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The ESA Aeolus mission is the first Doppler Wind Lidar (DWL) in space. The satellite's Atmospheric Laser Doppler Instrument (ALADIN) profiles winds in the lowest 30 km of the atmosphere, [...]

PROBLEM: Although there are multiple methods for measuring wind speed and direction, all of them have limitations. For example, radiosondes are expensive and not available over oceans, while tracking cloud [...]

A tornado occurred in Angus, Ontario, during the late afternoon hours of 17 June 2014. The authors conducted a damage investigation on the morning following the storm. The damage indicators support the classification of the tornado as an EF-2 on the Enhanced Fujita Scale, including the observation of several complete roof failures of recently-constructed, woodframe houses. Most of the damage to residential homes was contained along two streets, with the tornado appearing to have gone down the backyards between the two. In total, 101 houses were observed to have sustained some level of damage. The evidence suggests that the quality of construction likely affected the performance of failed roofs. A detailed fragility analysis was conducted to assess wind speeds associated with these failures of the roof-to-wall connections. An overturned and lofted box truck provided the opportunity to correlate this failure with adjacent, repetitive failures of roof sheathing, shingles, and garage doors. Key words: tornadoes, EF-Scale, wood-frame houses, low-rise buildings, wind loads. Une tornade s'est produite a Angus en Ontario, au cours des dernieres heures de l'apres-midi du 17 juin 2014. Les auteurs ont mene une enquete sur les dommages le lendemain matin de la tempete. Les indicateurs de dommage confortent la classification de la tornade comme <> sur l'echelle de Fujita amelioree, y compris l'observation de plusieurs defaillances totales de toit de maisons a charpente de bois construites recemment. La plupart des dommages aux residences etaient confines le long de deux rues, du me me coup la tornade semblait avoir descendu les arriere-cours entre les deux rues. Au total, on a observe 101 maisons ayant subi un certain niveau de dommage. Les donnees montrent que la qualite de la construction a vraisemblablement eu une incidence sur le rendement des toits endommages. Une analyse en detail sur la fragilite a ete realisee afin d'evaluer les vitesses du vent associees aux defaillances des raccordements toit-murs. Un camion a caisson renverse et projete en hauteur a fourni l'occasion de correler cette defaillance aux defaillances adjacentes et repetitives de voligeages, de bardeaux de toit et de portes de garage. [Traduit par la Redaction] Mots-cles: tornades, echelle de Fujita amelioree, maisons a charpente en bois, batiment bas, surcharges dues au vent., Introduction Wind speeds in tornadoes are rarely measured; rather, they are assessed indirectly by examining the damage following the storm and estimating the wind speeds that could have caused the [...]

Wind speeds achieved in a recently-developed wind tunnel that generates unprecedented turbulent conditions. Located at ForWind, the joint Center for Wind Energy Research of the Universities of Oldenburg, Hannover, and [...]

QWhat is new about these guidelines? AThe City of London Corporation's new wind microclimate guidelines provide the first framework for assessing the impact of planning applications on wind conditions. They [...]

