38:
422:
high-frequency sound. An ultrasonic anemometer has two or three pairs of sound transmitters and receivers. Each transmitter constantly beams high-frequency sound to its receiver. Electronic circuits inside measure the time it takes for the sound to make its journey from each transmitter to the corresponding receiver. Depending on how the wind blows, some of the sound beams will be affected more than the others, slowing it down or speeding it up very slightly. The circuits measure the difference in speeds of the beams and use that to calculate how fast the wind is blowing.
410:
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mounted 10 m above ground level (and thus 64 m above sea level). During the cyclone, several extreme gusts of greater than 83 m/s (300 km/h; 190 mph; 161 kn; 270 ft/s) were recorded, with a maximum 5-minute mean speed of 49 m/s (180 km/h; 110 mph; 95 kn; 160 ft/s); the extreme gust factor was on the order of 2.27–2.75 times the mean wind speed. The pattern and scales of the gusts suggest that a
983:
430:, which are used to create the separate standing-wave patterns at ultrasonic frequencies. As wind passes through the cavity, a change in the wave's property occurs (phase shift). By measuring the amount of phase shift in the received signals by each transducer, and then by mathematically processing the data, the sensor is able to provide an accurate horizontal measurement of wind speed and direction.
50:
402:
209:
describes the difference in air pressure between two points in the atmosphere or on the surface of the Earth. It is vital to wind speed, because the greater the difference in pressure, the faster the wind flows (from the high to low pressure) to balance out the variation. The pressure gradient, when
466:
In the United States, the wind speed used in design is often referred to as a "3-second gust", which is the highest sustained gust over a 3-second period having a probability of being exceeded per year of 1 in 50 (ASCE 7-05, updated to ASCE 7-16). This design wind speed is accepted by most building
499:
Historically, wind speeds have been reported with a variety of averaging times (such as fastest mile, 3-second gust, 1-minute, and mean hourly) which designers may have to take into account. To convert wind speeds from one averaging time to another, the Durst Curve was developed, which defines the
370:
on 3 May, although another figure of 142 m/s (510 km/h; 320 mph; 276 kn; 470 ft/s) has also been quoted for the same tornado. Yet another number used by the Center for Severe
Weather Research for that measurement is 135 ± 9 m/s (486 ± 32 km/h;
306:
of 113.3 m/s (408 km/h; 253 mph; 220.2 kn; 372 ft/s) The wind gust was evaluated by the WMO Evaluation Panel, who found that the anemometer was mechanically sound and that the gust was within statistical probability and ratified the measurement in 2010. The anemometer was
421:
Unlike traditional cup-and-vane anemometers, ultrasonic wind sensors have no moving parts and are therefore used to measure wind speed in applications that require maintenance-free performance, such as atop wind turbines. As the name suggests, ultrasonic wind sensors measure the wind speed using
425:
Acoustic resonance wind sensors are a variant of the ultrasonic sensor. Instead of using time of flight measurement, acoustic resonance sensors use resonating acoustic waves within a small purpose-built cavity. Built into the cavity is an array of
386:
has winds of 2,400 m/s (8,600 km/h; 4,700 kn). In a press release, the
University announced that the methods used from measuring HD 189733b's wind speeds could be used to measure wind speeds on Earth-like exoplanets.
619:"The Icelandic Meteorological Office now uses the SI (Systeme Internationale d'Unites) measurement metres per second (m/s) other Nordic meteorological institutes have used this system for years with satisfactory results"
342:) may greatly exceed these values but have never been accurately measured. Directly measuring these tornadic winds is rarely done, as the violent wind would destroy the instruments. A method of estimating speed is to use
417:
An anemometer is one of the tools used to measure wind speed. A device consisting of a vertical pillar and three or four concave cups, the anemometer captures the horizontal movement of air particles (wind speed).
629:
International Civil
Aviation Organization – International Standards and Recommended Practices – Units of Measurement to be Used in Air and Ground Operations – Annex 5 to the Convention on International Civil
579:
Brun, P., Zimmermann, N.E., Hari, C., Pellissier, L., Karger, D.N. (preprint): Global climate-related predictors at kilometre resolution for the past and future. Earth Syst. Sci. Data
Discuss.
362:, marking the fastest winds ever observed by radar in history. In 1999, a mobile radar measured winds up to 135 m/s (490 km/h; 300 mph; 262 kn; 440 ft/s) during the
463:
Wind speed is a common factor in the design of structures and buildings around the world. It is often the governing factor in the required lateral strength of a structure's design.
