scholarly journals Analysis of the Duration of High Winds During Landfalling Hurricanes

2021 ◽  
Vol 7 ◽  
Author(s):  
Gregory A. Kopp ◽  
Si Han Li ◽  
H. P. Hong
Keyword(s):  
Wind Speed ◽  
The United States ◽  
Risk Category ◽  
Wind Speeds ◽  
Speed Level ◽  
Design Wind Speed ◽  
Building Components ◽  
Components And Cladding ◽  
Peak Pressures ◽  
High Winds

The duration of wind storms over a threshold wind speed value is known to be an important parameter in determining damage and losses, with losses tending to increase with the duration. This is because peak pressures tend to increase with longer duration, many building components and cladding systems are vulnerable to different types of fatigue mechanisms, and the yielding of linear elastic materials in the plastic range depends on the number of load cycles. A hurricane model was used to examine the duration of high winds in the United States at Miami, Galveston, and Charleston with the goal of establishing duration statistics for hurricanes as a function of peak wind speed. It was found that the duration of high winds, defined as the time that the 10 min wind speeds are within 30% of the peak 10 min wind speed, had a significant variation with a range from tens of minutes to more than 20 h, depending on location. The median duration ranged from 1.5 to 4 h at the three locations, depending on location and the design wind speed level (i.e., the risk Category of the building). These results were used to establish a simple normalized model for wind speed as a function of time, which could be used together with the design wind speed to establish load cycles for design.

scholarly journals Catch Characteristics of Precipitation Gauges in High-Latitude Regions with High Winds

2006 ◽  
Vol 7 (5) ◽  
pp. 984-994 ◽  
Author(s):  
Konosuke Sugiura ◽  
Tetsuo Ohata ◽  
Daqing Yang
Keyword(s):  
Wind Speed ◽  
High Latitude ◽  
Cold Climate ◽  
Strong Wind ◽  
Blowing Snow ◽  
High Wind ◽  
Wind Speeds ◽  
Solid Precipitation ◽  
High Winds ◽  
Correction Equations

Abstract Intercomparison of solid precipitation measurement at Barrow, Alaska, has been carried out to examine the catch characteristics of various precipitation gauges in high-latitude regions with high winds and to evaluate the applicability of the WMO precipitation correction procedures. Five manual precipitation gauges (Canadian Nipher, Hellmann, Russian Tretyakov, U.S. 8-in., and Wyoming gauges) and a double fence intercomparison reference (DFIR) as an international reference standard have been installed. The data collected in the last three winters indicates that the amount of solid precipitation is characteristically low, and the zero-catch frequency of the nonshielded gauges is considerably high, 60%–80% of precipitation occurrences. The zero catch in high-latitude high-wind regions becomes a significant fraction of the total precipitation. At low wind speeds, the catch characteristics of the gauges are roughly similar to the DFIR, although it is noteworthy that the daily catch ratios decreased more rapidly with increasing wind speed compared to the WMO correction equations. The dependency of the daily catch ratios on air temperature was confirmed, and the rapid decrease in the daily catch ratios is due to small snow particles caused by the cold climate. The daily catch ratio of the Wyoming gauge clearly shows wind-induced losses. In addition, the daily catch ratios are considerably scattered under strong wind conditions due to the influence of blowing snow. This result suggests that it is not appropriate to extrapolate the WMO correction equations for the shielded gauges in high-latitude regions for high wind speed of over 6 m s−1.

scholarly journals Statistical Downscaling of Gridded Wind Speed Data Using Local Topography

2017 ◽  
Vol 18 (2) ◽  
pp. 335-348 ◽  
Author(s):  
Adam Winstral ◽  
Tobias Jonas ◽  
Nora Helbig
Keyword(s):  
Wind Speed ◽  
Statistical Downscaling ◽  
Surface Wind ◽  
Horizontal Resolution ◽  
Wind Data ◽  
Wind Fields ◽  
Forecast Performance ◽  
Wind Speeds ◽  
Mountain Environments ◽  
High Winds