Reference wind velocity pressures corresponding to specified return period wind speeds are provided in several Canadian design codes. A review of the two most recent editions of the National Building Code of Canada (NBCC) indicates that significant changes in some 50-year return period wind speeds, [V.sub.AH]-50, were introduced in the 2010 version of the NBCC-2010 compared to the previous NBCC-2005. The changes are due to analysis approaches, available wind records, and a re- examination of anemometer histories. To potentially improve the estimates of [V.sub.AH]-50, wind records in the Environment Canada HLY01 digital archive were processed. Two hundred and thirty-five meteorological stations are considered in the analysis, and height and exposure corrected annual maximum hourly-mean wind speed, [V.SUB.AH], are extracted. Statistical analysis and distribution fitting were carried out using the Gumbel distribution and generalized extreme value distribution and several fitting methods were employed. The results indicate that it is preferable to treat [V.SUB.AH] as a Gumbel variate, and to carry out the fit using the generalized least-squares method. Wind speed contour maps for Canada are developed based on the estimated [V.sub.AH]_T for T equal to 50,500, and 1000 years. A comparison of the maps of [V.sub.AH]-50 to those inferred from NBCC-2005 and NBCC-2010 shows that the developed map retains some of the smoothness of the wind speeds exhibited in NBCC-2010, while maintains the localized wind speed features presented in NBCC-2005. Results also show that the wind speed corresponding to the factored design wind load in NBCC- 2010 is associated with a return period ranging from 200 to 5000 years, but for 90% of stations considered, the range narrows to 300 to 900 years. Key words: wind speed, wind load, NBCC, Gumbel distribution, extreme value analysis. Les pressions de vitesse de reference du vent correspondant a des vitesses de vents periodiques sont fournies dans plusieurs codes de conception canadiens. Une revue des deux plus recentes editions du Code national du batiment du Canada (CNBC) indique que des changements importants a certaines vitesses de vent d'une periodicite de 50 ans, [V.sub.AH]-50, ont ete introduits dans l'edition de 2010 du CNBC-2010, par rapport a l'ancienne edition du CNBC-2005. Les changements sont dus aux approches analytiques, aux registres de vent disponibles et a un nouvel examen des historiques anemometriques. Dans le but de potentiellement ameliorer les estimations de [V.sub.AH]-50, les registres de vent dans l'archive numerique HLY01 d'Environnement Canada ont ete traites. Deux cent trente-cinq (235) stations meteorologiques ont ete utilisees dans l'analyse, puis la force et l'exposition [V.SUB.AH] ont ete extraites apres avoir corrige les vitesses de vent maximales horaires annuelles et moyennes. L'analyse statistique et l'ajustement de la distribution ont ete realises en utilisant la loi de Gumbel; une distribution generalisee des valeurs extremes et plusieurs methodes d'ajustement ont ete utilisees. Les resultats indiquent qu'il est preferable de traiter [V.SUB.AH] en tant que variante de la loi de Gumbel et de realiser l'ajustement en utilisant la methode generalisee des moindres carres. Les cartes d'isogrammes de vitesse pour le Canada sont developpees en se basant sur la [V.sub.AH].T, pour T egal a 50, 500 et 1000 ans. Une comparaison des cartes de [V.sub.AH]-50 a celles tirees des CNBC-2005 et CNBC-2010 montre que la carte developpee conserve une partie des caracteristiques de vitesses regulieres du vent du CNBC-2010, tout en maintenant les caracteristiques localisees de vitesse du vent presentees dans CNBC-2005. Les resultats montrent egalement que la vitesse de vent correspondant a la surcharge eolienne admissible ponderee dans le CNBC-2010 est associee a une periodicite variant de 200 a 5000 ans mais, pour 90 % des stations considerees, la plage se retrecit entre 300 a 900 ans. [Traduit par la Redaction] Mots-cles: vitesse du vent, surcharge eolienne, CNBC, loi de Gumbel, analyse des valeurs extremes., Introduction Wind loading is one of the basic environmental loads that must be considered to ensure satisfactory performance and reliability of buildings and structures. Information regarding the development of the [...]

The gust factor curve proposed by Durst in 1960 is widely used within the wind engineering community to convert gust wind speeds to different averaging periods, or to estimate peak gust wind speeds from a longer term mean wind speed. This note first compares the curve derived by Durst to the observed gust factors from the data runs used in his analysis, before considering an expanded analysis using additional data available in the data source used by Durst. When using only the data runs used by Durst it is found that the Durst gust factor curve underestimates the mean observed gust factors by 2%-5%. The use of an expanded data set leads to the reaasult that the Durst gust factor curve provides a reasonably good match to the mean observed gust factors for all gust averaging times considered. Key words: gust factor, wind speed, peak gust, time averaging. La courbe de l'effet de rafale proposee par Durst en 1960 est grandement utilisee en genie eolien pour convertir les vitesses des rafales en differentes periodes moyennes ou pour estimer les vitesses maximales des rafales a partir d'une moyenne a plus long terme de la vitesse du vent. La presente note compare tout d'abord la courbe derivee par Durst aux coefficient s de rafale observes des ensembles de donnees utilises dans son analyse, avant de tenir compte d'une analyse etendue utilisant les donnees additionnelles disponibles dans la source de donnees utilisee par Durst. En utilisant uniquement les ensembles de donnees utilises par Durst, il s'avere que la courbe de l'effet de rafale de Durst sous-estime de 2 a 5 % la moyenne des coefficients des rafales observees. L'utilisation d'un ensemble de donnees etendu montre que la courbe de l'effet de rafale de Durst correspond raisonnablement bien a la moyenne observee des effets de rafale pour tous les temps des moyennes de rafales consideres. Mots-cles : coefficient de rafale, vitesse du vent, rafale maximale, moyenne dans le temps [Traduit par la Redaction], 1. Introduction The gust factor curve first proposed by Durst (1960) is widely used within the wind engineering community to convert gust wind speeds to different averaging periods, or to [...]