470:
In Canada, reference wind pressures are used in design and are based on the "mean hourly" wind speed having a probability of being exceeded per year of 1 in 50. The reference
535:
318:
Currently, the second-highest surface wind speed ever officially recorded is 103.266 m/s (371.76 km/h; 231.00 mph; 200.733 kn; 338.80 ft/s) at the
812:
657:"Documentation and verification of the world extreme wind gust record: 113.3 m s–1 on Barrow Island, Australia, during passage of tropical cyclone Olivia"
599:
758:
673:
749:"Comparison of Tornado Damage Characteristics to Low-Altitude WSR-88D Radar Observations and Implications for Tornado Intensity Estimation"
186:
Wind speed is affected by a number of factors and situations, operating on varying scales (from micro to macro scales). These include the
593:
148:
920:
Kapartis, Savvas (1999) "Anemometer employing standing wave normal to fluid flow and travelling wave normal to standing wave"
413:
FT742-DM acoustic resonance wind sensor, one of the instruments now used to measure wind speed at Mount
Washington Observatory
748:
509:
363:
53:
Global distribution of wind speed at 10m above ground averaged over the years 1981–2010 from the CHELSA-BIOCLIM+ data set
500:
relation between probable maximum wind speed averaged over some number of seconds to the mean wind speed over one hour.
1023:
1013:
550:
295:
174:(ft/s) are also sometimes used to measure wind speeds. Historically, wind speeds have also been classified using the
140:
371:
302 ± 20 mph; 262 ± 17 kn; 443 ± 30 ft/s). However, speeds measured by
319:
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860:
842:
17:
271:
37:
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885:
935:
677:
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31:
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326:. The anemometer, specifically designed for use on Mount Washington, was later tested by the US
178:, which is based on visual observations of specifically defined wind effects at sea or on land.
762:
753:
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355:
699:
524:
467:
codes in the United States and often governs the lateral design of buildings and structures.
322:
Observatory 1,917 m (6,288 ft) above sea level in the US on 12 April 1934, using a
236:). The Rossby waves are themselves a different wind speed from that experienced in the lower
603:
359:
116:
409:
8:
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643:"The reason why sea winds are measured in knots at all has to do with maritime tradition"
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120:
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198:, and local weather conditions. There are also links to be found between wind speed and
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100:
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84:, usually due to changes in temperature. Wind speed is now commonly measured with an
81:
909:
616:
592:
Hogan, C. Michael (2010). "Abiotic factor". In Emily
Monosson; C. Cleveland (eds.).
358:
recorded winds up to 150 metres per second (340 mph; 540 km/h) inside the
770:
471:
450:
232:. These operate on a global scale and move from west to east (hence being known as
151:(ICAO) also recommends meters per second for reporting wind speed when approaching
144:
132:
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as freak weather conditions can drastically affect the flow velocity of the wind.
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211:
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for reporting wind speeds, and used amongst others in weather forecasts in the
112:
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Lyza, Anthony W.; Flournoy, Matthew D.; Alford, A. Addison (19 March 2024).
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Another tool used to measure wind velocity includes a GPS combined with
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to measure the wind speeds remotely. Using this method, a mobile radar (
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861:"5400mph winds discovered hurtling around planet outside solar system"
813:"Highest surface wind speed-Tropical Cyclone Olivia sets world record"
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303:
299:
676:. World Meteorological Association. 5 November 2015. Archived from
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96:
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382:. Scientists at the University of Warwick in 2015 determined that
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is primarily used to determine the air velocity of an aircraft.
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play a key role in influencing wind speed, as the formation of
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rates of many plant species, and countless other implications.
270:
The original anemometer that measured The Big Wind in 1934 at
202:, notably with the pressure gradient and terrain conditions.
959:
NBC 2005 Structural
Commentaries – Part 4 of Div. B, Comm. I
49:
66:
338:
Wind speeds within certain atmospheric phenomena (such as
459:
Anemometer on an outdoor stage set, to measure wind speed
512:(promulgator of ASCE 7-05, current version is ASCE 7-16)
27:
Rate at which air moves from high- to low-pressure areas
662:. Australian Meteorological and Oceanographic Journal.
807:
805:
119:(and not perpendicular, as one might expect), due to
845:. Center for Severe Weather Research. Archived from
536:
ICAO recommendations – International System of Units
968:
ASCE 7-05 commentary Figure C6-4, ASCE 7-10 C26.5-1
722:"Massive Okla. tornado had windspeed up to 200 mph"
886:"Make and Use an Anemometer to measure Wind Speed"
802:
746:
910:https://www.explainthatstuff.com/anemometers.html
405:Modern day anemometer used to capture wind speed.
286:ever recorded was during the passage of Tropical
155:, replacing their former recommendation of using
995:
600:National Council for Science and the Environment
759:National Oceanic and Atmospheric Administration
181:
740:
139:for velocity and the unit recommended by the
162:For historical reasons, other units such as
617:Windspeed | Icelandic Meteorological office
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149:International Civil Aviation Organization
908:Chris Woodford. Ultrasonic anemometers.
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36:
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45:is commonly used to measure wind speed.
14:
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837:
282:The fastest wind speed not related to
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581:https://doi.org/10.5194/essd-2022-212
375:are not considered official records.