Abstract Winds, particularly high winds, strongly affect snowmelt and snow redistribution. High winds during rain-on-snow events can lead to catastrophic flooding while strong redistribution events in mountain environments can generate dangerous avalanche conditions. To provide adequate warnings, accurate wind data are required. Yet, mountain wind fields exhibit a high degree of heterogeneity at small spatial lengths that are not resolved by currently available gridded forecast data. Wind data from over 200 stations across Switzerland were used to evaluate two forecast surface wind products (~2- and 7-km horizontal resolution) and develop a statistical downscaling technique to capture these finer-scaled heterogeneities. Wind exposure metrics derived from a 25-m horizontal resolution digital elevation model effectively segregated high, moderate, and low wind speed sites. Forecast performance was markedly compromised and biased low at the exposed sites and biased high at the sheltered, valley sites. It was also found that the variability of predicted wind speeds at these sites did not accurately represent the observed variability. A novel optimization scheme that accounted for local terrain structure while also nudging the forecasted distributions to better match the observed distributions and variability was developed. The resultant statistical downscaling technique notably decreased biases across a range of elevations and exposures and provided a better match to observed wind speed distributions.

scholarly journals An Examination of Wind Decay, Sustained Wind Speed Forecasts, and Gust Factors for Recent Tropical Cyclones in the Mid-Atlantic Region of the United States

2015 ◽  
Vol 30 (1) ◽  
pp. 153-176 ◽  
Author(s):  
Bryce Tyner ◽  
Anantha Aiyyer ◽  
Jonathan Blaes ◽  
Donald Reid Hawkins
Keyword(s):  
Surface Roughness ◽  
Wind Speed ◽  
Tropical Cyclones ◽  
Surface Wind ◽  
Software Tool ◽  
Weather Forecast ◽  
The United States ◽  
Atlantic Region ◽  
Wind Speeds ◽  
Gust Factors

Abstract In this study, several analyses were conducted that were aimed at improving sustained wind speed and gust forecasts for tropical cyclones (TCs) affecting coastal regions. An objective wind speed forecast analysis of recent TCs affecting the mid-Atlantic region was first conducted to set a benchmark for improvement. Forecasts from the National Digital Forecast Database were compared to observations and surface wind analyses in the region. The analysis suggests a general overprediction of sustained wind speeds, especially for areas affected by the strongest winds. Currently, National Weather Service Weather Forecast Offices use a software tool known as the Tropical Cyclone Forecast/Advisory (TCM) wind tool (TCMWindTool) to develop their wind forecast grids. The tool assumes linear decay in the sustained wind speeds when interpolating the National Hurricane Center 12–24-hourly TCM product to hourly grids. An analysis of postlandfall wind decay for recent TCs was conducted to evaluate this assumption. Results indicate that large errors in the forecasted wind speeds can emerge, especially for stronger storms. Finally, an analysis of gust factors for recent TCs affecting the region was conducted. Gust factors associated with weak sustained wind speeds are shown to be highly variable but average around 1.5. The gust factors decrease to values around 1.2 for wind speeds above 40 knots (kt; 1 kt = 0.51 m s−1) and are in general insensitive to the wind direction, suggesting local rather than upstream surface roughness largely dictates the gust factor at a given location. Forecasters are encouraged to increase land reduction factors used in the TCMWindTool and to modify gust factors to account for factors including the sustained wind speed and local surface roughness.

scholarly journals Homogenization and Trend Analysis of Canadian Near-Surface Wind Speeds

2010 ◽  
Vol 23 (5) ◽  
pp. 1209-1225 ◽  
Author(s):  
Hui Wan ◽  
Xiaolan L. Wang ◽  
Val R. Swail
Keyword(s):  
Wind Speed ◽  
Trend Analysis ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
The United States ◽  
Homogeneity Test ◽  
Near Surface ◽  
Wind Speeds ◽  
Long Term Trends