The paper describes a novel method for predicting the appropriate extreme value distribution derived from an observed time series. The method is based on introducing a cascade of conditioning approximations to the exact extreme value distribution. This allows for a rational way of capturing dependence effects in the time series: The performance of the method is compared with that of the peaks-over-threshold method. [DOI: 10.1115/1.4001419] Keywords: sampled time series, extreme value statistics, empirical data

This paper presents a time series analysis of historical observations of wind speed in order to project future wind speed trends. For this study, 52 years of data have been used from seven suitable stations across the UK. Four parsimonious models have been employed, and the data were split into two different segments: the training and the validation data sets. During the fitting process, the optimum parameters for each model were determined in order to minimize the mean square error in the predictions. The results suggest that the seasonal pattern in wind speeds is the most important factor but that there is some monthly autocorrelation in the data, which can improve forecasts. This is confirmed by testing the four models with the model having considered both autocorrelation and seasonality achieving the smallest errors. The approach proposed for forecasting wind speeds a month ahead may be deemed useful to suppliers for purchasing base load in advance and to system operators for power system maintenance scheduling up to a month ahead. [DOI: 10.1115/1.4002346]

ABSTRACT Long-term wind speed variations were investigated for three midwestern cities including Indianapolis, IN; Cincinnati, OH; and Little Rock, AR in the continental United States. These cities were chosen because [...]

This paper presents an overview of the approach employed in the development of the wind speed maps for use in ASCE 7-10. The reason for a reduction in the wind speeds in the new standard as compared to those given in the ASCE 7-98 through 7-05 standards is presented, as well as the reason for the reintroduction of Exposure D along the hurricane coastline. The most significant change in the wind speed maps from the previous version is the shift from a single map for an importance factor for buildings and other structures of 1.0 to three separate maps, one for each category of occupancy, thus eliminating the need for importance factors that vary between humcane and nonhurricane regions. DOI: 10.1061/(ASCE)ST.1943-541X.0000145 CE Database subject headings: Hurricanes; Risk management; Wind loads; Structural design; Wind speed; Wind gusts. Author keywords: Hurricane; Risk; Wind loads; ASCE-7; Design.

The Philippines has good potential for wind energy utilization. However, it is also prone to strong typhoons. Thus, wind turbines that will be erected in these areas maybe categorized into a special safety class and the reference wind speed is left to the discretion of the designer. Due to this scenario, the writers proposed a new reference wind speed applicable to Philippine climate which take typhoons into account. Annual extreme wind speeds gathered from fifty weather stations around the country were fitted to a generalized extreme value distribution. For each station, buckling failure of a wind turbine was analyzed using reliability theory. Based on these results a new 50-year mean wind speed and a new reference wind speed for a wind turbine in typhoon-prone areas in the Philippines are proposed. DOI: 10.1061/(ASCE)0733-9445(2010)136:4(463) CE Database subject headings: Buckling; Failures; Typhoons; Wind speed; Philippine Islands. Author keywords: Buckling failure; Wind turbine; Typhoons; New reference wind speed.

