser system is impacted greatly by many factors such as the wind speed, the direction of wind and arrangement of site equipments. This paper concentrates on the hot air recirculation phenomenon and its dependence on ambient winds are numerically simulated by using the computational fluid dynamics code, FLUENT. In this paper, two different wind directions (case A and case B) and wind speeds are considered: Results show that the hot air recirculation increases with the increment of velocity speed. Case A has a critical wind direction angle. Wind causes an air temperature increase at the fan inlet due to hot air recirculation, resulting in the deterioration of the heat transfer performance. The hot air recirculation is the main factor responsible for the reduction of heat rejection rate. In case A, fan inlet temperature is higher than case B. The peak value of the HAR occurs at 9 m/s in case A.
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Jiang, Haoyu. "Wind speed and direction estimation from wave spectra using deep learning". Atmospheric Measurement Techniques 15, nr 1 (3.01.2022): 1–9. http://dx.doi.org/10.5194/amt-15-1-2022.
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Abstract. High-frequency parts of ocean wave spectra are strongly coupled to the local wind. Measurements of ocean wave spectra can be used to estimate sea surface winds. In this study, two deep neural networks (DNNs) were used to estimate the wind speed and direction from the first five Fourier coefficients from buoys. The DNNs were trained by wind and wave measurements from more than 100 meteorological buoys during 2014–2018. It is found that the wave measurements can best represent the wind information about 40 min previously because the high-frequency portion of the wave spectrum integrates preceding wind conditions. The overall root-mean-square error (RMSE) of estimated wind speed is ∼1.1 m s−1, and the RMSE of the wind direction is ∼ 14∘ when wind speed is 7–25 m s−1. This model can be used not only for the wind estimation for compact wave buoys but also for the quality control of wind and wave measurements from meteorological buoys.
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Wei, Chih-Chiang. "Surface Wind Nowcasting in the Penghu Islands Based on Classified Typhoon Tracks and the Effects of the Central Mountain Range of Taiwan". Weather and Forecasting 29, nr 6 (1.12.2014): 1425–50. http://dx.doi.org/10.1175/waf-d-14-00027.1.
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Abstract The purposes of this study were to forecast the hourly typhoon wind velocity over the Penghu Islands, and to discuss the effects of the terrain of the Central Mountain Range (CMR) of Taiwan over the Penghu Islands based on typhoon tracks. On average, a destructive typhoon hits the Penghu Islands every 15–20 yr. As a typhoon approaches the Penghu Islands, its track and intensity are influenced by the CMR topography. Therefore, CMR complicates the wind forecast of the Penghu Islands. Six main typhoon tracks (classes I–VI) are classified based on typhoon directions, as follows: (I) the direction of direct westward movement across the CMR of Taiwan, (II) the direction of northward movement along the eastern coast of Taiwan, (III) the direction of northward movement traveling through Taiwan Strait, (IV) the direction of westward movement traveling through Luzon Strait, (V) the direction of westward movement traveling through the southern East China Sea (near northern Taiwan), and (VI) the irregular track direction. The adaptive network-based fuzzy inference system (ANFIS) and multilayer perceptron neural network (MLPNN) were used as the forecasting technique for predicting the wind velocity. A total of 49 typhoons from 2000 to 2012 were analyzed. Results showed that the ANFIS models provided high-reliability predictions for wind velocity, and the ANFIS achieved more favorable performance than did the MLPNN. In addition, a detailed discussion on the interaction of the CMR with the Penghu Islands based on various track directions is provided. For class I, the CMR is observed to have significantly influenced variations in wind speed when typhoons approached the Penghu Islands. In addition, the winds on the Penghu Islands were observed to have been influenced by the distance from the typhoon center to the Penghu Islands for all classes except class II.
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Schauberger, G., i M. Piringer. "Predicting odour impact using the Austrian odour dispersion model (AODM)". Water Science and Technology 44, nr 9 (1.11.2001): 197–204. http://dx.doi.org/10.2166/wst.2001.0539.
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Using a dispersion model to calculate ambient odour concentrations, the separation distance between livestock buildings and residential areas is defined by the odour impact criteria using a combination of a pre-selected odour threshold and an exceeding probability. The dynamic Austrian Odour Dispersion Model (AODM), a Gaussian model, is used to calculate the direction-dependent separation distances for several combinations of these two values, which represent the protection level of various land use categories. The calculated direction-dependent separation distances are a function of the prevailing wind velocity and atmospheric stability conditions. At a site in the Austrian North-alpine foreland, the direction-dependent separation distance (calculated on the basis of a two year time series of meteorological data) for pure residential areas (3% exceeding probability over the year for an odour threshold of 1 OU/m3) lies between 99 m (for northerly winds with a probability of less than 3%) and 362 m (for westerly winds with a probability of 34%). For west and east the main wind directions, odour sensation can be expected more often for higher wind velocities and a neutral or stable atmosphere around sunset. Northerly and southerly winds show the typical diurnal variation of a local valley wind system with predominantly northerly daytime up-valley and southerly night-time down-valley winds.
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Plant, William J., William C. Keller i Kenneth Hayes. "Simultaneous Measurement of Ocean Winds and Waves with an Airborne Coherent Real Aperture Radar". Journal of Atmospheric and Oceanic Technology 22, nr 7 (1.07.2005): 832–46. http://dx.doi.org/10.1175/jtech1724.1.
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Abstract A coherent, X-band airborne radar has been developed to measure wind speed and direction simultaneously with directional wave spectra on the ocean. The coherent real aperture radar (CORAR) measures received power, mean Doppler shifts, and mean Doppler bandwidths from small-resolution cells on the ocean surface and converts them into measurements of winds and waves. The system operates with two sets of antennas, one rotating and one looking to the side of the airplane. The rotating antennas yield neutral wind vectors at a height of 10 m above the ocean surface using a scatterometer model function to relate measured cross sections to wind speed and direction. The side-looking antennas produce maps of normalized radar cross section and line-of-sight velocity from which directional ocean wave spectra may be obtained. Capabilities of CORAR for wind and wave measurement are illustrated using data taken during the Shoaling Waves Experiment (SHOWEX) sponsored by the Office of Naval Research. Wind vectors measured by CORAR agree well with those measured by nearby buoys. Directional wave spectra obtained by CORAR also agree with buoy measurements and illustrate that offshore winds can produce dominant waves at an angle to the wind vector that are in good agreement with the measurements. The best agreement is produced using the Joint North Sea Wave Project (JONSWAP) parameterizations of the development of wave height and period with fetch.