Abstract Near-surface wind speeds recorded at 117 stations in Canada for the period from 1953 to 2006 were analyzed in this study. First, metadata and a logarithmic wind profile were used to adjust hourly wind speeds measured at nonstandard anemometer heights to the standard 10-m level. Monthly mean near-surface wind speed series were then derived and subjected to a statistical homogeneity test, with homogeneous monthly mean geostrophic wind (geowind) speed series being used as reference series. Homogenized monthly mean near-surface wind speed series were obtained by adjusting all significant mean shifts, using the results of the statistical test and modeling along with all available metadata, and were used to assess the long-term trends. This study shows that station relocation and anemometer height change are the main causes for discontinuities in the near-surface wind speed series, followed by instrumentation problems or changes, and observing environment changes. It also shows that the effects of artificial mean shifts on the results of trend analysis are remarkable, and that the homogenized near-surface wind speed series show good spatial consistency of trends, which are in agreement with long-term trends estimated from independent datasets, such as surface winds in the United States and cyclone activity indices and ocean wave heights in the region. These indicate success in the homogenization of the wind data. During the period analyzed, the homogenized near-surface wind speed series show significant decreases throughout western Canada and most parts of southern Canada (except the Maritimes) in all seasons, with significant increases in the central Canadian Arctic in all seasons and in the Maritimes in spring and autumn.

scholarly journals Numerical study of the effect of geometry variation on the performance of innovative design wind speed enhancer

2018 ◽  
Vol 42 ◽  
pp. 01013
Author(s):  
Theodorus T. Wibowo ◽  
Faizal H. Daulay ◽  
Kutut Suryopratomo ◽  
Rachmawan Budiarto
Keyword(s):  
Wind Speed ◽  
Numerical Study ◽  
Ground Surface ◽  
Innovative Design ◽  
Wind Speeds ◽  
Design Wind Speed ◽  
Throat Diameter ◽  
Low Wind Speeds ◽  
The Cost ◽  
Better Than

Low wind speeds is one of the challenges of wind energy in several countries. The innovative design of wind speed enhancer is one of many solution of those challenges. The wind speed enhancer using the principle of constriction where the speed will be increased at a narrower area. The innovative design wind speed enhancer is unique because of the wind turbines are installed close to the ground surface. The uniqueness can reduce the cost of installation, maintenance, and can reduce the possibility of damage caused by lightning. The proposed of wind speed enhancer design was shown to be successful in increasing the wind speed at venturi that reach 2.26 faster than wind speed at environment for variation of the funnel gap and 2.35 faster than wind speed at environment for variation of the throat diameter. This result is better than existing design. The results of this study is 21.5% better than existing design for variation of funnel gap and 24.2% better than existing design for variation of the throat diameter.

scholarly journals Inconsistencies in the “New” Windchill Chart at Low Wind Speeds

2006 ◽  
Vol 45 (5) ◽  
pp. 787-790 ◽  
Author(s):  
Avraham Shitzer ◽  
Richard de Dear
Keyword(s):  
Wind Speed ◽  
Convective Heat Exchange ◽  
The United States ◽  
Exchange Coefficient ◽  
Heat Exchange Coefficient ◽  
Wind Speeds ◽  
Speed Condition ◽  
Air Temperatures ◽  
Low Wind Speeds ◽  
Calm Wind

Abstract An apparent error was detected in the calculation of windchill equivalent temperatures (WCETs) in the “new” chart and corresponding equation that were adopted in 2001 by the weather services in the United States and Canada. The problem is caused by significant discontinuities in WCETs at the assumed “calm” wind speed condition of 1.34 m s−1. As a result, published WCETs are not equal to, as they should be by definition, but are lower than air temperatures at the assumed calm wind speed condition. This inconsistency further propagates to higher wind speeds beyond the assumed calm condition. In this paper, a straightforward correction is proposed to circumvent these inconsistencies of the new windchill. The proposed correction makes this transition gradual rather than abrupt by applying it to the expression used for estimating the effects of wind on the convective heat exchange coefficient between humans and their cold and windy environment.

scholarly journals OPTIMALISASI PEMANFAATAN DATA ARAH DAN KECEPATAN ANGIN POLA MONSUNAL UNTUK KAJIAN PEMETAAN POTENSI ENERGI ANGIN DI WILAYAH NUSA TENGGARA BARAT