The wind speed profile for the neutral boundary layer is derived for a number of mixing-length parameterizations, which account for the height of the boundary layer. The wind speed profiles show good agreement with the reanalysis of the Leipzig wind profile (950 m high) and with combined cup-sonic anemometer and lidar measurements (300 m high) performed over flat and homogeneous terrain at Hovsore, Denmark. In the surface layer, the mixing-length parameterizations agree well with the traditional surface-layer theory, but the wind speed profile is underestimated when the surface-layer scaling is extended to the entire boundary layer, demonstrating the importance of the boundary layer height as a scaling parameter. The turbulence measurements, performed up to 160-m height only at the Hovsore site, provide the opportunity to derive the spectral-length scales from two spectral models. Good agreement is found between the behaviors of the mixing- and spectral-length scales. DOI: 10.1175/2009JAMC2148.1

A stochastic hub-height wind speed estimation algorithm for wind turbines, which requires only the rotor angular velocity measurement in the presence of observation noise is proposed. It is assumed that the power curve and the total inertia of the rotor are known a priori. We use the maximum likelihood estimator to identify the hub-height wind speed, which is formulated as one of the state variables in the nonlinear model. The theory and algorithm are verified by both simulated and experimental data in the presence of measurement noise. The effects of the initial guess, the noise variance, and the time history are discussed. [DOI: 10.1115/1.4000604]

By extracting energy from the highly dynamic wind and wave fields that typify pelagic habitats, albatrosses are able to proceed almost exclusively by gliding flight. Although energetic costs of gliding are low, enabling breeding albatrosses to forage hundreds to thousands of kilometers from their colonies, these and time costs vary with relative wind direction. This causes albatrosses in some areas to route provisioning trips to avoid headwind flight, potentially limiting habitat accessibility during the breeding season. In addition, because female albatrosses have lower wing loadings than males, it has been argued that they are better adapted to flight in light winds, leading to sexual segregation of foraging areas. We used satellite telemetry and immersion logger data to quantify the effects of relative wind speed, sex, breeding stage, and trip stage on the ground speeds ([V.sub.g]) of four species of Southern Ocean albatrosses breeding at South Georgia. [V.sub.g] was linearly related to the wind speed component in the direction of flight ([V.sub.wf]), its effect being greatest on Wandering Albatrosses Diomedea exulans, followed by Black-browed Albatrosses Thalassarche melanophrys, Light-mantled Sooty Albatrosses Phoebatria palpebrata, and Gray-headed Albatrosses T. chrysostoma. Ground speeds at [V.sub.wf] = 0 were similar to airspeeds predicted by aerodynamic theory and were higher in males than in females. However, we found no evidence that this led to sexual segregation, as males and females experienced comparable wind speeds during foraging trips. Black-browed, Gray-headed, and Light-mantled Sooty Albatrosses did not engage in direct, uninterrupted bouts of flight on moonless nights, but Wandering Albatrosses attained comparable [V.sub.g] night and day, regardless of lunar phase. Relative flight direction was more important in determining [V.sub.g] than absolute wind speed. When birds were less constrained in the middle stage of foraging trips, all species flew predominantly across the wind. However, in some instances, commuting birds encountered headwinds during outward trips and tail winds on their return, with the result that [V.sub.g] was 1.0-3.4 m/s faster during return trips. This, we hypothesize, could result from constraints imposed by the location of prey resources relative to the colony at South Georgia or could represent an energy optimization strategy. Key words: albatrosses; ARGOS errors; central-place foraging; dynamic or gust soaring; flight speed; habitat preference; niche specialization; platform terminal transmitters, PTT; satellite tracking; seabird; sexual segregation; South Georgia.