700:"The story of the world record wind"
510:American Society of Civil Engineers
311:was embedded in the already-strong
76:quantity caused by air moving from
24:
437:. A fluid flow velocity tool, the
378:Wind speeds can be much higher on
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477:is calculated using the equation
141:World Meteorological Organization
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320:Mount Washington (New Hampshire)
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767:American Meteorological Society
364:1999 Bridge Creek–Moore tornado
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702:. Mount Washington Observatory
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551:Saffir–Simpson Hurricane Scale
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330:and confirmed to be accurate.
228:are strong winds in the upper
115:is usually almost parallel to
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1:
641:Measuring Wind Speed in Knots
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354:) owned and operated by the
272:Mount Washington Observatory
182:Factors affecting wind speed
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798:. National Weather Service.
530:International Building Code
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10:
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29:
1024:Weather extremes of Earth
1014:Meteorological quantities
532:(promulgator of NBC 2005)
292:automatic weather station
674:"World record wind gust"
244:Local weather conditions
126:
30:Not to be confused with
775:10.1175/MWR-D-23-0242.1
492:is the air density and
328:National Weather Bureau
302:, registered a maximum
796:"Historical Tornadoes"
763:University of Oklahoma
754:Monthly Weather Review
460:
428:ultrasonic transducers
414:
406:
356:University of Oklahoma
274:
54:
46:
936:"Wind and Structures"
923:U.S. patent 5,877,416
595:Encyclopedia of Earth
525:Enhanced Fujita Scale
458:
412:
404:
373:Doppler weather radar
290:on 10 April 1996: an
269:
107:projects, growth and
52:
40:
990:at Wikimedia Commons
817:World Record Academy
680:on December 18, 2023
445:Design of structures
360:2013 El Reno tornado
843:"Doppler On Wheels"
598:. Washington D.C.:
496:is the wind speed.
324:hot-wire anemometer
157:kilometers per hour
93:weather forecasting
91:Wind speed affects
72:, is a fundamental
461:
415:
407:
275:
218:, also influences
210:combined with the
55:
47:
986:Media related to
819:. 26 January 2010
344:Doppler on Wheels
207:Pressure gradient
188:pressure gradient
147:. Since 2010 the
16:(Redirected from
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602:. Archived from
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451:Wind engineering
315:of the cyclone.
145:Nordic countries
133:meter per second
121:Earth's rotation
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212:Coriolis effect
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172:feet per second
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884:Koen, Joshua.
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849:on 2011-07-19.
839:Wurman, Joshua
830:
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606:on 2013-06-08.
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561:Wind direction
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516:Beaufort scale
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449:Main article:
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395:Main article:
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348:Doppler radars
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288:Cyclone Olivia
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220:wind direction
200:wind direction
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176:Beaufort scale
164:miles per hour
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113:Wind direction
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135:(m/s) is the
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18:Wind velocity
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944:. Retrieved
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868:. Retrieved
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847:the original
833:
821:. Retrieved
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778:. Retrieved
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730:. Retrieved
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704:. Retrieved
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682:. Retrieved
678:the original
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604:the original
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521:Fujita scale
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278:Non-tornadic
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226:Rossby waves
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192:Rossby waves
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130:
105:construction
103:operations,
90:
82:low pressure
62:
56:
942:(in Korean)
684:12 February
556:TORRO scale
541:Knot (unit)
391:Measurement
238:troposphere
230:troposphere
196:jet streams
74:atmospheric
59:meteorology
1019:Wind power
998:Categories
988:Wind speed
946:2018-04-18
895:2018-04-18
870:2020-08-08
706:26 January
567:References
439:Pitot tube
435:pitot tube
397:Anemometer
384:HD 189733b
380:exoplanets
346:or mobile
309:mesovortex
248:hurricanes
234:westerlies
170:(kn), and
109:metabolism
86:anemometer
70:flow speed
63:wind speed
43:anemometer
340:tornadoes
304:wind gust
300:Australia
284:tornadoes
1009:Airspeed
841:(2007).
780:19 March
765:via the
726:CBS News
630:Aviation
504:See also
488:, where
368:Oklahoma
334:Tornadic
256:cyclones
252:monsoons
216:friction
159:(km/h).
101:maritime
97:aviation
32:Airspeed
484:ρv
313:eyewall
166:(mph),
153:runways
137:SI unit
117:isobars
823:17 May
732:17 May
490:ρ
352:RaXPol
254:, and
660:(PDF)
168:knots
127:Units
65:, or
1004:Wind
825:2014
782:2024
761:and
734:2014
708:2010
686:2017
523:and
214:and
205:The
131:The
99:and
78:high
67:wind
771:doi
486:/ 2
366:in
294:on
80:to
57:In
41:An
1000::
938:.
888:.
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815:.
804:^
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648:^
482:=
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88:.
61:,
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773::
736:.
710:.
688:.
494:v
480:q
475:q
34:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