2019 ◽  
Vol 3 ◽  
pp. 14
Author(s):  
Abdul Hamid Al Habib ◽  
Kholis Nur Cahyo ◽  
Prasetyo Umar Firdiyanto ◽  
Paulus Agus Winarso
Keyword(s):  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbines ◽  
Electrical Power ◽  
The West ◽  
Wind Speeds ◽  
Wind Potential ◽  
High Winds ◽  
Turbine Installation ◽  
Potential Area

<p class="AbstractEnglish"><strong>Abstract:</strong>  The National Institute of Aeronautics and Space (LAPAN) as of July 18 2017 released data that from 166 locations studied, there were 35 locations that had good wind potential with wind speeds above 5 meters per second at a height of 50 meters. Regions that have good wind speeds, one of which is West Nusa Tenggara (NTB). West Nusa Tenggara is an area that is crossed by monsunal wind patterns and is an island surrounded by beaches so that the West Nusa Tenggara region receives high winds. This can potentially be installed by wind turbines to be able to convert wind energy into electricity. Wind direction and speed data obtained from satellites are processed into average data then adjusted to the wind speed threshold that can rotate wind turbines. The results obtained are mapped using the GrADS application to determine the potential area for horizontal axis type wind turbine installation at a height of 10 meters based on monsunal pattern direction and wind speed. This study will provide recommendations on potential areas of wind energy and predictions of electrical power that will be generated from the use of these maps. The results of the study show that the West Nusa Tenggara region by utilizing wind energy can create electricity in a year totaling 14067.4026 kWh.</p><p class="KeywordsEngish"><strong>Abstrak:</strong> Lembaga Penerbangan dan Antariksa Nasional (LAPAN) per <strong><em>18 Juli 2017</em></strong> merilis data bahwa dari 166 lokasi yang diteliti, terdapat 35 lokasi yang mempunyai potensi angin yang bagus dengan kecepatan angin diatas 5 meter perdetik pada ketinggian 50 meter. Daerah yang mempunyai kecepatan angin bagus tersebut, salah satunya adalah wilayah Nusa Tenggara Barat (NTB). Nusa Tenggara Barat merupakan wilayah yang dilintasi oleh pola angin monsunal dan merupakan pulau yang dikelilingi oleh pantai sehingga wilayah Nusa Tenggara Barat menerima hembusan angin yang cukup tinggi. Hal ini dapat berpotensi untuk dipasang turbin angin untuk dapat mengkonversi energi angin menjadi energi listrik. Data arah dan kecepatan angin yang diperoleh dari satelit diolah menjadi data rata-rata kemudian disesuaikan ke dalam batas ambang kecepatan angin yang dapat memutar turbin angin. Hasil yang diperoleh tersebut dipetakan dengan menggunakan aplikasi GrADS guna menetukan wilayah yang berpotensi untuk pemasangan turbin angin jenis sumbu horizontal pada ketinggian 10 meter berdasarkan arah dan kecepatan angin pola monsunal. Penelitian ini akan memberikan rekomendasi wilayah potensi energi angin serta prediksi daya listrik yang akan dihasilkan dari pemanfaatan peta tersebut. Hasil penelitian menunjukan wilayah Nusa Tenggara Barat dengan memanfaatkan energi angin dapat menciptakan energi listrik dalam setahun berjumlah 14067.4026 kWh.</p>

scholarly journals BIRDS’ FLIGHT ENERGY PREDICTIONS AND APPLICATION TO RADAR-TRACKING STUDY

2013 ◽  
Vol 3 (03) ◽  
pp. 135
Author(s):  
Alex Matsyura ◽  
Kazimierz Jankowski ◽  
Marina Matsyura
Keyword(s):  
Wind Speed ◽  
Major Effect ◽  
Conservation Of Energy ◽  
Adverse Conditions ◽  
Wind Speeds ◽  
Spacing Variation ◽  
Wind Influence ◽  
Soaring Birds ◽  
High Winds ◽  
Wing Tip