A coupled biophysical model of the Strait of Georgia (SoG), British Columbia, Canada, has been developed and successfully predicts the timing of the spring phytoplankton bloom. The physical model is a one-dimensional vertical mixing model, using a K-profile parametrization of the boundary layer, forced with high frequency meteorological data. The biological model includes one phytoplankton class (microphytoplankton) and one nutrient source (nitrate). The spring bloom in the SoG occurs when phytoplankton receive enough light that their growth rates exceed their loss rates. The amount of light that the phytoplankton receive is a function of solar radiation and the depth of mixing. The model was used to determine what physical factors are controlling the phytoplankton losses and the light received by the phytoplankton. Wind was found to control the spring bloom arrival time, with strong winds increasing the mixing-layer depth and delaying the bloom. The amount of incoming solar irradiance, through amount of cloud cover, had a secondary effect. The freshwater input (primarily Fraser River discharge) had an insignificant effect on the timing. Increased freshwater flux increases the buoyancy flux and thus decreases the mixing-layer depth but also increases the strength of the estuarine circulation, increasing the advective loss. Nous avons elabore un modele biophysique couple du detroit de Georgie (SoG), Colombie-Britannique, Canada, qui predit avec succes le moment de la proliferation printaniere du phytoplancton. Le modele physique est un modele de brassage vertical unidimensionnel, avec un parametrage du profil K de la couche limite, force par des donnees meteorologiques de haute frequence. Le modele biologique comprend une classe de phytoplancton (le microphytoplancton) et une source de nutriments (le nitrate). La proliferation printaniere dans le SoG se produit lorsque le phytoplancton recoit assez de lumiere pour que son taux de croissance surpasse son taux de perte. La quantite de lumiere recue par le phytoplankton est fonction de la radiation solaire et de la profondeur du brassage. Le modele a servi a determiner quels facteurs physiques controlent les pertes du phytoplancton et la lumiere recue par le phytoplancton. Le vent controle le moment de l'arrive e de la proliferation printaniere; cependant, les vents forts augmentent la profondeur de la couche de melange et retardent la proliferation. La quantite d'eclairement solaire incident a un effet secondaire selon l'importance de la couverture nuageuse. L'apport d'eau douce (principalement le debit du Fraser) a un effet negligeable sur le calendrier de la proliferation. L'apport accru d'eau douce augmente le flux de flottabilite et diminue ainsi la profondeur de la couche de melange, mais augmente aussi la force de la circulation dans l'estuaire, accroissant ainsi les pertes par advection. [Traduit par la Redaction], Introduction The Strait of Georgia (SoG) is a semi-enclosed, deep sea (maximum depth 400 m) located off the coast of mainland British Columbia, Canada (Fig. 1). In the southern SoG, [...]

A theoretical model is developed to predict the wind-streamflow-driven gas-liquid transfer rate. When wind blows over the stream surface, turbulence is generated at both the air-water interface and the water-bed interface, which is the driving force of the surface renewal movement of water parcels. The total surface renewal rate is considered as the sum of the effective surface renewal rates driven by the turbulence generated at these two interfaces. The gas-liquid transfer rate is formulated as a function of the total surface renewal rate based on the surface renewal theory. The concept of serial resistance, shear velocity, and effective viscous layer play significant roles in the model development. This model correlates the gas-liquid transfer rate with the dynamic fluid parameters such as wind speed and stream velocity. The predictions of this model show good agreement with existing experimental data. This model can be applied to predict the gas-liquid transfer rate in wind-streamflow-driven systems. DOI: 10.1061/(ASCE)0733-9372(2009) 135:8(653) CE Database subject headings: Water resources; Environmental engineering; Mathematical models.

The FAO-56 Penman-Monteith combination equation (FAO-56 PM) has been recommended by the Food and Agriculture Organization of the United Nations (FAO) as the standard equation for estimating reference evapotranspiration ([ET.sub.0]). The FAO-56 PM equation requires the numerous weather data that are not available in the most of the stations. This paper examines the potential of FAO-56 PM equation in estimating the [ET.sub.0] under humid conditions from limited weather data. For this study, full weather data sets were collected from six humid weather stations from Serbia, South East Europe. FAO-56 reduced-set PM [ET.sub.0] estimates were in closest agreement with FAO-56 full set PM [ET.sub.0] estimates at the most of locations. The difference between FAO-56 full set PM [ET.sub.0] estimates and FAO-56 PM reduced-set [ET.sub.0] estimates generally increases by increasing the number of estimated weather parameters. Overall results indicate that FAO-56 reduced-set PM approaches mostly provided better results compared to Turc equation, adjusted Hargreaves equation and temperature-based RBF network. This fact strongly supports using the FAO-56 PM equation even in the absence of the complete weather data set. The minimum and maximum air temperature data and local default wind speed value are the minimum data requirements necessary to successfully use the FAO-56 PM equation under humid conditions. DOI: 10.1061/(ASCE)IR. 1943-4774.0000094 CE Database subject headings: Evapotranspiration; Air temperature; Radiation; Humidity; Wind speed; Weather data; Estimation.

Ice crystal terminal velocities govern the lifetime of radiatively complex, climatologically important, low-latitude tropopause cirrus clouds. To better understand cloud lifetimes, the terminal velocities of low-latitude tropopause cirrus cloud particles have been estimated using data from aircraft field campaigns. Data used in this study were collected during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) and the Pre-Aura Validation Experiment (Pre-AVE). Particle properties were measured with the NCAR video ice particle sampler (VIPS) probe, thus providing information about particles in a poorly understood size range. Data used in this study were limited to high-altitude nonconvective thin clouds with temperatures between -56[degrees] and -86[degrees]C. Realistic particle terminal velocity estimates require accurate values of particle projected area and mass. Exponential functions were used to predict the dimensional properties of ice particles smaller than 200 microns and were found to predict ice water content measurements well when compared to power-law representations. The shapes of the particle size distributions were found to be monomodal and were well represented by exponential or gamma functions. Incorporating these findings into terminal velocity calculations led to lower values of mass-weighted terminal velocities for particle populations than are currently predicted for low-latitude ice clouds. New parameterizations for individual particle properties as well as particle size distribution properties are presented and compared to commonly used parameterizations. Results from this study are appropriate for use in estimating the properties of low-latitude thin and subvisible cirrus at temperatures lower than -56[degrees]C.

Square lighting poles with sharp or round corners have been observed to exhibit large amplitude oscillations with a frequency that is near that of their first mode. This frequency is one order of magnitude lower than that of the vortex shedding frequency for the observed wind speeds. As such, lock-in resonance between the vortex shedding and the poles motions has been ruled out as the cause of these oscillations. In this work, numerical simulations of flows over square cylinders with different aspect ratios and cross-sectional shapes have been carried out to explore and quantify low-frequency variations of the aerodynamic forces and their sources. The results show that low-frequency components are a basic aspect of the flow over finite length cylinders and are associated with the three-dimensional flow characteristics near the free end of the cylinder. This aspect is related to the loss of synchronization of the vortex shedding which, in turn, results in variations of the mean drag coefficient along the cylinder. This ability to numerically simulate the flow over a lighting pole and detailed results, as presented here, could be used to overcome wind tunnel test limitations imposed by the size of the test section and blockage ratio, and of meeting geometric similarity requirements for high aspect ratio configurations. Consequently, results from such simulations could play an important role in improving code specifications which, to date, have been based on wind tunnel simulations. DOI: 10.1061/(ASCE) ST. 1943-541 X.0000034 CE Database subject headings: Wind loads; Poles; Cylinders; Lifting; Drag; Coefficients.

This paper examines L-band normalized radar cross section (NRCS) dependence on ocean surface wind. More than 90000 match-ups, each consisting of the L-band HH NRCS, incidence angles, wind speeds, and wind directions, were collected from the Phased-Array L-Band Synthetic Aperture Radar (PALSAR) and scatterometer wind vectors. Based on the match-ups, the L-band HH NRCS dependence on incidence angle and wind vector is modeled for 0-20-m/s wind speeds and 17[degrees]-43[degrees] incidence angles. The derived relation indicates that the wind sensitivity of the L-band NRCS is less than that of the C-band at moderate winds and large incidence angles, whereas comparable at stronger winds (> 10 m/s) and small incidence angles. The upwind--crosswind difference is amplified in the 10-15-m/s range followed by an almost zero amplitude from 4 to 8 m/s, which represents a clear phase shift with the C-band W and Ku-band HH models. Wind speeds are then estimated from the match-ups, based on the derived model function. A comparison with the reference scatterometer winds reveals a 0.05-m/s bias and a 1.85-m/s root mean square error, where crosswind data give rise to large errors due to low wind sensitivity at wind speeds of around 10 m/s, particularly at large incidence angles. The L-band NRCS behavior in strong winds (> 20 m/s), at which the C-band is saturated, was not determined in the current model due to the limited number of the match-ups. Index Terms--L-band geophysical model function (GMF), ocean surface wind-speed detection, Phased-Array L-Band Synthetic Aperture Radar (PALSAR), synthetic aperture radar (SAR).