<p>In offered research, we propose to observe diurnal soaring birds to check, whether there the positions of birds in formations are such, that the wing tip interval and depth meet the predictions of aerodynamic theory for achievement of maximal conservation of energy or predictions of the hypothesis of communication. We also can estimate, whether adverse conditions of a wind influence the ability of birds to support formation. We can assume that windy conditions during flight might make precision flight more difficult by inducing both unpredictable bird and vortex positions. To this, we need to found change in wing-tip spacing variation with increasing wind speed, suggesting or rejecting that in high winds bird skeins maintained similar variation to that on calm days. The interrelation between variation of mean depth and wind speed should prove this hypothesis. Little is known about the importance of depth, but in high winds the vortex is likely to break up more rapidly and its location become unpredictable the further back a bird flies; therefore, a shift towards skeins with more regular depths at high wind speeds may compensate for the unpredictability of the vortex locations. Any significant relationship between the standard deviation of wing-tip spacing and wind speed suggests that wind has a major effect on optimal positioning.</p> <p>Results of proposed study will be used also as the auxiliary tool in radar research of bird migration, namely in research of flight features of soaring birds. It is extremely important to determine all pertinent characteristics of flock for model species, namely flocking birds.</p> <p><em>Kew words: birds, flock, radar, flight</em></p><p> </p>

scholarly journals On Correlation between Wind and Wave Storms

2021 ◽  
Vol 9 (12) ◽  
pp. 1426
Author(s):  
Valentina Laface ◽  
Felice Arena
Keyword(s):  
Wind Speed ◽  
Wave Height ◽  
Significant Wave Height ◽  
The United States ◽  
Storm Events ◽  
Significant Wave ◽  
Wind Speeds ◽  
Wave Heights ◽  
Significant Wave Heights ◽  
Sea Storm

The paper is focused on the formulation of an adequate criterion for associating wave storm events to the generating wind storm ones, and on the study of correlation between their characteristic parameters. In this context, the sea storm definition commonly used for storm identification from significant wave height data is adapted for wind storm, by processing wind speed data. A sensitivity analysis is proposed as function of the storm thresholds aiming at identifying optimal combination of wind speed and significant wave height thresholds allowing the association of relatively large number of events ensuring high correlation between wind and wave storm parameters. The analysis is carried out using as input data wind speeds and significant wave heights from four meteorological (buoys and anemometers) stations of the National Data Buoy Center moored off the East Coast of the United States. Results reveal that an optimal threshold combination is achieved assuming both wind speed and significant wave height threshold as 1.5 time their respective averages.

scholarly journals A social Beaufort scale to detect high winds using language in social media posts

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Iain S. Weaver ◽  
Hywel T. P. Williams ◽  
Rudy Arthur
Keyword(s):  
Social Media ◽  
Wind Speed ◽  
Temporal Correlation ◽  
Weather Conditions ◽  
Local Area ◽  
High Wind ◽  
Wind Speeds ◽  
The Uk ◽  
The Relationship ◽  
High Winds

AbstractPeople often talk about the weather on social media, using different vocabulary to describe different conditions. Here we combine a large collection of wind-related Twitter posts (tweets) and UK Met Office wind speed observations to explore the relationship between tweet volume, tweet language and wind speeds in the UK. We find that wind speeds are experienced subjectively relative to the local baseline, so that the same absolute wind speed is reported as stronger or weaker depending on the typical weather conditions in the local area. Different linguistic tokens (words and emojis) are associated with different wind speeds. These associations can be used to create a simple text classifier to detect ‘high-wind’ tweets with reasonable accuracy; this can be used to detect high winds in a locality using only a single tweet. We also construct a ‘social Beaufort scale’ to infer wind speeds based only on the language used in tweets. Together with the classifier, this demonstrates that language alone is indicative of weather conditions, independent of tweet volume. However, the number of high-wind tweets shows a strong temporal correlation with local wind speeds, increasing the ability of a combined language-plus-volume system to successfully detect high winds. Our findings complement previous work in social sensing of weather hazards that has focused on the relationship between tweet volume and severity. These results show that impacts of wind and storms are found in how people communicate and use language, a novel dimension in understanding the social impacts of extreme weather.

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