Although Turkey enjoys very important wind energy potential, the studies of the exploration and utilization this potential are still less than the level needed. In this study, the wind energy potential and wind characteristics of Kayseri province and of its some counties, located in the Central Anatolian region, were investigated using the wind speeds data hourly recorded at 10 m hub height from the year 2000 to 2006. The observed wind data were processed as annual and seasonal by means of the FORTRAN computer code. Weibull and Rayleigh probability density functions of the location using actual data are calculated. For Pinarbasi County, in the considered years, Weibull shape parameter k and scale parameter c vary between values of 1.40 and 1.59 and 3.91 and 4.26 m/s, respectively. In Pinarbasi, the mean power density varies between 65 and 90 W/[m.sup.2] according to actual data while between 75 and 100 W/[m.sup.2] according to Weibull data. In addition, for Pinarbasi, the maximum value of the mean power density according to actual data for the winter season is 170 W/[m.sup.2] in 2001. Mean power density in all of the considered years for Pinarbasi is considerable in winter and spring. As a result, Pinarbasi, among the considered sites, has a remarkable potential of wind energy for utilization and can be evaluated as a marginal area for cost-effective electrical energy generation as the costs of wind energy conversion systems are lowered. CE Database subject headings: Wind energy; Turkey; Evaluation.

Unique wind ripples attaining heights to 2.3 m, wavelengths to 43 m, and a crest maximum grain size of 19 mm occur on the Argentine Puna Plateau at ~4000 m altitude. These are the largest ripples reported on Earth, comparable only to Mars counterparts. They form in the presence of high proportions of low-density pumice clasts (0.91 g/[cm.sup.3]), although crests are exclusively composed of varnished, normal-density clasts (2.43 g/[cm.sup.3]). Mature ripple profiles are partly excavated on bedrock, so they form by a combination of deflation, winnowing of finer grains, minor wind drift of fine gravel, and lagging of clasts >4 cm. The large ripple size appears to be related to strong winds, dense saltation layers, and a long time for evolution. Ripple sizes are smaller on obstacles, as compared to flat terrain; there is a lack of correlation between clast size, wavelength, and the extreme ripple size (in spite of the thin atmosphere), all of which suggest that while small-scale gravel ripples may form according to a reptation model, their evolution into large-scale types may relate to aerodynamic instabilities originating at the saltation curtain-air interface.

The QuikSCAT scatterometer is used to accurately retrieve winds over the ocean at both high (2.5 km) and low (2.5 km) resolutions. In near-coastal regions, land contamination of measurements results in inaccurate wind estimates using current techniques. Here, we show that identifying land-contaminated measurements allows wind retrieval to be accurately achieved in near-coastal regions using QuikSCAT data at up to 2.5-km resolution using the AVE algorithm. To identify and remove land contamination, two metrics are compared, namely, the minimum distance to land and the land contribution ratio (LCR). The LCR is used as a metric to identify and remove land-contaminated backscatter [[sigma].sup.o] measurements before wind retrieval by discarding measurements with LCR values above a threshold. LCR thresholds used to remove land-contaminated measurements are determined using Monte Carlo simulations and set during processing using a lookup table based on the local wind speed, land brightness, and the cross-track swath location. Wind retrieval from [[sigma].sup.o] fields generated using the LCR is more accurate closer to the coast than previously achieved using both low- and high-resolution processing. Index Terms--Wind, scattering.

In this study, wind energy density in the southern and southwestern region of Turkey was investigated by using the Weibull and Rayleigh probability density functions, and the wind atlas analysis and application program (WASP). Hourly wind speeds and directions collected by the General Directorate of Electrical Power Resources Survey Administration were used. Before the construction of the wind turbine generator in these locations, several fundamental properties of the site such as wind behavior, availability, continuity, and probability should be carried out in order to provide the necessary information to the potential investors about cost and economical aspects of planning the wind energy project. The dominant wind direction, probability distribution, Weibull parameters, mean wind speed and power potential of all stations were determined by the Weibull and Rayleigh models, and the WAsP program. The results obtained with these models were compared with the measured data. Finally, it is found that these regions have a reasonable wind power potential and they are suitable for planting wind energy turbines. However, Belen is the most promising and convenient site for production of electricity from wind power. CE Database subject headings: Parameters; Wind energy; Wind speed; Turkey.